Engine Control System - Tests W/codes - DTC p0205-p0351

MODEL IDENTIFICATION

Vehicle model is identified by fourth character (cars), or fifth character (trucks) of Vehicle Identification Number (VIN). VIN is stamped on metal pad on top of left end of instrument panel, near windshield. See MODEL IDENTIFICATION (CARS) table, or MODEL IDENTIFICATION (TRUCKS) table under MODEL IDENTIFICATION in INTRODUCTION article.

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Circuit Description

ECM will enable an injector on intake stroke of each cylinder. Ignition voltage is supplied directly to fuel injectors. ECM controls each injector by grounding control circuit via an internal driver.

Primary function of driver is to supply ground for component being controlled. Each driver has a fault line which is monitored by ECM. When ECM is commanding a component on, voltage of control circuit should be low (near zero). When ECM is commanding control circuit to component off, voltage potential of circuit should be high (near battery voltage). If fault detection circuit senses a voltage other than what is expected, this DTC will set.

ECM will monitor injector circuit for short to ground, short to voltage, open circuit or an internally shorted or excessively low resistance at injector. If ECM detects any of these malfunctions, this DTC will set and affected driver will be disabled. ECM will continue to test circuit and if fault disappears, driver will be reactivated.

Diagnostic Procedures

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current cylinder No. 5. If counter is increasing, go to next step. If counter is not increasing, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351__diagnostic-aids) .
Turn ignition off. Disconnect main fuel injector connector. Turn ignition on, with engine off. Using test light connected to battery voltage, probe injector No. 5 harness connector control circuit (ECM side). If test light is on, go to next step. If test light is off, go to step 6 .
Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. If test light is on, go to step 11 . If test light is off, go to next step.
Turn ignition on, with engine off. Using test light connected to ground, probe injector No. 5 harness connector control circuit (ECM side). If test light is on, go to step 12 . If test light is off, go to step 15 .
Crank engine. If test light blinks about once per second, go to step 8 . If test light does not blink about once per second, go to next step.
Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. Using DVOM, check harness continuity of injector No. 5 control circuit between main injector and ECM harness connectors. If continuity exists, go to step 14 . If continuity does not exist, go to step 10 .
Turn ignition off. Using a jumper wire, reconnect switched battery feed circuit in male half of main injector harness connector to switched battery feed circuit in female half of main injector harness connector. Using test light connected to ground, probe injector No. 5 harness connector control circuit (injector side). Turn ignition on, with engine off. If test light is on, go to step 13 . If test light is off, go to next step.
Check for poor connections and terminal tension at fuel injector harness connector or at main injector connector. Check injector control circuit for open, short to ground, or short to voltage between injector and main injector connector. Check for open in switched battery feed circuit between injector and wiring splice. Repair as necessary, and then go to step 16 . If connections, terminals and circuits are okay, go to step 13 .
Repair open or high resistance in injector control circuit. After repairs, go to step 16 .
Repair short to ground in injector control circuit. After repairs, go to step 16 .
Repair short to voltage in injector driver circuit. After repairs, go to step 16 .
Replace fuel injector. After replacing injector, go to step 16 .
Check for poor connections and terminal tension at ECM harness connector. Repair as necessary. After repairs, go to step 16 . If connections and terminals are okay, go to next step.
Replace ECM. New ECM must be programmed with theft deterrent module frequency code currently on vehicle. After replacing ECM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0205 is set, go to step 2 . If DTC P0205 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

Diagnostic Aids

Check for poor connections at ECM or at component. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connection.

Check for misrouted wiring harness. Inspect harness to ensure that it is not routed too close to high voltage wires (spark plug wires) or too close to high current devices (generator, motors, solenoids).

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault.

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

PCM controls fuel injector control circuit using an ignition feed driver and ground circuit within the PCM. The driver has the ability to detect an electrical malfunction in ignition feed or ground circuit. If an electrical malfunction occurs in fuel injector circuit for affected cylinder, ignition feed driver signals PCM to set DTC. Conditions for setting DTC

Engine running.
Incorrect voltage level being detected on an injector driver circuit.
Conditions present for at least 30 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor SPECIFIC DTC. If scan tool indicates that this DTC failed this ignition cycle, go to step 4 . If scan does not indicate that this DTC failed this ignition cycle, go to next step.
Turn ignition on, engine off. Using scan tool, review and record FAILURE RECORDS data. Operate vehicle in fail conditions parameter. If scan tool indicates that this DTC failed this ignition cycle, go to next step. If scan tool does not indicate that this DTC failed this ignition cycle, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using scan tool, enter OUTPUT DRIVER DATA menu. If scan tool indicates that cylinder No. 5 injector circuit is STUCK HIGH, go to step 6 . If scan tool does not indicate that cylinder No. 5 injector circuit is STUCK HIGH, go to next step.
If scan tool indicates that cylinder No. 5 injector circuit is STUCK LOW, go to step 10 . If scan tool does not indicate that cylinder No. 5 injector circuit is STUCK LOW, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect 10-pin fuel injector connector. Crank engine. While cranking engine, if scan tool indicates that cylinder No. 5 injector circuit is STUCK LOW, go to next step. If scan tool does not indicate that cylinder No. 5 injector circuit is STUCK LOW, go to step 9 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on, engine off. Check voltage between cylinder No. 5 fuel injector control circuit and ground. If voltage reading is battery voltage, go to next step. If voltage reading is not battery voltage, go to step 15 .
Locate and repair short to voltage in cylinder No. 5 fuel injector control circuit. After repairs, go to step 16 .
If scan tool indicates that No. 5 injector control circuit is STUCK LOW, check affected fuel injector. See appropriate SYSTEM & COMPONENT TESTING article.
Disconnect 10-pin fuel injector harness connector. Using a test light connected to battery voltage, probe injector No. 5 control circuit at PCM side of 10-pin connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
Disconnect PCM harness connector. Using a test light connected to battery voltage, probe injector No. 5 control circuit at PCM connector. If test light illuminates, go to step 14 . If test light does not illuminate, go to step 15 .
With test light still connected, crank engine. If test light flashes, check affected fuel injector. See appropriate SYSTEM & COMPONENT TESTING article. If test light does not flash, go to next step.
Check cylinder No. 5 injector driver circuit between 10-pin injector connector and PCM for an open circuit. Repair as necessary. After repairs, go to step 16 .
Locate and repair short to ground in fuel injector driver circuit between PCM and 10-pin injector connector. After repairs, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle with the FAILURE RECORDS conditions. Check for DTCs. If this DTC is set, go to step 2 . If this DTC is not set, system is okay.

Monitor injector fault parameter on scan tool. Wiggle electrical harnesses for affected electrical circuit. If status changes on tool, an intermittent problem is present. Check for poor connections at PCM. Check for damaged harness.

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.5L "W" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Ignition voltage is supplied directly to fuel injectors. PCM controls each fuel injector by grounding the control circuit through the internal solid state device called the driver.

Primary function of driver is to supply ground for component being controlled. Each driver has a fault line which is monitored by PCM. When PCM is commanding a component on, voltage of control circuit should be low (near zero). When PCM is commanding control circuit to component off, voltage potential of circuit should be high (near battery voltage). If fault detection circuit senses a voltage other than what is expected, this DTC will set.

ECM will monitor injector circuit for short to ground, short to voltage, open circuit or an internally shorted or excessively low resistance at injector. If PCM detects any of these malfunctions, this DTC will set and affected driver will be disabled. PCM will continue to test circuit and if fault disappears, driver will be reactivated. DTC is set when engine is running or when ignition voltage is 9-17 volts and PCM detects an incorrect voltage potential on the ignition control circuit.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor misfire current cylinder No. 5. If scan tool continuously indicates OK, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If scan tool does not continuously indicate OK, go to next step
If the entire bank of cylinders are inoperative, go to next step. If only some of the cylinders are inoperative, go to step 6 .
Check fuel injector fuses. If fuses are okay, go to next step. If fuses are not okay, go to step 11 .
Turn ignition off. Disconnect harness connector to affected fuel injector(s). Turn ignition on, engine off. Using a DVOM, check voltage between ground and ignition feed circuit in fuel injector harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 12 .
Using an Injector Test Light (J-34730-405), connect injector test light to injector harness connector. Crank engine. If engine starts, turn engine off after verifying test light. Repeat test on all affected injectors. If test light flashed on all of the injectors tested, go to step 18 . If test light did not flash on all or any of the injectors tested, go to next step.
Turn ignition off. Disconnect PCM harness connector. Using DVOM, check harness continuity of injector No. 5 control circuit between injector and PCM harness connectors. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 13 .
Check continuity between injector control circuit and ground. If resistance is infinite, go to next step. If resistance is not infinite, go to step 14 .
Turn ignition on, with engine off. Using DVOM, check for short to voltage in injector control circuit. If circuit is shorted to voltage, go to step 15 . If circuit is not shorted to voltage, go to next step.
Turn ignition off. Disconnect all fuel injector harness connectors. Using DVOM, check continuity between injector control circuits. If resistance is infinite, go to step 20 . If resistance is not infinite, go to step 16 .
Check for short to ground in injector ignition feed circuit. Repair as necessary. After repairs, go to step 22 . If circuit is okay, go to step 17 .
Repair open/high resistance in ignition feed circuit. After repairs, go to step 22 .
Repair open/high resistance in injector control circuit. After replacing injector, go to step 22 .
Repair injector control circuit that is shorted to ground. After repairs, go to step 22 .
Repair injector control circuit that is shorted to power. After repairs, go to step 22 .
Repair injector control circuits that are shorted together. After repairs, go to step 22 .
Test fuel injector coil. See appropriate SYSTEM & COMPONENT TESTING article. After testing fuel injector, go to step 22 .
Check for poor terminal connection at fuel injector harness connector. Repair as necessary. After repairs, go to step 22 . If connectors are okay, go to next step.
Replace fuel injector. After replacing fuel injector, go to step 22 .
Check for poor terminal connection at PCM harness connector. Repair as necessary. After repairs, go to step 22 . If connectors are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle within the conditions for setting this DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicates that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, review CAPTURED INFO. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Check for poor connections at PCM or at component. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connection.

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault.

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine running.
Incorrect voltage level being detected on an injector driver circuit.
Conditions present for at least 30 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor SPECIFIC DTC. If scan tool indicates that this DTC failed this ignition cycle, go to step 4 . If scan does not indicate that this DTC failed this ignition cycle, go to next step.
Turn ignition on, engine off. Using scan tool, review and record FAILURE RECORDS data. Operate vehicle in fail conditions parameter. If scan tool indicates that this DTC failed this ignition cycle, go to next step. If scan tool does not indicate that this DTC failed this ignition cycle, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on, engine off. Check voltage between cylinder No. 5 fuel injector control circuit and ground. If battery voltage is present, go to next step. If battery voltage is not present, go to step 9 .
Check fuel injectors. See appropriate SYSTEM & COMPONENT TESTING article. If injectors are okay, go to next step. If injectors are not okay, go to step 17 .
Turn ignition off. Disconnect cylinder No. 5 injector connector. Turn ignition on. Check voltage between ground and fuel injector No. 5 control circuit at PCM connector. If voltage reading is zero volts, go to next step. If voltage reading is not zero volts, go to step 16 .
Check for intermittent open in ignition feed circuit in harness between fuse and injector No. 5. Check for intermittent open in injector No. 5 control circuit between PCM and injector. Repair as necessary. After repairs, go to step 19 . If circuits are okay, go to next step.
Check for poor terminal connections at fuel injector No. 5 connector and injector No. 5 connection at PCM connector. Repair as necessary. After repairs, go to step 19 . If connections are okay, go to step 18 .
Turn ignition off. Disconnect injector No. 5 connector. Turn ignition on. Check voltage between ground and ignition feed circuit at injector No. 5 connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 14 .
Using a test light connected to battery voltage, probe test light to injector No. 5 control circuit. If test light illuminates, go to step 15 . If test light does not illuminate, go to next step.
Turn ignition off. Using a fused jumper wire, jumper injector No. 5 control circuit and ignition feed circuit at injector connector. Turn ignition on. Using test light connected to ground, probe injector No. 5 control circuit at PCM connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 13 .
Check for poor terminal contact at injector No. 5 connector. Repair as necessary. After repairs, go to step 19 . If connection is okay, go to step 17 .
Locate and repair open in injector No. 5 control circuit. After repairs, go to step 19 .
Locate and repair open or short to ground in injector No. 5 ignition feed circuit. After repairs, go to step 19 .
Locate and repair short to ground in injector No. 5 control circuit. After repairs, go to step 19 .
Locate and repair short to voltage in injector No. 5 control circuit. After repairs, go to step 19 .
Replace faulty injector. After replacing injector, go to step 19 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle with the FAILURE RECORDS conditions. Check for DTCs. If this DTC is set, go to step 2 . If this DTC is not set, system is okay.

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

The PCM contains a General Field Effect Transistor Driver (GFD) that controls the 8 fuel injector drivers. The GFD is used to determine if there is a problem with any of the fuel injector circuits. The GFD has a fault line for each injector. The fault line goes high when an open, short to ground, or short to voltage is noticed in an injector circuit. DTC will set when the fault line for an injector is high. Conditions for setting DTC

DTCs P0560 and P1376 not set.
Ignition voltage 10-16 volts.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on. Using scan tool, check if DTCs P0202, P0203 and P0208 are also present. If these DTCs are present, diagnose using DTC P0202 test. If these DTCs are not present, go to next step.
Using scan tool, select DTC INFO then LAST TST. FAIL mode. If this DTC failed its last test, go to step 5 . If this DTC does not show that it failed its last test, go to next step.
Clear DTCs and operate vehicle until DTC P0205 resets. If DTC P0205 resets, go to next step. If DTC P0205 does not reset, fault is not present.
Turn ignition off. Disconnect injector No. 5 harness connector. Turn ignition on. Check voltage between injector No. 5 harness connector terminal "A" and ground. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 13 .
Reconnect injector No. 5 harness connector. Store fluid life reading as indicated on scan tool. Turn ignition off for 30 seconds, then disconnect PCM harness connector C2. Turn ignition on. Check voltage between PCM harness connector C2 terminal No. 17 and ground. If voltage reading is greater than 10 volts, go to next step. If voltage reading is not greater than 10 volts, go to step 10 .
Disconnect injector No. 5 harness connector. Check resistance between injector terminals "A" and "B". If resistance is greater than 8 ohms, go to next step. If resistance is 8 ohms or less, go to step 18 .
Check voltage between injector No. 5 harness connector terminal "B". If voltage reading is 0.1 volt or less, go to next step. If voltage reading is greater than 0.1 volt, go to step 14 .
Check terminal contact at PCM connector C2. Repair as necessary. If terminal contact is okay, go to step 19 .
Turn ignition off. Reconnect PCM harness connector C2. Disconnect fuel rail harness connector. Turn ignition on. Check voltage between injector harness terminal "T" and ground. If voltage reading is less than 10 volts, go to next step. If voltage reading is 10 volts or greater, go to step 15 .
Disconnect injector No. 5 harness connector. Check resistance between injector terminal "A" and ground. If resistance is greater than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, go to step 16 .
Check resistance between injector terminals "A" and "B". If resistance is greater than 25 ohms, go to step 18 . If resistance is 25 ohms or less, go to step 17 .
Repair open in circuit between splice and injector No. 5.
Repair short to voltage between injector harness connector and PCM harness connector.
Repair open or short to ground in circuit between fuel rail connector and injector No. 5.
Repair short to ground in circuit between fuel rail connector and injector No. 5.
Repair open in circuit between fuel rail connector and injector No. 5.
Replace fuel injector.
Replace PCM. Program replacement PCM using required equipment.

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

ECM will enable an injector on intake stroke of each cylinder. Ignition voltage is supplied directly to fuel injectors. ECM controls each injector by grounding control circuit via an internal driver.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current cylinder No. 6. If counter is increasing, go to next step. If counter is not increasing, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect main fuel injector connector. Turn ignition on, with engine off. Using test light connected to battery voltage, probe injector No. 6 harness connector control circuit (ECM side). If test light illuminates, go to next step. If test light does not illuminate, go to step 6 .
Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. If test light illuminates, go to step 11 . If test light does not illuminate, go to next step.
Turn ignition on, with engine off. Using test light connected to ground, probe injector No. 6 harness connector control circuit (ECM side). If test light illuminates, go to step 12 . If test light does not illuminate, go to step 15 .
Crank engine. If test light blinks about once per second, go to step 8 . If test light does not blink about once per second, go to next step.
Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. Using DVOM, check harness continuity of injector No. 6 control circuit between main injector and ECM harness connectors. If continuity exists, go to step 14 . If continuity does not exist, go to step 10 .
Turn ignition off. Using a jumper wire, reconnect switched battery feed circuit in male half of main injector harness connector to switched battery feed circuit in female half of main injector harness connector. Using test light connected to ground, probe injector No. 6 harness connector control circuit (injector side). Turn ignition on, with engine off. If test light illuminates, go to step 13 . If test light does not illuminate, go to next step.
Check for poor connections and terminal tension at fuel injector harness connector or at main injector connector. Check injector control circuit for open, short to ground, or short to voltage between injector and main injector connector. Check for open in switched battery feed circuit between injector and wiring splice. Repair as necessary, and then go to step 16 . If connections, terminals and circuits are okay, go to step 13 .
Repair open or high resistance in injector control circuit. After repairs, go to step 16 .
Repair short to ground in injector control circuit. After repairs, go to step 16 .
Repair short to voltage in injector driver circuit. After repairs, go to step 16 .
Replace fuel injector. After replacing injector, go to step 16 .
Check for poor connections and terminal tension at ECM harness connector. Repair as necessary. After repairs, go to step 16 . If connections and terminals are okay, go to next step.
Replace ECM. New ECM must be programmed with theft deterrent module frequency code currently on vehicle. After replacing ECM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0206 is set, go to step 2 . If DTC P0206 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

For any test that requires probing ECM or component harness connectors, use Connector Test Adapter Kit (J-35616-A). This will prevent damage to harness connector terminals. Check for poor connections at ECM or at component. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connection.

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault.

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine running.
Incorrect voltage level being detected on an injector driver circuit.
Conditions present for at least 30 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor SPECIFIC DTC. If scan tool indicates that this DTC failed this ignition cycle, go to step 4 . If scan tool does not indicate that this DTC failed this ignition cycle, go to next step.
Turn ignition on, engine off. Using scan tool, review and record FAILURE RECORDS data. Operate vehicle in fail conditions parameter. If scan tool indicates that this DTC failed this ignition cycle, go to next step. If scan tool does not indicate that this DTC failed this ignition cycle, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using scan tool, enter OUTPUT DRIVER DATA menu. If scan tool indicates that cylinder No. 6 injector circuit is STUCK HIGH, go to step 6 . If scan tool does not indicate that cylinder No. 6 injector circuit is STUCK HIGH, go to next step.
If scan tool indicates that cylinder No. 6 injector circuit is STUCK LOW, go to step 10 . If scan tool does not indicate that cylinder No. 6 injector circuit is STUCK LOW, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect 10-pin fuel injector connector. Crank engine. While cranking engine, if scan tool indicates that cylinder No. 6 injector circuit is STUCK LOW, go to next step. If scan tool does not indicate that cylinder No. 6 injector circuit is STUCK LOW, go to step 9 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on, engine off. Check voltage between cylinder No. 6 fuel injector control circuit and ground. If voltage reading is battery voltage, go to next step. If voltage reading is not battery voltage, go to step 15 .
Locate and repair short to voltage in cylinder No. 6 fuel injector control circuit. After repairs, go to step 16 .
If scan tool indicates that No. 6 injector control circuit is STUCK LOW, check affected fuel injector. See appropriate SYSTEM & COMPONENT TESTING article.
Disconnect 10-pin fuel injector harness connector. Using a test light connected to battery voltage, probe injector No. 6 control circuit at PCM side of 10-pin connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
Disconnect PCM harness connector. Using a test light connected to battery voltage, probe injector No. 6 control circuit at PCM connector. If test light illuminates, go to step 14 . If test light does not illuminate, go to step 15 .
With test light still connected, crank engine. If test light flashes, check affected fuel injector. See appropriate SYSTEM & COMPONENT TESTING article. If test light does not flash, go to next step.
Check cylinder No. 6 injector driver circuit between 10-pin injector connector and PCM for an open circuit. Repair as necessary. After repairs, go to step 16 .
Locate and repair short to ground in fuel injector driver circuit between PCM and 10-pin injector connector. After repairs, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle with the FAILURE RECORDS conditions. Check for DTCs. If this DTC is set, go to step 2 . If this DTC is not set, system is okay.

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.5L "W" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Ignition voltage is supplied directly to fuel injectors. PCM controls each fuel injector by grounding the control circuit through the internal solid state device called the driver.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor misfire current cylinder No. 5. If scan tool continuously indicates OK, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If scan tool does not continuously indicate OK, go to next step
If the entire bank of cylinders are inoperative, go to next step. If only some of the cylinders are inoperative, go to step 6 .
Check fuel injector fuses. If fuses are okay, go to next step. If fuses are not okay, go to step 11 .
Turn ignition off. Disconnect harness connector to affected fuel injector(s). Turn ignition on, engine off. Using a DVOM, check voltage between ground and ignition feed circuit in fuel injector harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 12 .
Using an Injector Test Light (J-34730-405), connect injector test light to injector harness connector. Crank engine. If engine starts, turn engine off after verifying test light. Repeat test on all affected injectors. If test light flashed on all of the injectors tested, go to step 18 . If test light did not flash on all or any of the injectors tested, go to next step.
Turn ignition off. Disconnect PCM harness connector. Using DVOM, check harness continuity of injector No. 5 control circuit between injector and PCM harness connectors. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 13 .
Check continuity between injector control circuit and ground. If resistance is infinite, go to next step. If resistance is not infinite, go to step 14 .
Turn ignition on, with engine off. Using DVOM, check for short to voltage in injector control circuit. If circuit is shorted to voltage, go to step 15 . If circuit is not shorted to voltage, go to next step.
Turn ignition off. Disconnect all fuel injector harness connectors. Using DVOM, check continuity between injector control circuits. If resistance is infinite, go to step 20 . If resistance is not infinite, go to step 16 .
Check for short to ground in injector ignition feed circuit. Repair as necessary. After repairs, go to step 22 . If circuit is okay, go to step 17 .
Repair open/high resistance in ignition feed circuit. After repairs, go to step 22 .
Repair open/high resistance in injector control circuit. After replacing injector, go to step 22 .
Repair injector control circuit that is shorted to ground. After repairs, go to step 22 .
Repair injector control circuit that is shorted to power. After repairs, go to step 22 .
Repair injector control circuits that are shorted together. After repairs, go to step 22 .
Test fuel injector coil. See appropriate SYSTEM & COMPONENT TESTING article. After testing fuel injector, go to step 22 .
Check for poor terminal connection at fuel injector harness connector. Repair as necessary. After repairs, go to step 22 . If connectors are okay, go to next step.
Replace fuel injector. After replacing fuel injector, go to step 22 .
Check for poor terminal connection at PCM harness connector. Repair as necessary. After repairs, go to step 22 . If connectors are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle within the conditions for setting this DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicates that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, review CAPTURED INFO. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault.

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine running.
Incorrect voltage level being detected on an injector driver circuit.
Conditions present for at least 30 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor SPECIFIC DTC. If scan tool indicates that this DTC failed this ignition cycle, go to step 4 . If scan tool does not indicate that this DTC failed this ignition cycle, go to next step.
Turn ignition on, engine off. Using scan tool, review and record FAILURE RECORDS data. Operate vehicle in fail conditions parameter. If scan tool indicates that this DTC failed this ignition cycle, go to next step. If scan tool does not indicate that this DTC failed this ignition cycle, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on, engine off. Check voltage between cylinder No. 6 fuel injector control circuit and ground. If voltage reading is battery voltage, go to next step. If voltage reading is not battery voltage, go to step 9 .
Check fuel injectors. See appropriate SYSTEM & COMPONENT TESTING article. If injectors are okay, go to next step. If injectors are not okay, go to step 17 .
Turn ignition off. Disconnect cylinder No. 6 injector connector. Turn ignition on. Check voltage between ground and fuel injector No. 6 control circuit at PCM connector. If voltage reading is zero volts, go to next step. If voltage reading is not zero volts, go to step 16 .
Check for intermittent open in ignition feed circuit in harness between fuse and injector No. 6. Check for intermittent open in injector No. 6 control circuit between PCM and injector. Repair as necessary. After repairs, go to step 19 . If circuits are okay, go to next step.
Check for poor terminal connections at fuel injector No. 6 connector and injector No. 6 connection at PCM connector. Repair as necessary. After repairs, go to step 19 . If connections are okay, go to step 18 .
Turn ignition off. Disconnect injector No. 6 connector. Turn ignition on. Check voltage between ground and ignition feed circuit at injector No. 6 connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 14 .
Using a test light connected to battery voltage, probe test light to injector No. 6 control circuit. If test light illuminates, go to step 15 . If test light does not illuminate, go to next step.
Turn ignition off. Using a fused jumper wire, jumper injector No. 6 control circuit and ignition feed circuit at injector connector. Turn ignition on. Using test light connected to ground, probe injector No. 6 control circuit at PCM connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 13 .
Check for poor terminal contact at injector No. 6 connector. Repair as necessary. After repairs, go to step 19 . If connection is okay, go to step 17 .
Locate and repair open in injector No. 6 control circuit. After repairs, go to step 19 .
Locate and repair open or short to ground in injector No. 6 ignition feed circuit. After repairs, go to step 19 .
Locate and repair short to ground in injector No. 6 control circuit. After repairs, go to step 19 .
Locate and repair short to voltage in injector No. 6 control circuit. After repairs, go to step 19 .
Replace faulty injector. After replacing injector, go to step 19 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle with the FAILURE RECORDS conditions. Check for DTCs. If this DTC is set, repeat step 2 . If this DTC is not set, system is okay.

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0560 and P1376 not set.
Ignition voltage 10-16 volts.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on. Using scan tool, check if DTCs P0201, P0204 and P0207 are also present. If these DTCs are present, diagnose using DTC P0201 test. If these DTCs are not present, go to next step.
Using scan tool, select DTC INFO then LAST TST. FAIL mode. If this DTC failed its last test, go to step 5 . If this DTC does not show that it failed its last test, go to next step.
Clear DTCs and operate vehicle until DTC P0206 resets. If DTC P0206 resets, go to next step. If DTC P0206 does not reset, fault is not present.
Turn ignition off. Disconnect injector No. 6 harness connector. Turn ignition on. Check voltage between injector No. 6 harness connector terminal "A" and ground. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 13 .
Reconnect injector No. 6 harness connector. Store fluid life reading as indicated on scan tool. Turn ignition off for 30 seconds, then disconnect PCM harness connector C2. Turn ignition on. Check voltage between PCM harness connector C2 terminal No. 18 and ground. If voltage reading is greater than 10 volts, go to next step. If voltage reading is not greater than 10 volts, go to step 10 .
Disconnect injector No. 6 harness connector. Check resistance between injector terminals "A" and "B". If resistance is greater than 8 ohms, go to next step. If resistance is not greater than 8 ohms, go to step 18 .
Check voltage between injector No. 6 harness connector terminal "B". If voltage reading is 0.1 volt or less, go to next step. If voltage reading is not 0.1 volt or less, go to step 14 .
Check terminal contact at PCM connector C2. Repair as necessary. If terminal contact is okay, go to step 19 .
Turn ignition off. Reconnect PCM connector C2. Disconnect fuel rail harness connector. Turn ignition on. Check voltage between injector harness terminal "U" and ground. If voltage reading is less than 10 volts, go to next step. If voltage reading is not less than 10 volts, go to step 15 .
Disconnect injector No. 6 harness connector. Check resistance between injector terminal "A" and ground. If resistance is greater than 10,000 ohms, go to next step. If resistance is not greater than 10,000 ohms, go to step 16 .
Check resistance between injector terminals "A" and "B". If resistance is greater than 25 ohms, go to step 18 . If resistance is not greater than 25 ohms, go to step 17 .
Repair open in circuit between splice and injector No. 6.
Repair short to voltage between injector harness connector and PCM harness connector.
Repair open or short to ground in circuit between fuel rail connector and injector No. 6.
Repair short to ground in circuit between fuel rail connector and injector No. 6.
Repair open in circuit between fuel rail connector and injector No. 6.
Replace fuel injector.
Replace PCM. Program replacement PCM using required equipment.

DTC P0207: INJECTOR NO. 7 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0560 and P1376 not set.
Ignition voltage 10-16 volts.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on. Using scan tool, check if DTCs P0201, P0204 and P0206 are also present. If these DTCs are present, diagnose using DTC P0201 test. If these DTCs are not present, go to next step.
Using scan tool, select DTC INFO then LAST TST. FAIL mode. If this DTC failed its last test, go to step 5 . If this DTC does not show that it failed its last test, go to next step.
Clear DTCs and operate vehicle until DTC P0207 resets. If DTC P0207 resets, go to next step. If DTC P0207 does not reset, fault is not present.
Turn ignition off. Disconnect injector No. 7 harness connector. Turn ignition on. Check voltage between injector No. 7 harness connector terminal "A" and ground. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 13 .
Reconnect injector No. 7 harness connector. Store fluid life reading as indicated on scan tool. Turn ignition off for 30 seconds, then disconnect PCM harness connector C2. Turn ignition on. Check voltage between PCM harness connector C2 terminal No. 11 and ground. If voltage reading is greater than 10 volts, go to next step. If voltage reading is not greater than 10 volts, go to step 10 .
Disconnect injector No. 7 harness connector. Check resistance between injector terminals "A" and "B". If resistance is greater than 8 ohms, go to next step. If resistance is not greater than 8 ohms, go to step 18 .
Check voltage between injector No. 7 harness connector terminal "B". If voltage reading is 0.1 volt or less, go to next step. If voltage reading is not 0.1 volt or less, go to step 14 .
Check terminal contact at PCM connector C2. Repair as necessary. If terminal contact is okay, go to step 19 .
Turn ignition off. Reconnect PCM harness connector C2. Disconnect fuel rail harness connector. Turn ignition on. Check voltage between injector harness terminal "C" and ground. If voltage reading is less than 10 volts, go to next step. If voltage reading is not less than 10 volts, go to step 15 .
Disconnect injector No. 7 harness connector. Check resistance between injector terminal "A" and ground. If resistance is greater than 10,000 ohms, go to next step. If resistance is not greater than 10,000 ohms, go to step 16 .
Check resistance between injector terminals "A" and "B". If resistance is greater than 25 ohms, go to step 18 . If resistance is not greater than 25 ohms, go to step 17 .
Repair open in circuit between splice and injector No. 7.
Repair short to voltage between injector harness connector and PCM harness connector.
Repair open or short to ground in circuit between fuel rail connector and injector No. 7.
Repair short to ground in circuit between fuel rail connector and injector No. 7.
Repair open in circuit between fuel rail connector and injector No. 7.
Replace fuel injector.
Replace PCM. Program replacement PCM using required equipment.

DTC P0208: INJECTOR NO. 8 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0560 and P1376 not set.
Ignition voltage 10-16 volts.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on. Using scan tool, check if DTCs P0202, P0203 and P0205 are also present. If these DTCs are present, diagnose using DTC P0202 test. If these DTCs are not present, go to next step.
Using scan tool, select DTC INFO then LAST TST. FAIL mode. If this DTC failed its last test, go to step 5 . If this DTC does not show that it failed its last test, go to next step.
Clear DTCs and operate vehicle until DTC P0208 resets. If DTC P0208 resets, go to next step. If DTC P0208 does not reset, fault is not present.
Turn ignition off. Disconnect injector No. 8 harness connector. Turn ignition on. Check voltage between injector No. 8 harness connector terminal "A" and ground. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 13 .
Reconnect injector No. 8 harness connector. Store fluid life reading as indicated on scan tool. Turn ignition off. Wait 30 seconds, then disconnect PCM harness connector C2. Turn ignition on. Check voltage between PCM harness connector C2 terminal No. 22 and ground. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 10 .
Disconnect injector No. 8 harness connector. Check resistance between injector harness connector terminals "A" and "B". If resistance is greater than 8 ohms, go to next step. If resistance is not greater than 8 ohms, go to step 18 .
Check voltage between injector No. 8 harness connector terminal "B". If voltage reading is 0.1 volt or less, go to next step. If voltage reading is not 0.1 volt or less, go to step 14 .
Check terminal contact at PCM connector C2. Repair as necessary. If terminal contact is okay, go to step 19 .
Turn ignition off. Reconnect PCM harness connector C2. Disconnect fuel rail harness connector. Turn ignition on. Check voltage between injector harness terminal "V" and ground. If voltage reading is less than 10 volts, go to next step. If voltage reading is not less than 10 volts, go to step 15 .
Disconnect injector No. 8 harness connector. Check resistance between injector terminal "A" and ground. If resistance is greater than 10,000 ohms, go to next step. If resistance is not greater than 10,000 ohms, go to step 16 .
Check resistance between injector terminals "A" and "B". If resistance is greater than 25 ohms, go to step 18 . If resistance is not greater than 25 ohms, go to step 17 .
Repair open in circuit between splice and injector No. 8.
Repair short to voltage between injector harness connector and PCM harness connector.
Repair open or short to ground in circuit between fuel rail connector and injector No. 8.
Repair short to ground in circuit between fuel rail connector and injector No. 8.
Repair open in circuit between fuel rail connector and injector No. 8.
Replace fuel injector.
Replace PCM. Program replacement PCM using required equipment.

The HOT light or the LOW COOLANT light will illuminate if DTC P0217 or P0218 is present. The light will illuminate and stay on steady for either of these conditions. If PCM detects a low coolant condition (P1620) the light will flash as opposed to staying on steady.

DTC P0217 will set if engine coolant temperature is greater than 244°F (118°C), and no other ECT related DTCs are present.

DTC P0218 will set if transaxle fluid temperature is greater than 284°F (140°C), actuator temperature is greater than 320°F (160°C) as calculated by PCM from fluid temperature and actuator on time, and if no other transaxle temperature related DTCs are present.

If warning light is flashing, refer to DTC P1620 for diagnosis. Engine coolant and/or transaxle temperature that is too high can be caused by trailer towing, restricted transaxle oil cooler or lines, restricted radiator or condenser air flow, missing or damaged front air dam, low transaxle fluid level, inoperative cooling fan, corrosion at ECT sensor connectors, faulty water pump or thermostat, or faulty ECT sensor. A/C will not operate when coolant temperature reaches 244°F (118°C) to prevent engine damage.

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Fuel pump relay coil is supplied power via main relay (switched battery feed). ECM controls relay by grounding control circuit via an internal driver.

When ECM detects reference pulses from Crankshaft Position (CKP) sensor, ECM will enable fuel pump. Relay is used to control high current flow to fuel pump. This allows ECM driver to only have to handle relatively low current used by relay. DTC will set when a short to ground, open, or short to battery voltage is detected on control circuit.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Check fuel pump fuse No. 18 (20-amp), located in fuse block. If fuse is open, replace fuse and go to step 15 . If fuse is okay, go to next step.
Turn ignition on, with engine off. Using scan tool, command fuel pump relay on and off. If relay turns on and off with each command, go to next step. If relay does not turn on and off with each command, go to step 6 .
Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. Jumper main relay control circuit to ground. Using DVOM on 10-amp scale, measure current between ground and relay control circuit at ECM harness connector, for 2 minutes. If current draw is 0.10-0.75 amp, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If current draw is not 0.10-0.75 amp, go to next step.
Turn ignition off. Disconnect fuel pump relay connector. Using DVOM, measure resistance between ground and relay control circuit at ECM harness connector. If resistance is infinite, go to step 12 . If resistance is not infinite, go to step 10 .
Turn ignition off. Disconnect fuel pump relay connector. Connect test light between relay coil terminals at harness connector. Turn ignition on. Using scan tool, command fuel pump relay on and off. If test light turns on and off with each command, go to step 9 . If test light does not turn on and off with each command, go to next step.
With test light connected to ground, probe relay harness connector switched battery feed circuit. If test light is on, go to next step. If test light is off, go to step 11 .
Turn ignition off. Reconnect fuel pump relay. Disconnect ECM harness connector. Jumper main relay control circuit to ground. With fused jumper wire connected to ground, probe fuel pump relay control circuit at ECM harness connector. If relay operates, go to step 13 . If relay does not operate, go to step 10 .
Check for poor connections at relay. Repair as necessary. After repairs, go to step 15 . If connections are okay, go to step 12 .
Repair relay control circuit. After repairs, go to step 15 .
Repair switched battery feed circuit to relay. After repairs, go to step 15 .
Replace relay. After replacing relay, go to step 15 .
Check for poor connections and terminal tension at ECM harness connector. Repair as necessary. After repairs, go to step 15 . If connections and terminals are okay, go to next step.
Replace ECM. New ECM must be programmed with theft deterrent module frequency code currently on vehicle. After replacing ECM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0230 is set, go to step 3 . If DTC P0230 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault.

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Fuel pump is powered by fuel pump relay. PCM energizes fuel pump relay at ignition on for 2-3 seconds. Fuel pump will remain on for as long as PCM receives reference pulse from electronic ignition system. Conditions for setting DTC

Ignition is on.
PCM detects an electrical malfunction on fuel pump relay control circuit.
Conditions met for 0.5 second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Connect a test light between fuel pump relay connector cavities for fuel pump relay control circuit and relay ground. Install scan tool. Turn ignition on, with engine off. Using scan tool, command fuel pump relay on and off. If test light illuminates when fuel pump is commanded on, go to step 7 . If test light does not illuminate when fuel pump is commanded on, go to next step.
Turn ignition off. Disconnect PCM harness connector. Using test light connected to battery voltage, probe fuel pump relay control circuit at PCM connector. If test light illuminates, go to step 9 . If test light does not illuminate, go to next step.
Using test light connected to battery voltage, probe fuel pump relay ground circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 10 .
Check for open in fuel pump relay control circuit between PCM and fuel pump relay. Repair as necessary. After repairs, go to step 14 . If circuit is okay, go to next step.
Check fuel pump relay control circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 14 . If circuit is okay, go to step 12 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on, with engine off. Using test light connected to ground, probe fuel pump relay control circuit at PCM connector. If test light illuminates, go to step 13 . If test light does not illuminate, go to next step.
Check for poor terminal connection at fuel pump relay connector. Repair as necessary. After repairs, go to step 14 . If connections are okay, go to step 11 .
Locate and repair short to ground in fuel pump relay ground circuit. After repairs, go to step 14 .
Locate and repair open in fuel pump relay ground circuit. After repairs, go to step 14 .
Replace fuel pump relay. After replacing relay, go to step 14 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 14 .
Locate and repair short to voltage in fuel pump control circuit. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .

Scan tool will appear not to run if diagnostic passes. Using FREEZE FRAME and/or FAILURE RECORDS may aid in locating an intermittent condition. An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside of insulation. Check for poor connections at PCM or fuel pump relay.

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.5L "W" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

The PCM provides ignition voltage to control fuel pump relay. PCM has the ability to detect electrical malfunction on relay control circuit. When ignition switch is first turned on, PCM energizes fuel pump relay which then applies power to fuel pump. Relay will remain on as long as engine is running or cranking and the PCM is receiving reference pulses.

If no reference pulses are present, PCM de-energizes fuel pump relay within 2 seconds after ignition is turned on or engine is stopped. Fuel pump can be activated by using scan tool's output controls function, even with engine off.

DTC will set when PCM detects an electrical malfunction on fuel pump relay control circuit and condition is present for 0.5 second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition off. Wait 15 seconds, then turn ignition on, with engine off. Listen for fuel pump operation. Fuel pump should operate for 2 seconds. Fuel pump can also be commanded on using scan tool. If fuel pump turns on and off, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If fuel pump does not turn on and off, go to next step.
If fuel pump stays on all the time, go to step 9 . If fuel pump does not stay on all the time, go to next step.
Using a test light, connect test light between fuel pump relay connector cavities for the control and ground circuit. Using scan tool, select fuel pump output control function and command fuel pump on. Observe test light. If test light illuminates when fuel pump is commanded on, go to step 10 . If test light does not illuminate when fuel pump is commanded on, go to next step.
Connect test light between battery voltage and fuel pump relay ground circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
Turn ignition off. Disconnect PCM harness connector. Using test light connected to battery voltage, probe test light to fuel pump relay control circuit at PCM harness connector side. If test light illuminates, go to step 11 . If test light does not illuminate, go to next step.
Check for open in fuel pump relay control circuit between PCM and fuel pump relay. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to next step.
Check fuel pump relay control circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 16 . If connections are okay, go to step 15 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on. Observe fuel pump. If fuel pump is running, go to step 13 . If fuel pump is not running, go to step 15 .
Check for poor terminal connection at fuel pump relay. Repair as necessary. After repairs, go to step 16 . If terminal connection is okay, go to step 14 .
Locate and repair short to ground in fuel pump relay control circuit. After repairs, go to step 16 .
Locate and repair open in fuel pump relay ground circuit. After repairs, go to step 16 .
Locate and repair short to voltage in fuel pump relay control circuit. After repairs, go to next step 16 .
Replace fuel pump relay. After replacing relay, go to step 16 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, go to step 2 .
Using scan tool, select CAPTURE INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault.

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

PCM provides ignition voltage to control fuel pump. PCM has ability to detect an electrical malfunction on relay control circuit. When ignition is first turned on, PCM energizes fuel pump relay which applies power to fuel pump. Fuel pump relay will remain on as long engine is running or cranking and PCM is receiving reference pulses.

If no reference pulses are present, PCM de-energizes fuel pump relay within 2 seconds after ignition is turned on or engine is stopped. With engine off/stopped, fuel pump can be turned on by using scan tool output controls function. If electrical malfunction is detected, DTC will set. Conditions for setting DTC

Ignition is on.
PCM detects an electrical malfunction on fuel pump relay control circuit.
Conditions met for 0.5 second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Disconnect fuel pump relay. Connect a test light between fuel pump relay connector cavities for fuel pump relay control circuit and relay ground. Install scan tool. Turn ignition on, with engine off. Using scan tool, command fuel pump relay on and off. If test light illuminates when fuel pump is commanded on, go to step 7 . If test light does not illuminate when fuel pump is commanded on, go to next step.
Turn ignition off. Disconnect PCM harness connector. Using a test light connected to battery voltage, probe fuel pump relay control circuit at PCM connector. If test light illuminates, go to step 9 . If test light does not illuminate, go to next step.
Using test light connected to battery voltage, probe fuel pump relay ground circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 10 .
Check for open in fuel pump relay control circuit between PCM and fuel pump relay. Repair as necessary. After repairs, go to step 14 . If circuit is okay, go to next step.
Check fuel pump relay control circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 14 . If circuit is okay, go to step 12 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on, with engine off. Using test light connected to ground, probe fuel pump relay control circuit at PCM connector. If test light illuminates, go to step 13 . If test light does not illuminate, go to next step.
Check for poor terminal connection at fuel pump relay connector. Repair as necessary. After repairs, go to step 14 . If connections are okay, go to step 11 .
Locate and repair short to ground in fuel pump relay ground circuit. After repairs, go to step 14 .
Locate and repair open in fuel pump relay ground circuit. After repairs, go to step 14 .
Replace fuel pump relay. After replacing relay, go to step 14 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 14 .
Locate and repair short to voltage in fuel pump control circuit. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .

DTC P0230: FUEL PUMP CONTROL CIRCUIT (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Conditions for running this DTC are: engine speed is greater than 600 RPM, system voltage is 6-18 volts, PCM determines that fuel pump driver commanded state and actual state do not match, and all these conditions are present for at least 2.5 seconds.

DTC will set when PCM detects that the commanded state of the driver and actual state of the control circuit do not match for a minimum of 2.5 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Install scan tool. Turn ignition on, with engine off. Using scan tool, command fuel pump relay on and off. If fuel pump relay turns on and off as commanded, go to next step. If fuel pump relay does not turn on and off as commanded, go to step 5 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on. Using DVOM on 10-amp scale, check current between battery positive and PCM harness connector, fuel pump relay control circuit. If DVOM reading is less than 0.75 amp (but not zero), see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If DVOM reading is not less than 0.75 amp, go to next step.
Turn ignition off. Remove fuel pump relay. Using DVOM, check resistance between ground and fuel pump relay control circuit at PCM harness connector. If resistance is infinite, go to step 11 . If resistance is not infinite, go to step 10 .
Turn ignition off. Remove fuel pump relay. Connect a test light between fuel pump relay ground circuit and control circuit terminals at engine compartment fuse/relay block. Turn ignition on, with engine off. Using scan tool, command fuel pump relay on and off. If test light turns on and off as commanded, go to step 8 . If test light does not turn on, go to next step.
Connect test light between battery positive and fuel pump relay ground circuit terminal at engine compartment fuse/relay block. If test light illuminates, go to next step. If test light does not illuminate, go to step 9 .
Turn ignition off. Install fuel pump relay. Disconnect PCM harness connector. Turn ignition on, with engine off. Connect a fused jumper wire between battery positive and fuel pump relay control circuit at PCM harness connector. If relay operates, go to step 12 . If relay does not operate, go to step 10 .
Check connections at fuel pump relay. Repair as necessary. After repairs, go to step 13 . If connections are okay, go to step 11 .
Repair open in fuel pump relay ground circuit. After repairs, go to step 13 .
Repair faulty relay control circuit as necessary. After repairs, go to step 13 .
Replace fuel pump relay. After replacing relay, go to step 13 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Attempt to start engine. If engine starts, go to next step. If engine does not start, go to step 2 .
Using scan tool, select CAPTURE INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Scan tool will appear to not run if diagnostic passes. Using FREEZE FRAME and/or FAILURE RECORDS may aid in locating an intermittent condition.

DTC P0230: FUEL PUMP CONTROL CIRCUIT (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine speed greater than 600 RPM.
System voltage is 6-16 volts.
PCM determines that fuel pump driver commanded state and actual state do not match.
Conditions met for at least 10 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Install scan tool. Turn ignition on, with engine off. Using scan tool, command fuel pump relay on and off. If fuel pump relay turns on and off as commanded, go to next step. If fuel pump relay does not turn on and off as commanded, go to step 5 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on. Using DVOM on 10-amp scale, check current between battery positive and PCM connector (harness side), fuel pump relay control circuit. If current is less than 0.75 amp (but not zero), see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If not, go to next step.
Turn ignition off. Remove fuel pump relay. Using DVOM, check resistance between ground and PCM connector (harness side), fuel pump relay control circuit. If resistance is infinite, go to step 11 . If resistance is not infinite, go to step 10 .
Turn ignition off. Remove fuel pump relay. Connect a test light between fuel pump relay connector terminals No. 85 and 86. Turn ignition on. Using scan tool, command fuel pump relay on and off. If test light turns on and off as commanded, go to step 8 . If test light does not turn on, go to step 7 .
Check resistance between fuel pump ground circuit at underhood relay block to battery ground. If resistance is 0-5 ohms, go to next step. If resistance is not 0-5 ohms, go to step 9 .
Turn ignition off. Install fuel pump relay. Disconnect PCM harness connector. Turn ignition on, engine off. Connect a fused jumper wire between battery positive and PCM connector (harness side), fuel pump relay control circuit. If relay operates, go to step 12 . If relay does not operate, go to step 10 .
Check connections at fuel pump relay. Repair as necessary. After repairs, go to step 13 . If connections are okay, go to step 11 .
Repair open in fuel pump relay ground circuit. After repairs, go to step 13 .
Repair faulty relay control circuit as necessary. After repairs, go to step 13 .
Replace fuel pump relay. After replacing relay, go to step 13 .
Replace PCM. Program replacement PCM using required equipment. After repair is completed, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0230. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Scan tool will appear to not run if diagnostic passes. Using FREEZE FRAME and/or FAILURE RECORDS may aid in locating an intermittent condition.

DTC P0231: FUEL PUMP FEEDBACK CIRCUIT-LOW VOLTAGE (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Fuel pump is powered by fuel pump relay. PCM energizes the fuel pump relay for 2 seconds at ignition on, to provide fuel pressure for starting. After the 2 second fuel pump prime, PCM will not power fuel pump until 4X reference pulses are received, indicating that the engine is cranking or running. PCM monitors voltage in the fuel pump feedback circuit to select fuel pump voltage supply faults. DTC will set when PCM sees the fuel pump is not energized (2 volts or less on feedback) with engine cranking or running.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition off. Turn ignition on for 5 seconds. After 5 seconds, attempt to start engine. If engine starts and runs, go to next step. If engine does not start or starts but dies, go to step 7 .
Using scan tool, note DTC status condition. If DTC failed in this ignition cycle, go to next step. If DTC did not fail in this ignition cycle, fault is not present. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
With engine still running, note FP. VOLT FEEDBACK on scan tool. If voltage reading is greater than 2 volts, go to step 25 . If voltage reading is not greater than 2 volts, go to next step.
Store fluid life as indicated on scan tool. Turn ignition off and wait 30 seconds, then removed fuel pump relay. Disconnect PCM harness connector C1. Using DVOM, check resistance between fuel pump relay harness connector terminal No. 87 and fuel pump feedback circuit at PCM harness connector. If resistance is 5 ohms or less, go to step 25 . If resistance is not 5 ohms or less, go to next step.
Repair open in circuit between PCM and splice or check for poor terminal contact at PCM connector C1.
Check fuel pump fuse, located in rear fuse block. If fuse is okay, go to next step. If fuse is faulty, go to step 18 .
Remove fuel pump relay. Turn ignition on. Using DVOM, check voltage to ground at relay harness connector terminal No. 30. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 23 .
Check voltage between fuel pump harness connector terminals No. 30 and No. 86. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 24 .
Connect a jumper between fuel pump harness connector terminals No. 30 and 87. If fuel pump operates, go to next step. If fuel pump does not operate, go to step 15 .
Turn ignition off. Connect DVOM between fuel pump relay harness connector terminals No. 85 and No. 86. Wait 10 seconds, then turn ignition on and check voltage reading within 2 seconds after turning on ignition. If voltage reading is 10 volts or greater, go to next step. If voltage reading is not 10 volts or greater, go to step 13 .
Replace fuel pump relay.
Store fluid life as indicated on scan tool. Turn ignition off for 30 seconds, then disconnect PCM harness connector C2. Using DVOM, check resistance between fuel pump relay control circuit at PCM harness connector and relay harness connector terminal No. 85. If resistance is 5 ohms or less, go to step 25 . If resistance is not 5 ohms or less, go to next step.
Repair open in circuit between PCM harness connector and relay harness connector.
Using scan tool, note FP. VOLT FEEDBACK reading. If scan tool reading is 10 volts or greater, go to next step. If scan tool reading is not 10 volts or greater, go to step 17 .
Check for open in circuit between fuel pump and splice. Repair as necessary. If circuit is okay, go to step 22 .
Check for open in circuit between fuel pump and splice.
Turn ignition off. Remove fuel pump relay. Using DVOM, check resistance between fuel pump harness connector terminal No. 30 and ground. If resistance is 2 ohms or greater, go to step 20 . If resistance is not 2 ohms or greater, go to next step.
Repair short to ground between fuel pump fuse and relay.
Store fluid life as indicated on scan tool. Turn ignition off. Wait 30 seconds, then disconnect PCM harness connector C1. Disconnect fuel pump connector. Check resistance to ground at fuel pump relay harness connector terminal No. 87. If resistance is greater than 2 ohms, go to step 22 . If resistance is not greater than 2 ohms, go to next step.
Repair short to ground between PCM connector C1, fuel pump connector, fuel pump relay or a shorted fuel pump.
Check fuel pump ground circuit for cause of no-start condition. If ground circuit is okay, perform basic fuel pressure check.
Repair open in circuit between fuse and relay.
Repair open in ground circuit. If circuit is okay, check for poor ground connection.
Check terminal contact at PCM connector C1 fuel pump feedback circuit and PCM connector C2 fuel pump relay control circuit. Repair as necessary. If terminal contact is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment.

If DTC sets without a driveability complaint, check for open circuit between splice and PCM or poor PCM terminal contact. If a complaint did not exist, check for poor relay contact, relay ground, etc.

DTC P0232: FUEL PUMP FEEDBACK CIRCUIT-HIGH VOLTAGE (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0117, P0118 and P0322 not set.
Coolant temperature at 122°F (50°C) or greater.
No reference pulses detected since key on.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on for 15 seconds. Using scan tool, note FP. VOLT FEEDBACK reading. If voltage reading is greater than 7 volts, go to next step. If voltage reading is not greater than 7 volts, fault is not present.
Remove fuel pump relay. If voltage reading is greater than 7 volts, go to next step. If voltage reading is not greater than 7 volts, go to step 6 .
Store fluid life as indicated on scan tool. Turn ignition off and wait 30 seconds, then disconnect PCM harness connector C1. Turn ignition on. Check voltage to ground at PCM harness connector C1 fuel pump feedback circuit. If voltage reading is 7 volts or less, go to step 11 . If voltage reading is not 7 volts or less, go to next step.
Check for loose or poor fuel pump ground connection. Repair as necessary. If ground connection is okay, go to step 8 .
Turn ignition off. Wait 10 seconds. Using DVOM, check voltage between fuel pump relay harness connector terminals No. 85 and 86. Turn ignition on and note DVOM reading. If voltage reading remains at 12 volts for 10 seconds, go to next step. If voltage reading does not stay at 12 volts for 10 seconds, go to step 9 .
Store fluid life as indicated on scan tool. Turn ignition off and wait 30 seconds. Disconnect PCM connector C2. Turn ignition on. Check voltage between ground and PCM harness connector fuel pump relay control circuit. If voltage reading is greater than zero volts, go to step 10 . If voltage reading is not greater than zero volts, go to step 11 .
Repair short to voltage in fuel pump feedback circuit.
Replace fuel pump.
Repair short to voltage in fuel pump relay control circuit.
Check terminal contact at PCM harness connector C1 fuel pump feedback circuit. Repair as necessary. If terminal contact is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment.

DTC could set due to sluggish or intermittently stuck fuel pump relay.

DTC P0243: SUPERCHARGER BOOST SOLENOID CONTROL CIRCUIT (3.8L "C", "G" & "W" BODIES - VIN 1)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

PCM uses an output driver module to control ground (control) circuit to boost control solenoid. Output driver module is also used by PCM to diagnose the output of this circuit. If an improper voltage level has been detected on supercharger boost control solenoid control circuit for 30 seconds or more, DTC will set. For duplication of DTC, ensure ignition is on.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Measure voltage between ground and boost control solenoid control circuit at PCM harness connector. If voltage is near battery voltage, go to next step. If voltage is not as specified, go to step 6 .
Using DVOM set to measure current, monitor current for 2 minutes between ground and boost control solenoid control circuit at PCM harness connector. If current remains 0.05-0.08 amps, go to step 11 . If current does not remain 0.05-0.08 amps, go to next step.
Turn ignition off. Disconnect boost control solenoid. Turn ignition on. Check for voltage between ground and boost control solenoid control circuit. If voltage is not present, go to step 10 . If voltage is present, go to next step.
Repair short to voltage in boost control solenoid control circuit. After repairs, go to step 16 .
Turn ignition off. Check fuse supplying ignition voltage to boost control solenoid. If fuse is open, go to next step. If fuse is okay, go to step 8 .
Repair short to ground in ignition feed circuit to boost control solenoid. After repairs, go to step 16 .
Disconnect boost control solenoid. Turn ignition on. Measure voltage between ground and boost control solenoid ignition feed circuit. If voltage is near battery voltage, go to next step. If voltage is not as specified, go to step 13 .
Check boost control solenoid control circuit for an open or short to ground. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to next step.
Check boost control solenoid control circuit for poor connections at PCM and solenoid. Check boost control solenoid ignition feed circuit for poor connection at solenoid. Repair as necessary. After repairs, go to step 16 . If connections are okay, go to step 14 .
Turn ignition off. Reconnect PCM. Disconnect boost control solenoid. Turn ignition on. Connect test light between boost control solenoid control circuit and ignition feed circuit at harness connector. Using scan tool, command boost control solenoid on and off. If test light flashes, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If test light does not flash, go to next step.
Check boost control solenoid control circuit for poor connection at PCM. Repair as necessary. After repairs, go to step 16 . If connection is okay, go to step 15 .
Repair open in ignition feed circuit to boost control solenoid. After repairs, go to step 16 .
Replace boost control solenoid. After repairs, go to step 16 .
Replace PCM. Program replacement PCM using required equipment. After repairs, go to next step.
Using scan tool, review and record FAILURE RECORDS data. Clear DTCs. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, system is okay. If scan tool does not indicate that this test ran and passed, go to step 2 .

Check for damaged wiring harness. If harness appears to be okay, observe scan tool while moving related connectors and wiring harnesses. A change in scan tool display may help to locate fault. If sensor signal is only affected when harness is moved at component, and there is no problem with harness or connections, component may be faulty.

Using FREEZE FRAME and/or FAILURE RECORDS data mode may aid in locating an intermittent condition. If DTC cannot be duplicated, information included in FREEZE FRAME and/or FAILURE RECORDS data can be useful in determining how many miles since DTC set. FAIL COUNTER and PASS COUNTER can also be used to determine how many ignition cycles diagnostic reported a pass or a fail condition. To isolate when DTC failed, operate vehicle within same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.).

DTC P0300: RANDOM CYLINDER MISFIRE DETECTED (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

PCM uses pulses from the crankshaft position sensor to determine the position and RPM of the engine at various degrees of rotation. PCM can then base misfire diagnostics on the principle that crankshaft velocity will increase as each cylinder contributes its power input. Under certain conditions, the PCM will perform a series of tests to determine misfire percentage on a cylinder based on crankshaft velocity variation. The MIL will flash if an active catalyst damaging misfire occurs (20-100 percent) and will stay on steady if an emission related misfire (2-19 percent) is present after 2 consecutive trips. The MIL will turn off after 3 consecutive passed trips meeting the same misfire criteria or 80 passed trips if the criteria has not been met.

DTC will set if random misfires have been detected after a series of tests when engine speed is 469-7188 RPM, traction control fuel cut-off is not active, coolant temperature is 20-244°F (-7-118°C), throttle change is not rapid, not in decel fuel cut-off mode, ignition voltage is at 8-15 volts and no TP sensor, CKP, IAT, MAT or ECT DTCs have been set. Misfire diagnostics are continually checked with engine running when these conditions have been met.

Connect scan tool. Start engine and operate for one minute. Check if any active misfire DTCs are present. If DTCs are present, go to next step. If DTCs are not present, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If DTC P0300 is set with no other active injector fault or EI system DTC, go to next step. If other DTCs are present, diagnose affected DTCs first. Check for cause of misfire.
Check fuel grade and condition (i.e. water). Start engine and check for vacuum leaks or arching spark plug wires. Repair as necessary. If no vacuum leak or faulty spark plug wires are found, go to next step.
Using scan tool, note current misfire counts. Run engine for one minute. If misfire counts for cylinders No. 2 and 3 or cylinders No. 1 and 4 are dominant, go to next step. If counts on either cylinders are not dominant, go to step 7 .
Remove spark plus on misfiring cylinders. Check for spark using a spark tester. If spark is consistent, go to next step. If spark is not consistent, check coil secondary resistance. Resistance should be 700-10,000 ohms at 70°F (21°C). If resistance is not as specified, replace coil and retest engine. If resistance is as specified, check for problems in wires, coil pack or module. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . Also check for open or short in circuits to EI module terminals "C" and "E".
Perform compression test. Normal compression should be 185-205 psi (13-14 kg/cm 2 ). If compression is okay, replace spark plugs and retest engine. If compression is not okay, check for internal mechanical engine problem. Repair as necessary.
Perform fuel pressure test. Fuel pressure should be 38-44 psi (2.7-3.0 kg/cm 2 ). If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, diagnose fuel system. See appropriate SYSTEM & COMPONENT TESTING article.
Perform fuel pressure leak down test. Re-prime fuel rail and wait 5 minutes. Maximum leak down should be 3 psi (.2 kg/cm 2 ). If pressure is holding, go to next step. If pressure is not holding, check for leaking injector and/or fuel pressure regulator. Replace as necessary.
Perform fuel injector balance test. See appropriate SYSTEM & COMPONENT TESTING article. Prime fuel rail after each injector is tested. Note fuel pressure gauge drop. If pressure drop is consistent within 1.5 psi (.1 kg/cm 2 ), go to next step. If pressure drop is not consistent, check injector resistance. Resistance should be 12 ohms. If resistance is as specified, check for stuck injector pintle valve or clogged injector. Clean or replace injector. If injector resistance is not as specified, replace injector and retest engine.
Remove wires from spark plugs and test for spark on each cylinder. If spark is consistent on all cylinders, go to next step. If spark is not consistent, check for faulty wire, coil pack and/or module. Repair or replace as necessary. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Perform compression test on all cylinders. Normal compression should be 185-205 psi (13-14 kg/cm 2 ). If compression is okay, replace spark plugs and retest engine. If compression is not okay, check for internal mechanical engine problem. Repair as necessary.

When diagnosing an intermittent problem, use scan tool to review malfunction history diagnostic information. This data can be used to duplicate a problem. If an injector, EST or EGR DTC is active and a misfire is active, diagnose those problems first. Use scan tool to monitor active misfire counts. Spraying water on wires will find bad wire(s). The scan tool active misfire counts should pick up an intermittent misfire problem. Watch scan tool misfire counter. When a specific cylinder misfires under certain load, conditions may be duplicated in the shop. Use the following specifications to help in diagnosis

Injector Resistance - 12 Ohms
Wire Resistance - Less Than 12,000 Ohms
Coil Pack Resistance - 8000-15,000 Ohms (Tower-To-Tower)
Spark Plug Gap - 0.060 in.
Wire Position On Coil - 4-1-2-3

DTC P0300: ENGINE MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) monitors Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to detect if engine is misfiring. PCM looks for a sudden drop in crankshaft speed. This test is executed in blocks of 100 camshaft revolution tests. It may take several tests to set a DTC. Under light misfire conditions, it may take more than one trip to set a DTC. Severe misfire will flash Malfunction Indicator Light (MIL) indicating that catalytic converter damage is possible. Conditions for setting this DTC

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 or P1621 not set.
Misfire total is 12 counts or more.
Engine speed is 469-6406 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7-123°C).
Engine run time longer than 15 seconds.
TP sensor angle has not changed more than 8 percent in one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P0200 is also set, diagnose that DTC before proceeding. If DTC P0200 is not set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 31 . If no problems are found, go to next step.
Start and allow engine to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If any MISFIRE CURRENT counters are incrementing, go to next step. If any MISFIRE CURRENT counters are not incrementing, go step 6 .
If all counters are equal (within a percentage of each other), go to step 7 . If counters are not equal (within a percentage of each other), go to step 11 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If any of MISFIRE CURRENT counters are incrementing, go to step 5 . If MISFIRE CURRENT counters are not incrementing, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Install fuel pressure gauge. Start engine and allow it to idle. If fuel pressure is 41-47 psi (2.9-3.3 kg/cm 2 ), go to next step. If fuel pressure is not 41-47 psi (2.9-3.3 kg/cm 2 ), see BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Check for fuel contamination. If fuel is contaminated, go to step 10 . If fuel is not contaminated, go to next step.
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted airflow, etc.). Repair as necessary. After repairs, go to step 31 .
Replace contaminated fuel. After repairs, go to step 31 .
Turn ignition off. Disconnect fuel injector harness connector. Temporarily remove ignition coil and Ignition Control Module (ICM) assembly. Install Spark Plug Jumper Wires (J-36012). Install Spark Tester (J-26792) to spark plug jumper for each cylinder, one at a time. Disconnect spark plug boot from companion cylinder at ignition coil housing and install a jumper wire between ground and spark plug connector at ignition coil housing (1-4 or 2-3). Crank engine and check for spark. If spark is present at all cylinders, go to next step. If spark is not present at one or more cylinders, go to step 20 .
Check for faulty spark plugs. Replace defective spark plug(s) as necessary. After repairs, go to step 31 . If spark plugs are okay, go to next step.
Turn ignition off. Disconnect fuel injector connectors from injectors. Install an injector test light on injector harness connector for cylinders that had misfired. Crank engine and note test light. If injector test light blinks, go to next step. If injector test light does not blink, go to step 15 .
Perform fuel injector test. See appropriate SYSTEM & COMPONENT TESTING article. If injectors are okay, go to step 9 . If injectors are not okay, go to step 16 .
Disconnect injector test light. Using a standard test light connected to ground, probe ignition feed of injector harness connector for each affected/misfiring injector. Crank engine. If test light illuminates, go to step 17 . If test light does not illuminate, go to step 19 .
Replace any faulty fuel injector(s). After replacing injector(s), go to step 31 .
Check affected fuel injector driver circuit(s) for an open, short to ground or short to voltage. If problem is found, go to next step. If circuit is okay, go to step 28 .
Repair as necessary. After repairs, go to step 31 .
Repair open ignition feed circuit between fuel injector harness connector and fuel injector. After repairs, go to step 31 .
Check resistance of spark plug cable on affected cylinder. If resistance is less than 30,000 ohms, go to next step. If resistance is not less than 30,000 ohms, go to step 28 .
Turn ignition off. Disconnect PCM harness connector. Reconnect Spark Tester (J-26792) on affected spark plug wire. Turn ignition on. Connect a fused jumper wire to battery voltage. Momentarily touch jumper to affected IC circuit at PCM harness connector. DO NOT leave jumper wire connected for longer than 5 seconds. If spark is present at spark tester when jumper is removed from IC circuit, go to step 26 . If spark is not present at spark tester when jumper is removed from IC circuit, go to next step.
Turn ignition off. Disconnect ICM harness connector. Check affected IC circuit for an open or short. Repair as necessary. After repairs, go to step 30 . If circuit is okay, go to next step.
Remove ignition coil from cylinder that did no have a spark. Check secondary coil resistance. If coil resistance is 5000-8000 ohms, go to next step. If coil resistance is not 5000-8000 ohms, go to step 29 .
Install a known-good ignition coil. Reconnect ICM harness connector. Connect spark tester to affected cylinder. Turn ignition on. Momentarily touch jumper wire to affected IC circuit at PCM connector. If spark is present at spark tester, go to step 30 . If spark is not present at spark tester, go to next step.
Check for poor connection at ICM. Repair a necessary. If connection is okay, replace ICM. After replacing ICM, go to step 30 .
Check for poor PCM connection. Repair as necessary. After repairs, go to step 30 . If connection is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 30 .
Replace spark plug cables. After replacing spark plug cables, go to step 30 .
Replace faulty ignition coil. After replacing ignition coil, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0300. If scan tool indicates that test RAN AND PASSED, go to next step. If scan tool does not indicate that test RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose affected DTCs. If no other DTCs are set, system is okay.

A intermittent can be caused by a defective CKP sensor reluctor wheel. Remove CKP sensor. Inspect reluctor wheel through CKP sensor mounting hole. Check porosity and condition of reluctor wheel. If reluctor wheel is okay, see appropriate TROUBLE SHOOTING - NO CODES article for intermittent diagnosis.

DTC P0300: ENGINE MISFIRE DETECTED (2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 or P1621 not set.
Misfire total is 12 counts or more.
Engine speed is 469-6400 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7 to 123°C).
Engine running longer than 5 seconds.
TP sensor angle has not changed more than 8 percent in one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P0200 is also set, diagnose DTC as necessary before proceeding. If DTC P0200 is not set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 26 . If no problems were found, go to next step.
Start engine and allow it to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If any MISFIRE CURRENT counters are incrementing, go to step 6 . If MISFIRE CURRENT counters are not incrementing, go to next step.
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If any of MISFIRE CURRENT counters are incrementing, go to next step. If MISFIRE CURRENT counters are not incrementing, go to step 26 .
If all counters are equal (within one percent of each other), go to next step. If all counters are not equal, go to step 11 .
Turn ignition off. Install fuel pressure gauge. Start engine and allow it to idle. If fuel pressure is 31-44 psi (2.2-3.1 kg/cm 2 ), go to next step. If fuel pressure is not 31-44 psi (2.2-3.1 kg/cm 2 ), see BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Check for fuel contamination. If fuel is contaminated, go to step 10 . If fuel is not contaminated, go to next step.
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted airflow etc.). Repair as necessary. After repairs, go to step 26 .
Replace contaminated fuel. After repairs, go to step 26 .
Turn ignition off. Disconnect fuel injector harness connector. Temporarily remove ignition coil and Ignition Control Module (ICM) assembly. Install Spark Plug Jumper Wires (J-36012). Install Spark Tester (J-26792) to spark plug jumper for each cylinder, one at a time. Disconnect spark plug boot from companion cylinder at ignition coil housing and install a jumper wire between ground and spark plug connector at ignition coil housing (1-4 or 2-3). Crank engine and check for spark. If spark is present at all cylinders, go to next step. If spark is not present at one or more cylinders, go to step 13 .
Check for faulty spark plugs. Replace defective spark plug(s) as necessary. After repairs, go to step 26 . If spark plugs are okay, go to step 9 .
Turn ignition off. Remove boot assemblies from affected ignition coil. Using a DVOM, measure secondary resistance of coil. If resistance is less than 10,000 ohms, go to next step. If resistance is not less than 10,000 ohms, go to step 15 .
Remove ignition coil housing. Disconnect coil harness connector at ICM. Connect a test light between positive battery terminal and coil driver circuit terminal at ICM that did not have spark. Crank engine and observe test light. If test light flashes, go to step 16 . If test light does not flash, go to step 17 .
Remove ignition coil from ignition coil housing. Recheck secondary resistance of coil. If resistance is less than 10,000 ohms, go to step 18 . If resistance is not less than 10,000 ohms, go to step 19 .
Repair open or shorted ignition coil wiring harness, poor ignition coil connector or replace ignition coil, ignition coil housing or boot assembly. After repairs, go to step 26 .
Disconnect and inspect ICM 11-pin connector. Repair as necessary. After repairs, go to step 26 . If connector is okay, go to step 20 .
Replace ignition coil springs for affected cylinder. After repairs, go to step 26 .
Replace suspect coil. After repairs, go to step 26 .
Turn ignition off. Disconnect ICM 11-pin connector. Check resistance between ground and each ignition control circuit terminal at ICM harness connector. If both resistances are 600-2600 ohms, go to next step. If either resistance is not 600-2600 ohms, go to step 22 .
Replace ICM module. After replacing module, go to step 26 .
Disconnect and inspect PCM connector terminals. If connector is not okay, go to step 24 . If connector is okay, go to next step.
Check for an open or short in ignition control circuit(s). Repair as necessary. After repairs, go to step 26 . If circuits are okay, go to step 25 .
Repair connector terminals. After repairs, go to step 26 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0300. If scan tool indicates that test RAN AND PASSED, go to next step. If scan tool does not indicate that test RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0300: ENGINE MISFIRE DETECTED (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor sends pulses to ECM as reluctor wheel teeth rotate past sensor. Besides using these pulses to synchronize ignition and fuel injector operation, ECM also times interval between each pulse and compares each new time interval with previous one to determine when an excessive change in crankshaft speed has occurred.

A misfire causes an unexpected change in crankshaft speed. A certain amount of acceleration/deceleration is expected between each firing stroke, but if crankshaft speed changes more than expected amount, ECM will interpret this as a misfire. ECM continuously calculates crankshaft position from CKP sensor signals.

This information is used to determine which cylinder is misfiring so ECM can increment appropriate misfire counter and set appropriate DTC, if necessary. If ECM is able to determine a specific cylinder is misfiring, DTC for that cylinder will set. If misfire is random and on multiple cylinders, DTC P0300 will set. Conditions for setting DTC

Misfire greater than legislated limit (amount of misfire ranging from 1.0-12.5 percent).
Condition must be met for at least 5 camshaft revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTCs P0201-P0206 are also set, go to applicable DTC. If DTCs P0201-P0206 are not present, go to next step.
If DTC P1460 is set, go to step 5 . If DTC P1460 is not set, go to next step.
If DTCs P0301-P0306 are also set, go to applicable DTC. If DTCs P0301-P0306 are not present, go to step 8 .
Using scan tool, monitor fuel level voltage. If scan tool reading is greater than 6.8 volts, go to next step. If scan tool reading is not greater than 6.8 volts, go to step 8 .
Add 5 gallons of fuel to fuel tank. If fuel level voltage is less than 6.8 volts, go to step 13 . If fuel level voltage is not less than 6.8 volts, go to next step.
Repair fuel sending unit or circuit problem. After repairs, go to next step.
Start and idle engine. Using scan tool, monitor all misfire current counters (6 counters, one per cylinder). If any misfire current counters increase, go to next step. If any misfire current counters do not increase, go to step 10 .
Inspect vacuum hoses for splits, kinks and proper connections. Check throttle body and intake manifold for vacuum leaks. Check PCV valve operation and system for vacuum leaks. Ensure ECM grounds are clean and secure. Ensure all injector harness connectors and spark plug wires are installed at correct locations and secure. Repair as necessary. After repairs, go to step 13 . If all components and systems are okay, go to next step.
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0300 is set, go to next step. If DTC P0300 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Remove spark plug(s) as necessary and inspect for signs of oil or coolant fouling. Replace spark plug(s) or repair engine as necessary. If spark plugs are okay, go to next step.
Check spark plugs for cracks or damage, excessive wear or improper gap. Check for carbon tracking on insulator. Replace components as necessary. After repairs, go to next step. If components are okay, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0300 is set, go to step 2 . If DTC P0300 is not set, go to next step.
If other DTCs were present during OBD system check and has not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

If DTC P1430 was also set, and no misfire is currently present, vehicle may simply have been run low on fuel. This DTC being present with properly functioning fuel sending circuit eliminates need for a lengthy misfire diagnosis.

A misfire DTC could be caused by excessive vibration from sources other than engine. Possible sources could be an out of balance or out of round tire, out of round brake rotor or drum, drive shaft out of balance or rough road.

DTC P0300: ENGINE MISFIRE DETECTED (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When PCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. PCM determines misfires on each cylinder and evaluates a random misfire and set DTC. Conditions for setting DTC

No VSS DTCs set.
No CKP, CMP, ECT, MAF, MAP or TP sensor DTCs set.
Engine speed 450-5800 RPM.
System voltage 9-16 volts.
ECT 21-248°F (-6-120°C).
Throttle angle steady.
PCM detects crankshaft RPM variation, indicating a misfire which could cause catalytic convertor damage or high emissions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P1200 is also set, go to DTC P1200. If DTC P1200 is not set, go to next step.
Start engine and allow it to idle. Using scan tool, read and record FREEZE FRAME data. Operate vehicle within conditions noted in FREEZE FRAME data. Using scan tool, read MISFIRE CUR # display for each cylinder. If MISFIRE CUR # is increasing (indicating a misfire currently occurring) for any cylinder, go to next step. If MISFIRE CUR # is not increasing, go to «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If MISFIRE HIST # displays a very large number for more than one cylinder, go to next step. If MISFIRE HIST # does not display a very large number for more than one cylinder, go to step 14 .
Check vacuum hoses for splits, kinks, or improper connections. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Check PCV valve for improper installation or damaged "O" rings. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Check throttle body inlet screen for blockage or foreign objects which may partially block airflow sample through MAF sensor. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Check fuel pressure. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Check for fuel contamination. If fuel is contaminated, repair condition causing contamination. After repairs, go to step 30 . If fuel is okay, go to next step.
Check PCM power and sensor grounds for clean and tight connection, and for proper location. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Disconnect MAF sensor harness connector. Operate vehicle within conditions noted in FREEZE FRAME data. Using scan tool, read MISFIRE CUR # display for each cylinder. If MISFIRE CUR # is increasing (indicating a misfire currently occurring) for any cylinder, go to next step. If MISFIRE CUR # is not increasing, go to step 27 .
Check intake manifold, injector "O" rings, EGR adapter, EGR valve, and EGR feed pipes for vacuum leaks. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Remove EGR valve and inspect valve, seat and passages for damage. Inspect valve pintle to ensure it is not sticking partially open. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Check for proper injector operation. Install Adaptor Harness (J-34730-380 & J-34730-385) to 10-pin fuel injector harness connector. Attempt to start engine. If all LEDs for cylinders No. 1-6 flashes, go to next step. If not all LEDs for cylinders No. 1-6 flashes, go to step 16 .
Check for proper injector operation. See INJECTOR CIRCUIT TEST under FUEL SYSTEM DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to step 17 .
Check affected injector circuit(s) from PCM for open, shorted to ground, or for poor connection. Repair as necessary. After repairs, go to step 30 . If circuits are okay, go to step 29 .
Check ignition wire(s) associated with cylinder(s) that is misfiring. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Install a spark tester on spark plug wire at spark plug end for cylinder indicating most severe misfire. Connect a jumper wire between engine ground and companion cylinder spark plug wire at spark plug end. Companion cylinders are 1/4, 2/5, and 3/6. Crank engine and check for crisp, Blue spark at tester. Repeat procedure for each affected cylinder. If spark is okay on all cylinders, go to step 23 . If spark is not okay on any cylinder, go to next step.
Remove ignition coil(s) associated with misfiring cylinder(s). Check ignition coils for cracks or carbon tracking. If a problem is found, replace damaged coil(s). After repairs, go to step 30 . If no problem is found, go to next step.
Check ignition coil secondary resistance. If resistance is not 5000-8000 ohms, replace ignition coil. After replacing ignition coil, go to step 30 . If resistance is as specified, go to next step.
Remove ignition wire(s) associated with misfiring cylinder(s). Check ignition wire(s) boot for carbon tracking or damaged insulation. If a problem is found, replace faulty ignition wire(s). After repairs, go to step 30 . If no problem is found, go to next step.
Check resistance of ignition wire(s) associated with misfiring cylinder(s). If resistance is greater than 30,000 ohms, replace ignition wire(s). After replacing wire(s), go to step 30 . If resistance is not greater than 30,000 ohms, go to step 28 .
Remove spark plug(s) associated with misfiring cylinder(s). Check spark plugs for excessive fouling. If spark plugs are excessively fouled, diagnose and repair mechanical engine problem. If spark plugs are not excessively fouled, go to next step.
Check spark plug insulation for cracks, carbon tracking or other damage. If a problem is found, replace faulty spark plug(s). After replacing spark plug(s), go to step 30 . If no problem is found, go to next step.
Diagnose mechanical engine problem. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, go to next step.
Check for transmission DTCs. See appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS. If a problem is found, repair as necessary. After repairs, go to step 30 . If no problem is found, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Replace MAF sensor. After replacing sensor, go to step 30 .
Replace ignition control module. After replacing module, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, read and record FREEZE FRAME data. Clear DTCs. Start engine and allow it to idle. Operate vehicle within conditions noted in FREEZE FRAME data. Using scan tool, read MISFIRE CUR # display for each cylinder. If MISFIRE CUR # is increasing (indicating a misfire currently occurring) for any cylinder, repeat step 2 . If MISFIRE CUR # is not increasing, repair is complete.

Check secondary ignition wires. Check for damaged or faulty ignition coil. Substitute a known-good ignition coil. Check system grounds. Check MAF sensor, air induction system, fuel pressure, injectors, and EGR valve.

Extended idle periods or short trip driving could leave deposits on HO2S. Deposits could cause HO2S to respond slowly, affecting fuel control and causing misfire at idle.

DTC P0300: ENGINE MISFIRE DETECTED (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

No transaxle or VSS DTCs set.
No CKP, CMP, ECT, MAF or TP sensor DTCs set.
Engine speed 450-5800 RPM.
ECT 19-248°F (-7-120°C).
Throttle steady.
PCM detects crankshaft RPM variation, indicating a misfire which could cause catalytic convertor damage or high emissions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P1200 is also set, go to DTC P1200. If DTC P1200 is not set, go to next step.
Start engine and allow it to idle. Using scan tool, read and record FREEZE FRAME data. Operate vehicle within conditions noted in FREEZE FRAME data. Using scan tool, read MISFIRE CUR # display for each cylinder. If MISFIRE CUR # is increasing (indicating a misfire currently occurring) for any cylinder, go to next step. If MISFIRE CUR # is not increasing, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If MISFIRE HIST # displays a very large number for more than one cylinder, go to next step. If MISFIRE HIST # does not display a very large number for more than one cylinder, go to step 14 .
Check vacuum hoses for splits, kinks, or improper connections. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Check PCV valve for improper installation or damaged "O" rings. If a problem is found, go to step 27 . If no problem is found, go to next step.
Check throttle body inlet screen for blockage or foreign objects which may partially block airflow sample through MAF sensor. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Perform injector balance test. See appropriate SYSTEM & COMPONENT TESTING article. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Check for fuel contamination. If fuel is contaminated, repair condition causing contamination. After repairs, go to step 27 . If fuel is okay, go to next step.
Check PCM injector, power and sensor grounds for clean and tight connection, and for proper location. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Disconnect MAF sensor harness connector. Operate vehicle within conditions noted in FREEZE FRAME data. Using scan tool, read MISFIRE CUR # display for each cylinder. If MISFIRE CUR # is increasing (indicating a misfire currently occurring) for any cylinder, go to next step. If MISFIRE CUR # is not increasing, go to step 25 .
Check intake manifold, injector "O" rings, EGR adapter, EGR valve, and EGR feed pipes for vacuum leaks. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Remove EGR valve and inspect valve, seat and passages for damage. Inspect valve pintle to ensure it is not sticking partially open. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Perform injector circuit test. See appropriate BASIC DIAGNOSTIC PROCEDURES article. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Check ignition wire(s) associated with cylinder(s) that is misfiring. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Install a spark tester on spark plug wire at spark plug end for cylinder indicating most severe misfire. Connect a jumper wire between engine ground and companion cylinder spark plug wire at spark plug end. Companion cylinders are 1 and 4, 2 and 5, and 3 and 6. Crank engine and check for crisp, blue spark at tester. Repeat procedure for each affected cylinder. If spark is okay on all cylinders, go to step 21 . If spark is not okay on any cylinder, go to next step.
Remove ignition coil(s) associated with misfiring cylinder(s). Check ignition coils for cracks or carbon tracking. If a problem is found, replace damaged coil(s) and go to step 27 . If no problem is found, go to next step.
Check ignition coil secondary resistance. If resistance is not 7000 ohms on VIN 1 or 10,000 ohms on VIN K, replace ignition coil. After replacing coil, go to step 27 . If resistance is as specified, go to next step.
Remove ignition wire(s) associated with misfiring cylinder(s). Check ignition wire(s) boot for carbon tracking or damaged insulation. If a problem is found, replace faulty ignition wire(s). After replacing ignition wire(s), go to step 27 . If no problem is found, go to next step.
Check resistance of ignition wire(s) associated with misfiring cylinder(s). If resistance is not 5000-8000 ohms, replace ignition wire(s). After replacing ignition wire(s), go to step 27 . If resistance is 5000-8000 ohms, go to step 26 .
Remove spark plug(s) associated with misfiring cylinder(s). Check spark plugs for excessive fouling. If spark plugs are excessively fouled, diagnose and repair mechanical engine problem. If spark plugs are not excessively fouled, go to next step.
Check spark plug insulation for cracks, carbon tracking or other damage. If a problem is found, replace faulty spark plug(s). After replacing spark plug(s), go to step 27 . If no problem is found, go to next step.
Diagnose mechanical engine problem. Repair as necessary. After repairs, go to step 27 . If no problem is found, go to next step.
Check for transmission DTCs. See appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS. Repair as necessary. After repairs, go to step 27 . If no problem is found, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Replace MAF sensor. After replacing sensor, go to step 27 .
Replace ignition control module. After replacing module, go to next step.
Using scan tool, read and record FREEZE FRAME data. Clear DTCs. Start engine and allow it to idle. Operate vehicle within conditions noted in FREEZE FRAME data. Using scan tool, read MISFIRE CUR # display for each cylinder. If MISFIRE CUR # is increasing (indicating a misfire currently occurring) for any cylinder, return to step 2 . If MISFIRE CUR # is not increasing, repair is complete.

Extended idle periods or short trip driving could leave deposits on HO2S. Deposits could cause HO2S to respond slowly, affecting fuel control and causing misfire at idle.

DTC P0300: ENGINE MISFIRE DETECTED (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

This test is used to detect misfires in any cylinder. A misfire occurs when there is a complete lack of combustion in the cylinder. A misfire will cause a fluctuation in crankshaft revolution speed. PCM uses the time between 4X reference pulses to determine when these fluctuations occur. At lower speeds, fluctuations in crankshaft speed are measured each reference pulse to detect misfire. At higher engine speeds, fluctuations in crankshaft speed are monitored over 2 engine revolutions and fluctuations in crankshaft speed at each half revolution are compared to compute a balance number. The 4X reference pulses originate in the ignition control module and vary with RPM.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on. Using scan tool, check for any other DTCs present. If other DTCs are present, diagnose affected DTCs first. If other DTCs are not present, go to next step.
Start and idle engine. Using scan tool, observe MISFIRE CUR. counters in the misfire data list (there are 8 counters, one for each cylinder). If any of the counters are incrementing, go to next step. If counters are not incrementing, go to step 15 .
Turn ignition off. Connect Spark Tester (ST-125) to ignition wire(s) that indicated a misfire. Ground the companion cylinder(s) plug wire. Start engine. If spark is present and consistent at spark tester, go to next step. If spark is not present or is intermittent at spark tester, go to step 9 .
Turn ignition off. Remove and check spark plug from affected cylinder(s). If spark plug is okay (not oil or coolant fouled), diagnose fuel injector. See appropriate SYSTEM & COMPONENT TESTING article. If spark plug is fouled, go to next step.
If spark plug is oil or coolant fouled, check engine for mechanical problems. If spark plug is not fouled, go to next step.
If spark plug is cracked or improperly gapped, go to next step. If spark plug is okay, diagnose fuel injector(s). See appropriate SYSTEM & COMPONENT TESTING article.
Replace or re-gap spark plug.
Turn ignition off. Using DVOM, check resistance of each affected spark plug wire. If resistance is less than 15,000 ohms, go to next step. If resistance is not less than 15,000 ohms, go to step 13 .
Remove affected coil(s). Check for carbon tracking on coil. If carbon tracking is not present, go to next step. If carbon tracking is present, go to step 12 .
Switch position of coils at affected cylinder. Start and idle engine. If spark is present and consistent on spark tester, go to next step. If spark is not present or not consistent, go to step 14 .
Turn ignition off. Replace faulty ignition coil and spark plug wire.
Replace spark plug wire.
Replace ignition control module.
Turn ignition on, with engine off. Review DTC P0300 snapshot data. Note conditions that the vehicle was operating when DTC was set and operate vehicle under the same condition. Using scan tool, observe MISFIRE CUR. counters in the misfire data list. If any of the counters are incrementing, repeat step 4 . If counters are not incrementing, go to next step.
Turn ignition on, with engine off. Using scan tool, observe MISFIRE HIST. counters in the misfire data list. If more than 3 cylinders show a high misfire rate, go to step 18 . If less than 3 cylinders show a high misfire rate, go to next step.
Note cylinder that shows a higher number of misfire. Check affected cylinder for damaged or high resistance spark plug wire, vacuum leak, damaged spark plug, etc. Repair as necessary. If no problems are found, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Check engine for proper vent operation, vacuum leaks or intermittent rich or lean condition. Repair as necessary. If not problems are found, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .

If more than one cylinder showed a history code of misfire, look for something in common between the cylinders such as, shared coils, etc. Also, check for vacuum leaks at the affected cylinder.

If fault cannot be duplicated, mist secondary ignition system with water and operate vehicle under conditions that set the DTC.

DTC P0300: MISFIRE DETECTED (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor and camshaft position sensor are used to detect misfire. VCM monitors crankshaft speed and detects deceleration or acceleration of crankshaft that are not associated with normal engine speed. CKP sensor information is compared to engine speed and engine load to determine if a misfire occurred.

If a misfire is present, crankshaft position is compared to camshaft position sensor signal to determine which cylinder misfired. Information will be stored in separate accumulators for each cylinder. VCM evaluates number of misfires in each accumulator. A random misfire is determined if accumulators are somewhat the same, or if 3 or more cylinders are misfiring.

VCM also utilizes input from front wheel speed sensor to determine if a rough road condition exists which could cause crankshaft acceleration and deceleration. Diagnostic will not run if a rough road condition exists. Conditions for setting DTC

No MAF, TP or VS sensor DTCs set.
No IC control DTCs are set.
No CKP or CMP sensor DTCs set.
Fuel level greater than 10 percent.
ECT 19°F (-7°C).
Engine speed is 450-5000 RPM.
System voltage 11-16 volts.
Positive or negative throttle position change is less than 1.9 percent for 100 milliseconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Using scan tool, review FAILURE RECORDS DATA. Check if any other DTCs are set. If other DTCs are set, go to applicable DTC test. If no other DTCs are set, go to next step.
Using scan tool, perform CKP SYSTEM VARIATION LEARNING PROCEDURE. After performing CKP learn procedure, go to next step.
Start and operate engine at idle. Using scan tool, monitor MAP sensor voltage. If MAP sensor voltage is greater than 4 volts, go to DTC P0108 diagnostic test. If MAP sensor voltage is not greater than 4 volts, go to next step.
Using FREEZE FRAME and FAILURE RECORDS data on scan tool, duplicate conditions required for misfire. If scan tool indicates that this DTC failed this ignition cycle, go to next step. If scan tool does not indicate that this DTC failed this ignition cycle, go to step 11 .
Using scan tool, review misfire index. If misfire index is increasing for more than one cylinder, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If not, go to next step.
Install Spark Tester (J-26792) on spark plug wire No. 1. Disconnect fuel injector harness at intake manifold. Crank engine. Spark should jump tester gap. Repeat for each spark plug wire. If spark is adequate on all spark plug wires, go to next step. If spark is not adequate on all spark plug wires, check ignition system. See appropriate BASIC DIAGNOSTIC PROCEDURES article.
Inspect spark plugs for wear, excessive air gap, cracks or fouling. If spark plug are okay, go to next step. If spark plugs are not okay, go to step 12 .
Perform a cylinder compression test. If a problem is found, go to step 14 . If no problem is found, go to next step.
Diagnose fuel injector circuit. See appropriate BASIC DIAGNOSTIC PROCEDURES article. If a problem is found, go to next step. If no problem is found, go to step 13 .
Misfire is intermittent and not currently occurring. Check if additional DTCs are set. Diagnose affected DTCs. If no additional DTCs are set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Replace spark plugs. After replacing spark plugs, go to step 14 .
Repair circuit as necessary. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Misfire index can be monitored using scan tool. Each cylinder has a misfire counter for current and history. Current misfire counter can be used to determine which cylinder is misfiring. Current misfire counter for a currently misfiring cylinder will be increased by a factor of 2. If VCM is unable to determine which cylinder is misfiring, counter will increase by a factor of one for each cylinder that may have misfired.

An intermittent misfire may be caused by spark plug wires, coil wires, contaminated fuel or low fuel level. Ensure spark plug wires are securely connected to spark plugs and distributor cap. Check wire routing for cross-firing. If misfire occurs during damp weather, check for worn plug wires. Spray wires with water with engine running and check for spark to jump from wires. If spark is present, replace wires.

Check fuel condition and quality. Dirty or contaminated fuel could cause misfire condition. If fuel level is low, contaminates on bottom of tank could be introduced into fuel system. Severely out of balance tires could result in DTC setting. Road test vehicle and check for out of balance tires or drive line components.

DTC P0300: ENGINE MISFIRE DETECTED (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Misfire is detected using Camshaft Position (CMP) and Crankshaft Position (CKP) sensors. When VCM senses CKP deceleration not associated with normal engine speed reduction, CMP is used to determine misfiring cylinder. VCM determines misfires on each cylinder, evaluates a random misfire, and sets DTC. Conditions for setting DTC

No CKP, IAC, MAF, TP or VSS sensor DTCs set.
Rough road not detected.
Engine speed 300-5600 RPM.
ECT at normal operating temperature.
System voltage 9-16 volts.
Positive or negative throttle position change is less than 2.9 percent for 100 msec.
A misfire is detected.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Review FAILURE RECORDS data. If other DTCs are stored, diagnose affected DTCs. If no other DTCs are present, go to next step.
Perform CKP System Variation Learn Procedure. See appropriate BASIC DIAGNOSTIC PROCEDURES article. After performing CKP learn procedure, go to next step.
Start and allow engine to idle. Using scan tool, monitor MAP sensor voltage. If voltage reading is greater than 4 volts, go to DTC P0108 for diagnosis. If voltage reading is not greater than 4 volts, go to next step.
Turn ignition off, then turn ignition on, with engine off. Duplicate conditions required to set DTC. Using scan tool, read DTC PRESENT THIS IGNITION CYCLE. If the scan tool displays DTC P0300, PRESENT THIS IGN, go to next step. If the scan tool does not display DTC P0300, PRESENT THIS IGN, go to step 11 .
Using scan tool, review misfire index. If misfire index is increasing for more than one cylinder, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If misfire index is not increasing for more than one cylinder, go to next step.
Install a spark tester on No. 1 spark plug wire. Disconnect fuel injector harness at intake manifold. Crank engine and check for spark at tester. Repeat procedure for each spark plug wire. If spark is adequate on all wires, go to next step. If spark is not adequate, diagnose ignition system. See appropriate BASIC DIAGNOSTIC PROCEDURES article.
Remove and check spark plugs for wear, excessive gap, cracks or fouling. If spark plugs are okay, go to next step. If spark plugs are not okay, go to step 12 .
Perform cylinder compression test. If engine mechanical problem is found, repair as necessary. After repairs, go to step 14 . If no mechanical problem is found, go to next step.
Perform injector circuit test. See appropriate BASIC DIAGNOSTIC PROCEDURES article. If fuel system is okay, go to next step. If fuel system is not okay, go to step 13 .
DTC is intermittent. Check if additional DTCs are present. Diagnose affected DTCs. If no additional DTCs are present, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Replace spark plugs. After replacing spark plugs, go to step 14 .
Repair as necessary. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter this DTC. Operate vehicle within conditions required to set DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. Check if any undiagnosed DTCs are displayed. Diagnose affected DTCs. If no additional DTCs are displayed, system is okay.

A misfire could be caused by excessive vibration from sources other than engine. Check following items for possible cause of misfire: tire/wheel out of balance/round, uneven brake rotor or drum surface, or a rough road condition. Check plug wires for proper installation and operation. Check fuel level, condition and quality. If problem is intermittent, see appropriate TROUBLE SHOOTING - NO CODES article.

DTC P0300: ENGINE MISFIRE DETECTED (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

PCM uses the Crankshaft Position (CKP) sensor for misfire detection and to control spark and fuel. As crankshaft rotates, the reluctor wheel teeth interrupt a magnetic field produced by a magnet within the sensor, producing a signal in which the PCM reads. PCM uses this 24X signal in combination with Camshaft Position (CAM) sensor 1X signal in order to accurately determine crankshaft position. PCM also calculates a 4X signal from this information for internal calculations. The 4X signal also provides a tach signal for any device that requires one.

DTC will set when PCM determines that an emission type misfire is present, preventing catalytic converter damage.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If other DTCs are set, diagnose affected DTCs first before proceeding with this test. To proceed with test, turn ignition on. Using scan tool, perform CKP SYSTEM VARIATION LEARN PROCEDURE. After performing CKP system variation learn procedure, start and operate engine at idle. Using scan tool, monitor all MISFIRE CURRENT counters in misfire data list (one counter per cylinder). If any of the misfire counters are incrementing, go to step 4 . If misfire counters are not incrementing, go to next step.
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data for this DTC and observe parameters. Turn ignition off for 15 seconds. Start engine. Operate vehicle within conditions recorded in FREEZE FRAME/FAILURE RECORDS. Using scan tool, select DTC option, SPECIFIC DTC, then enter the DTC number. If scan tool indicates that this diagnostic failed this ignition cycle, go to next step. If scan tool does not indicate that this diagnostic failed this ignition cycle, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If only one misfire counter is incrementing, go to step 6 . If more than one misfire counters are incrementing, go to next step.
Check vacuum hoses for leaks or kinks. Check throttle body or intake manifold for vacuum leaks. Ensure PCM grounds are clean and tight. Inspect ignition coil and module ground circuit for open on the side of the engine that has more than one cylinder misfiring. Ensure injector harness connectors are connected to proper cylinder. Check for open injector and ignition control fuses. Check for proper fuel pressure or restricted exhaust. Repair as necessary. After repairs, go to step 17 . If no problems were found, go to next step.
Turn ignition off. Relieve fuel pressure. Disconnect injector that corresponds to the misfire current counter(s) that was incrementing. Connect Injector Test Light (J-34730-405) to injector harness connector. Start engine. If injector test light is flashing, go to next step. If injector test light is not flashing, go to DTC P0200 test.
Turn ignition off. Reconnect injector harness connector. Disconnect ignition wire from spark plug that corresponds to the misfire current counter(s) that was incrementing. Connect Spark Tester (J-26792) to spark plug. Start engine. If spark is present and consistent, go to step 9 . If spark is not present or is not consistent, go to next step.
Remove spark plug wire. Check spark plug wire resistance. If resistance is less than 700 ohms, diagnose ignition system. If resistance is not less than 700 ohms, go to step 16 .
Remove spark plug from affected cylinder. If spark plug is okay, go to next step. If spark plug is faulty, go to step 11 .
Swap suspected spark plug to another cylinder that is operating properly. Operate engine under the same conditions that misfire occurred. If misfire moved with the spark plug, go to step 15 . If misfire did not move with the spark plug, diagnose fuel injector.
If spark plug is oil or coolant fouled, diagnose engine for mechanical failure. If spark plug is not oil or coolant fouled, go to next step.
If spark plug is gas fouled, diagnose fuel system. If spark plug is not gas fouled, go to next step.
Check if spark plug is cracked, worn or improperly gapped. If spark plug is faulty, go to next step. If spark plug is not faulty, diagnose fuel injector.
Replace or re-gap spark plug. After replacing or re-gapping spark plug, go to step 17 .
Replace faulty spark plug. After replacing spark plug, go to step 17 .
Replace ignition wire(s). After replacing ignition wire(s), go to next step.
If MIL was flashing, go to DTC P0420 test.
Using scan tool, clear DTC. After clearing DTC, operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, go to step 2 .
Using scan tool, select CAPTURE INFO function. If any undiagnosed DTCs are displayed, go to affected DTC test.

If more than one cylinder showed a history code of misfire, look for something in common between the cylinders such as, shared coils, etc. Also, check for vacuum leaks at the affected cylinder.

If fault cannot be duplicated, mist secondary ignition system with water and operate vehicle under conditions that set the DTC.

DTC P0300: ENGINE MISFIRE DETECTED (5.7L "F" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor reluctor (4X) is located on side of engine block behind starter assembly. CKP sensor will send a pulse on every falling edge of 4X reluctor wheel. A misfire will cause a change in crankshaft speed. PCM times interval between each pulse and compares each new interval with previous one to determine when an excessive change in crankshaft speed has occurred. A certain amount of acceleration/deceleration is expected between each firing stroke, but if crankshaft speed changes are more than expected amount, PCM will interpret this as a misfire. PCM continuously calculates crankshaft position from low and high resolution signals. This information is used to determine which cylinder is misfiring so that PCM can increment appropriate misfire counter. Conditions for setting DTC

DTCs P0101, P0102, P0103, P0107, P0108, P0117, P0118, P0121, P0122, P0123, P0125, P0335, P0336, P0341, P0342, P0343, P0500, P0502, P0503 or P1258 not set.
Engine speed 450-3001 RPM.
Ignition voltage 11-16 volts.
Engine coolant temperature 19-266°F (-7-130°C).
Fuel level greater than 10 percent.
Throttle angle within one percent.
ABS and traction control not active.
Transmission not changing gears.
AIR diagnostics not active.
A/C clutch steady.
PCM not in fuel shut-off or decel fuel cut-off mode.
ABS signals not exceeding rough road thresholds.
PCM determines that an emission-type misfire is present.
PCM determines that a catalyst damaging misfire is present.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step. NOTE: If other DTCs, except P0131, P0132, P0133, P0151, P0152, P0153, P0171, P0172, P0174, P0175, P0351-P0358, P1133, P1135, P1136, P1153, P1155 or P1156 are present, diagnose affected DTCs first.
Start and operate engine at idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If any of misfire counter is incrementing, go to step 4 . If misfire counter is not incrementing, go to next step.
Turn ignition on, engine off. Review FREEZE FRAME and/or FAILURE RECORDS data for this DTC and observe parameters. Turn ignition off for 15 seconds. Start engine. Operate vehicle within conditions required to set this DTC. Using scan tool select DTC option and SPECIFIC DTC option, then enter DTC P0300. If scan tool indicates that this DTC failed this ignition, go to next step. If scan tool does not indicate that this DTC failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If only one cylinder is misfiring, go to step 6 . If more than one of cylinders is misfiring, go to next step.
Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve or PCV system. Check PCM grounds for proper connection. Check that all injector harness connectors are connected to proper injector/cylinder. Repair as necessary. After repairs, go to step 17 . If components are okay, or repair is not necessary, go to next step.
Turn ignition off. Disconnect injector harness connector that corresponds to misfire counter that was incrementing. Connect an injector test light to injector harness connector. Start engine. If injector test light if flashing, go to next step. If injector test light is not flashing, diagnose injector circuit. See appropriate SYSTEM & COMPONENT TESTING article.
Turn ignition off. Reconnect injector harness connector. Disconnect ignition wire to spark plug that corresponds to misfire current counter that was incrementing. Install Spark Plug Tester (J-26792) to spark plug wire. Start engine. If spark is present at spark plug tester, go to step 9 . If spark is not present, go to next step.
Check resistance of affected spark plug wire. If resistance is less than 700 ohms, replace ignition wire. If resistance is not less than 700 ohms, go to step 16 .
Remove and check spark plug from affected cylinder. If spark plug is okay, go to next step. If spark plug is faulty, go to step 11 .
Swap spark plug to another cylinder that is operating properly. Operate vehicle under same conditions that misfire occurred. If misfire moved with spark plug, go to step 15 . If misfire is still present at original cylinder, perform fuel injector coil test. See appropriate SYSTEM & COMPONENT TESTING article.
If spark plug is fouled with oil or coolant, diagnose mechanical engine problem. If spark plug is not fouled, go to next step.
Check if spark plug is fouled with gasoline. If spark plug is gasoline fouled, diagnose fuel system. See appropriate SYSTEM & COMPONENT TESTING article. If spark plug is not gasoline fouled, go to next step.
Check spark plug for signs of cracks, wear or improper gap. If spark plug is faulty, go to next step. If spark plug is okay, check fuel injector resistance. See appropriate SYSTEM & COMPONENT TESTING article.
Replace or re-gap spark plug. After replacing or re-gapping spark plug, go to step 17 .
Replace faulty spark plug(s). After replacing spark plug(s), go to step 17 .
Replace faulty spark plug wire. After replacing spark plug wire, go to next step.
If complaint is due to MIL flashing, perform DTC P0420 or P0430 test. If MIL is not flashing, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0300. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

A misfire could be caused by excessive vibration from sources other than engine. Check following for possible cause, tire/wheel out of balance/round, uneven brake rotor or drum surface, or a rough road condition. If problem is intermittent, see appropriate TROUBLE SHOOTING - NO CODES article.

DTC P0300: ENGINE MISFIRE DETECTED (5.7L "Y" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor is mounted through side of engine block at rear of bank 2, behind starter. CKP reluctor (24X) is located on crankshaft, immediately in front of rear main bearing. CKP sensor will send a pulse on every falling edge of 24X reluctor wheel. A misfire will cause a change in crankshaft speed. PCM times interval between each pulse and compares each new interval with previous one to determine when an excessive change in crankshaft speed has occurred. A certain amount of acceleration/deceleration is expected between each firing stroke, but if crankshaft speed changes are more than expected amount, PCM will interpret this as a misfire. PCM continuously calculates crankshaft position from low and high resolution signals. This information is used to determine which cylinder is misfiring so that PCM can increment appropriate misfire counter. Conditions for setting DTC

DTCs P0101, P0102, P0103, P0107, P0108, P0117, P0118, P0125, P0335, P0336, P0341, P0342, P0343, P0500, P0502, P0503, P0601, P0742, P1120, P1220, P1221 or P1258 not set.
Engine speed 400-3000 RPM.
Ignition voltage 11-16 volts.
Engine coolant temperature 19-266°F (-7-130°C).
Fuel level more than 10 percent.
Throttle angle steady within one percent.
ABS and traction control not active.
Transmission not changing gears.
AIR diagnostics not active.
A/C clutch steady.
Not in fuel-shutoff or decel fuel cut-off.
ABS signals not exceeding rough road thresholds.
PCM determines that an emission-type misfire is present.
PCM determines that a catalyst damaging misfire is present.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step. NOTE: If other DTCs, except P0131, P0132, P0133, P0151, P0152, P0153, P0171, P0172, P0174, P0175, P0351, P0352, P0353, P0354, P0355, P0356, P0357, P0358, P1133, P1135, P1136, P1153, P1155 or P1156 are present, diagnose affected DTCs first.
Start and operate engine at idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If any misfire counter is incrementing, go to step 4 . If no misfire counter is incrementing, go to next step.
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function then enter DTC P0300. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If only one cylinder is misfiring, go to step 6 . If more than one of cylinders are misfiring, go to next step.
Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve or CCV system. Check PCM grounds for proper connection. Check that all injector harness connectors are connected to proper injector/cylinder. Check injector and control fuses for open. Check low fuel pressure or restricted fuel flow. Repair as necessary. After repairs, go to step 17 . If components are okay, or repair is not necessary, go to next step.
Turn ignition off. Disconnect injector connector to affected cylinder(s). Connect injector test light to injector connector. Start and operate engine at idle. If injector test light flashes, go to next step. If injector test light does not flash, perform fuel injector coil test. See appropriate SYSTEM & COMPONENT TESTING article.
Turn ignition off. Reconnect injector connector(s). Disconnect spark plug wire to affected cylinder(s). Connect spark tester between ground and spark plug wire. Crank engine. If spark is present, go to step 9 . If spark is not present, go to next step.
Using DVOM, check spark plug wire to affected cylinder(s). If resistance is less than 700 ohms, diagnose ignition system. See appropriate SYSTEM & COMPONENT TESTING article. If resistance is not less than 700 ohms, go to step 16 .
Remove and check spark plug from affected cylinder(s). If spark plug is okay, go to next step. If spark plug is not okay, go to step 11 .
Swap spark plug to another cylinder that is operating properly. Operate vehicle under same conditions that misfire occurred. If misfire moved with spark plug, go to step 15 . If misfire is still present at original cylinder, perform fuel injector coil test. See appropriate SYSTEM & COMPONENT TESTING article.
If spark plug is fouled with oil or coolant, diagnose mechanical engine problem. If spark plug is not fouled, go to next step.
If spark plugs are gas fouled, diagnose fuel system. See appropriate SYSTEM & COMPONENT TESTING article. If spark plug is not fouled, go to next step.
Check spark plug for signs of cracks, wear or improper gap. If spark plug is faulty, go to next step. If spark plug is okay, perform fuel injector coil test. See appropriate SYSTEM & COMPONENT TESTING article.
Replace or re-gap spark plug. After replacing or re-gapping spark plug, go to step 17 .
Replace faulty spark plug(s). After replacing spark plug(s), go to step 17 .
Replace faulty spark plug wire(s). After replacing spark plug wire(s), go to next step.
If complaint is due to MIL flashing, perform DTC P0420 or P0430 test. If MIL is not flashing, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Running vehicle out of fuel may set this DTC or DTCs P0461 and P1431. Check for restriction in fuel filter or fuel lines. If problem is intermittent, see appropriate TROUBLE SHOOTING - NO CODES article.

DTC P0301, P0302, P0303 OR P0304: SPECIFIC CYLINDER MISFIRE DETECTED (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC P0301 (Cyl. 1), P0302 (Cyl. 2), P0303 (Cyl. 3) or P0304 (Cyl. 4) will set if a misfire has been detected after a series of tests when engine speed when engine speed is 469-7188 RPM, traction control fuel cut-off is not active, coolant temperature is 20-244°F (-7 to 118°C), throttle change is not rapid, not in decel fuel cut-off mode, ignition voltage at 8-15 volts and no TP sensor, CKP, IAT, MAT or ECT DTCs have been set. Misfire diagnostics are continuously checked with engine running when these conditions have been met.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Check for grounded/arching ignition wires. Repair or replace as necessary. If wires are okay, go to next step.
Based on specific misfire DTC set, remove that affected cylinder's spark plug wire. Connect a spark tester to spark plug wire. Test for spark. If spark is consistent, go to next step. If spark is not consistent, check for faulty wire and/or coil pack. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Remove spark plug from affected cylinder. Check spark plug gap (.060 in). Replace defective spark plug. If spark plug is okay, go to next step.
Perform injector balance test. Use scan tool to pulse each injector and note fuel pressure drop. Re-prime fuel rail after each cylinder is tested. See appropriate BASIC DIAGNOSTIC PROCEDURES article. If pressure drop is consistent (1.5 psi), go to next step. If pressure is not consistent, go to step 7 .
Perform compression test on misfiring cylinder. Normal compression is 185-205 psi (13-14 kg/cm 2 ). If compression is okay, replace spark plug(s). If compression is not okay, check for internal mechanical engine problem. Repair as necessary.
Check injector resistance. Resistance should be 12 ohms. If resistance is as specified, check for stuck injector pintle valve or clogged injector. Clean or replace injector. If resistance is not as specified, replace injector and retest engine.

Injector Resistance - 12 Ohms
Wire Resistance - Less Than 12,000 Ohms
Coil Pack Resistance - 8000-15,000 Ohms (Tower To Tower)
Spark Plug Gap - 0.060 in.

DTC P0301: CYLINDER NO. 1 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) monitors Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to detect if engine is misfiring. PCM looks for a sudden drop in crankshaft speed. This test is executed in blocks of 100 camshaft revolution tests. It may take several tests to set a DTC. Under light misfire conditions, it may take more than one trip to set a DTC. Severe misfire will flash Malfunction Indicator Light (MIL), indicating that catalytic converter damage is possible. Conditions for setting this DTC are as follows

Misfire total is greater than 12 counts.
Engine speed is 469-6406 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7 to 123°C).
Engine run time is longer than 15 seconds.
TP sensor angle has not changed more than 8 percent in one second.
DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 and P1621 not set.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If any other DTCs are set, diagnose DTCs as necessary before proceeding. If no other DTCs are set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 6 . If no problems are found, go to next step.
Start engine and allow it to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 1 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 1 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Install Spark Tester (J-26792) to cylinder No. 1 spark plug wire. Remove No. 4 spark plug wire from ignition coil. Connect a jumper wire between ground and ignition coil tower (where No. 4 spark plug wire was). Crank engine and check for spark. If spark is present, go to step 8 . If spark is not present, go to step 9 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 1 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 1 counter is not incrementing, go to next step.
If a repair was made after visual inspection was performed in step 3 , go to step 30 . If no problems were found in visual inspection, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Remove spark plug from No. 1 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 1 counter is incrementing, go to step 13 . If MISFIRE CURRENT NO. 1 counter is not incrementing, go to step 22 .
Remove spark plug wire from No. 1 cylinder. Using DVOM, check plug wire resistance. If resistance is less than 3000 ohms, go to next step. If resistance is not less than 3000 ohms, go to step 23 .
Remove ignition coil from cylinder that did not have spark. Check secondary resistance of coil. If resistance is 5000-8000 ohms, go to next step. If resistance is not 5000-8000 ohms, go to step 24 .
Replace ignition coil with a known-good coil. Crank engine and check for spark. If spark is present, go to step 24 . If spark is not present, go to next step.
Disconnect and inspect Ignition Control Module (ICM) 6-pin connector. Repair as necessary. After repairs, go to step 30 . If connector is okay, go to step 25 .
Turn ignition off. Disconnect all fuel injector connectors. Install injector test light on injector harness connector for No. 1 cylinder. Crank engine and observe test light. If test light flashes, go to next step. If test light does not flash, go to step 15 .
Perform INJECTOR BALANCE TEST. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article. If No. 1 injector is okay, go to step 28 . If No. 1 injector is not okay, go to step 29 .
Remove injector test light. Connect a standard test light between ground and ignition feed terminal at No. 1 injector harness connector. Crank engine and observe test light. If test light is on, go to next step. If test light is off, go to step 27 .
Turn ignition off. Disconnect PCM harness connectors. With test light connected to ground, probe injector driver circuit terminal at No. 1 injector harness connector. If test light is off, go to next step. If test light is on, go to step 26 .
With test light connected to positive battery terminal, probe injector No. 1 driver circuit terminal at No. 1 injector harness connector. If test light is off, go to next step. If test light is on, go to step 19 .
Inspect PCM connectors for damaged pins, corrosion and loose wires. If connectors are okay, go to step 20 . If connectors are not okay, go to step 21 .
Repair short to ground in cylinder No. 1 fuel injector driver circuit. After repairs, go to step 30 .
Replace PCM. Reprogram replacement PCM. After replacing PCM, go to step 30 .
Repair connector or connections as necessary. After repairs, go to step 30 .
Replace spark plug. After replacing spark plug, go to step 30 .
Replace spark plug wire. After replacing spark plug wire, go to step 30 .
Replace ignition coil. After replacing ignition coil, go to step 30 .
Replace ICM module. After replacing module, go to step 30 .
Repair short to voltage in cylinder No. 1 fuel injector driver circuit. After repairs, go to step 30 .
Repair open in ignition feed circuit. After repairs, go to step 30 .
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted air flow. etc.). Repair as necessary. After repairs, go to step 30 .
Replace defective fuel injector. After replacing fuel injector, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0301. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

An intermittent can be caused by a defective CKP sensor reluctor wheel. Remove CKP sensor. Inspect reluctor wheel through CKP sensor mounting hole. Check porosity and condition of reluctor wheel. If reluctor wheel is okay, see appropriate TROUBLE SHOOTING - NO CODES article for intermittent diagnosis.

DTC P0301: CYLINDER NO. 1 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0401, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 or P1621 not set.
Misfire total is greater than 12 counts.
Engine speed is 469-6400 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7 to 123°C).
Engine run time greater than 5 seconds.
TP sensor angle has not changed more than 8 percent in one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P0200 is also set, diagnose DTC as necessary before proceeding. If DTC P0200 is not set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 22 . If no problems are found, go to next step.
Start engine and allow it to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 1 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 1 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Temporarily remove ignition coil and Ignition Control Module (ICM) assembly. Install Spark Plug Jumper Wires (J-36012). Install Spark Tester (J-26792) on spark plug jumper for cylinder No. 1. Remove spark plug boot from cylinder No. 4 at ignition coil housing. Connect a jumper wire between ground and spark plug connector at ignition coil housing (where No. 4 spark plug boot was). With remaining spark plug boots still connected, crank engine and check for spark. If spark is present, go to step 7 . If spark is not present, go to step 10 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 1 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 1 counter is not incrementing, go to step 22 .
Remove spark plug from No. 1 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 1 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 1 counter is not incrementing, go to step 9 .
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted airflow, etc.). Repair as necessary. After repairs, go to step 22 .
Replace defective spark plug. After replacing spark plug, go to step 22 .
Turn ignition off. Remove boot assemblies from affected ignition coil. Using a DVOM, measure secondary resistance of coil. If resistance is less than 10,000 ohms, go to next step. If resistance is not less than 10,000 ohms, go to step 12 .
Remove ignition coil housing. Disconnect coil harness connector at ICM. Connect a test light between positive battery terminal and No. 1 and 4 ignition coil driver circuit terminal at ICM. Crank engine and observe test light. If test light flashes, go to step 13 . If test light does not flash, go to step 14 .
Remove ignition coil from ignition coil housing. Recheck secondary resistance of coil. If resistance is less than 10,000 ohms, go to step 15 . If resistance is not less than 10,000 ohms, go to step 16 .
Repair open or shorted ignition coil wiring harness, poor ignition coil connector or replace ignition coil, ignition coil housing or boot assembly. After repairs, go to step 22 .
Disconnect and inspect ICM 11-pin connector. Repair as necessary. After repairs, go to step 22 . If connector is okay, go to step 17 .
Replace ignition coil springs for cylinders No. 1 and 4 coil. After repairs, go to step 22 .
Replace ignition coil for cylinders No. 1 and 4. After repairs, go to step 22 .
Turn ignition off. Disconnect ICM 11-pin connector. Check resistance between ground and each ignition control circuit terminal at ICM harness connector. If all resistances are 600-2600 ohms, go to step 19 . If any of the resistance measurements is not 600-2600 ohms, go to next step.
Check for an open or short in ignition control circuit(s). Repair as necessary. After repairs, go to step 22 . If circuits are okay, go to step 20 .
Replace ICM module. After replacing module, go to step 22 .
Disconnect and inspect PCM connector terminals. Repair as necessary. After repairs, go to step 22 . If connector is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC which was set. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0301: CYLINDER NO. 1 MISFIRE DETECTED (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current counter for this cylinder. If misfire current counter increases, go to next step. If any misfire current counter does not increase, go to step 4 .
Inspect vacuum hoses for splits, kinks and proper connections. Check throttle body and intake manifold for vacuum leaks. Check PCV valve operation and system for vacuum leaks. Ensure ECM grounds are clean and secure. Ensure all injector harness connectors and spark plug wires are installed at correct locations and secure. Repair as necessary. After repairs, go to step 8 . If all components and systems are okay, go to step 5 .
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0301 is set, go to next step. If DTC P0301 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using Spark Plug Tester (J-26792), check spark at affected cylinder while cranking engine. If spark is present, go to next step. If spark is not present, diagnose ignition system. See BASIC IGNITION SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Remove spark plug(s) as necessary and inspect for signs of oil or coolant fouling. Replace spark plug(s) or repair engine as necessary. If spark plugs are okay, go to next step.
Check spark plugs for cracks or damage, excessive wear or improper gap. Check for carbon tracking on insulator. Replace components as necessary. After repairs, go step 9 . If components are okay, go to next step.
Check compression and perform leak down test on affected cylinder. Replace components as necessary. After performing OBD system check, go to next step. If components are okay, diagnose fuel system malfunction. See FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0301 is set, go to step 2 . If DTC P0301 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

DTC P0302: CYLINDER NO. 2 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 and P1621 not set.
Misfire total is greater than 12 counts.
Engine speed is 469-6406 RPM.
Battery voltage is 9-17 volts.
ECT 20-254°F (-7 to 123°C).
Engine run time greater than 15 seconds.
TP sensor angle has not changed more than 8 percent in one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If any other DTCs are set, diagnose DTCs as necessary before proceeding. If no other DTCs are set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 6 . If no problems are found, go to next step.
Start engine and allow it to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 2 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 2 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Install Spark Tester (J-26792) to cylinder No. 2 spark plug wire. Remove spark plug wire No. 3 from ignition coil. Connect a jumper wire between ground and ignition coil tower (where spark plug wire No. 3 was). Crank engine and check for spark. If spark is present, go to step 8 . If spark is not present, go to step 9 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 2 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 2 counter is not incrementing, go to next step.
If a repair was made after visual inspection was performed in step 3 , go to step 30 . If no problems were found in visual inspection, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Remove spark plug from No. 2 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 2 counter is incrementing properly, go to step 13 . If MISFIRE CURRENT NO. 2 counter is not incrementing properly, go to step 22 .
Remove spark plug wire from cylinder No. 2. Using DVOM, check spark plug wire resistance. If resistance is less than 3000 ohms, go to next step. If resistance is not less than 3000 ohms, go to step 23 .
Remove ignition coil from cylinder that did not have spark. Check secondary resistance of coil. If resistance is 5000-8000 ohms, go to next step. If resistance is not 5000-8000 ohms, go to step 24 .
Replace coil with a known-good coil. Crank engine and check for spark. If spark is present, go to step 24 . If spark is not present, go to next step.
Disconnect and inspect Ignition Control Module (ICM) 6-pin connector. Repair as necessary. After repairs, go to step 30 . If connector is okay, go to step 25 .
Turn ignition off. Disconnect all fuel injector connectors. Install injector test light on injector harness connector for cylinder No. 2. Crank engine and observe test light. If test light flashes, go to next step. If test light does not flash, go to step 15 .
Perform INJECTOR BALANCE TEST. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article. If injector No. 2 is okay, go to step 28 . If injector No. 2 is not okay, go to step 29 .
Remove injector test light. Connect a test light between ground and ignition feed terminal at No. 2 injector harness connector. Crank engine and observe test light. If test light is on, go to next step. If test light is off, go to step 27 .
Turn ignition off. Disconnect PCM harness connectors. With test light connected to ground, probe injector driver circuit terminal at No. 2 injector harness connector. If test light is off, go to next step. If test light is on, go to step 26 .
With test light connected to positive battery terminal, probe injector driver circuit terminal at No. 2 injector harness connector. If test light is off, go to next step. If test light is on, go to step 19 .
Inspect PCM connectors for damaged pins, corrosion and loose wires. If connectors are okay, go to step 20 . If connectors are not okay, go to step 21 .
Repair short to ground in cylinder No. 2 fuel injector driver circuit. After repairs, go to step 30 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 30 .
Repair connector or connections as necessary. After repairs, go to step 30 .
Replace spark plug. After replacing spark plug, go to step 30 .
Replace spark plug wire. After replacing spark plug wire, go to step 30 .
Replace ignition coil. After replacing ignition coil, go to step 30 .
Replace ICM. After replacing module, go to step 30 .
Repair short to voltage in cylinder No. 2 fuel injector driver circuit. After repairs, go to step 30 .
Repair open in ignition feed circuit. After repairs, go to step 30 .
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted airflow, etc.). Repair as necessary. After repairs, go to step 30 .
Replace defective fuel injector. After replacing injector, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0302. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0302: CYLINDER NO. 2 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 and P1621 not set.
Misfire total is greater than 12 counts.
Engine speed is 469-6400 RPM.
Battery voltage is 9-17 volts.
ECT 20-254°F (-7 to 123°C).
Engine run time greater than 5 seconds.
TP sensor angle has not changed more than 8 percent in one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P0200 is also set, diagnose DTC as necessary before proceeding. If DTC P0200 is not set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 22 . If no problems are found, go to next step.
Start engine and allow it to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 2 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 2 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Temporarily remove ignition coil and Ignition Control Module (ICM) assembly. Install Spark Plug Jumper Wires (J-36012). Install Spark Tester (J-26792) on spark plug jumper for cylinder No. 2. Remove spark plug boot from cylinder No. 3 at ignition coil housing. Connect a jumper wire between ground and spark plug connector at ignition coil housing (where No. 3 spark plug boot was). With remaining spark plug boots still connected, crank engine and check for spark. If spark is present, go to step 7 . If spark is not present, go to step 10 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 2 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 2 counter is not incrementing, go to step 22 .
Remove spark plug from No. 2 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 2 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 2 counter is not incrementing, go to step 9 .
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted airflow, etc.). Repair as necessary. After repairs, go to step 22 .
Replace defective spark plug. After replacing spark plug, go to step 22 .
Turn ignition off. Remove boot assemblies from affected ignition coil. Using a DVOM, check secondary resistance of coil. If resistance is less than 10,000 ohms, go to next step. If resistance is not less than 10,000 ohms, go to step 12 .
Remove ignition coil housing. Disconnect coil harness connector at ICM. Connect a test light between positive battery terminal and No. 2 and No. 3 ignition coil driver circuit terminal at ICM. Observe test light and crank engine. If test light flashes, go to step 13 . If test light does not flash, go to step 14 .
Remove ignition coil from ignition coil housing. Recheck secondary resistance of coil. If resistance is less than 10,000 ohms, go to step 15 . If resistance is not less than 10,000 ohms, go to step 16 .
Repair open or shorted ignition coil wiring harness, poor ignition coil connector or replace ignition coil, ignition coil housing or boot assembly. After repairs, go to step 22 .
Disconnect and inspect ICM 11-pin connector. Repair as necessary. After repairs, go to step 22 . If connector is okay, go to step 17 .
Replace ignition coil springs for cylinders No. 2 and 3 coil. After repairs, go to step 22 .
Replace ignition coil for cylinders No. 2 and 3. After repairs, go to step 22 .
Turn ignition off. Disconnect ICM 11-pin connector. Measure resistance between ground and each ignition control circuit terminal at ICM harness connector. If both resistances are 600-2600 ohms, go to step 19 . If any resistance is not 600-2600 ohms, go to next step.
Check for an open or short in ignition control circuit(s). Repair as necessary. After repairs, go to step 22 . If circuits are okay, go to step 20 .
Replace ICM module. After replacing module, go to step 22 .
Disconnect and inspect PCM connector terminals. Repair as necessary. After repairs, go to step 22 . If connector is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC which was set. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0302: CYLINDER NO. 2 MISFIRE DETECTED (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Misfire more than legislated limit (amount of misfire ranging from 1.0-12.5 percent.
Condition must be met for at least 5 camshaft revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current counter for this cylinder. If misfire current counter increases, go to next step. If any misfire current counter does not increase, go to step 4 .
Inspect vacuum hoses for splits, kinks and proper connections. Check throttle body and intake manifold for vacuum leaks. Check PCV valve operation and PCV system for vacuum leaks. Ensure ECM grounds are clean and secure. Ensure all injector harness connectors and spark plug wires are installed at correct locations and secure. Repair or replace as necessary. After repairs, go to step 8 . If all components and systems are okay, go to step 5 .
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0302 is set, go to next step. If DTC P0302 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using Spark Plug Tester (J-26792), check spark at affected cylinder while cranking engine. If spark is present, go to next step. If spark is not present, diagnose ignition system. See BASIC IGNITION SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Remove spark plug(s) as necessary and inspect for signs of oil or coolant fouling. Replace spark plug(s) or repair engine as necessary. If spark plugs are okay, go to next step.
Check spark plugs for cracks or damage, excessive wear or improper gap. Check for carbon tracking on insulator. Replace components as necessary. After repairs, go step 9 . If components are okay, go to next step.
Check compression and perform leak down test on affected cylinder. Replace components as necessary. After repairs, go to next step. If components are okay, diagnose fuel system malfunction. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0302 is set, repeat step 2 . If DTC P0302 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

DTC P0303: CYLINDER NO. 3 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) monitors Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to detect if engine is misfiring. PCM looks for a sudden drop in crankshaft speed. This test is executed in blocks of 100 camshaft revolution tests. It may take several tests to set a DTC. Under light misfire conditions, it may take more than one trip to set a DTC. Severe misfire will flash Malfunction Indicator Light (MIL), indicating that catalytic converter damage is possible. Conditions for setting this DTC are as follows

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 and P1621 not set.
Misfire total is greater than 12 counts.
Engine speed is 469-6406 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7 to 123°C).
TP sensor angle has not changed more than 8 percent in one second.
Engine run time is more than 15 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If any other DTCs are set, diagnose DTCs as necessary before proceeding. If no other DTCs are set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 6 . If no problems are found, go to next step.
Start engine and allow to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 3 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 3 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Install Spark Tester (J-26792) to cylinder No. 3 spark plug wire. Remove No. 2 spark plug wire from ignition coil. Connect a jumper wire between ground and ignition coil tower (where No. 2 spark plug wire was). Crank engine and check for spark. If spark is present, go to step 8 . If spark is not present, go to step 9 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 3 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 3 counter is not incrementing, go to next step.
If a repair was made after visual inspection was performed in step 3 , go to step 30 . If no problems were found in visual inspection, go to «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Remove spark plug from No. 3 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 3 counter is incrementing properly, go to step 13 . If MISFIRE CURRENT NO. 3 counter is not incrementing properly, go to step 22 .
Remove spark plug wire from No. 3 cylinder. Using DVOM, check plug wire resistance. If resistance is less than 3000 ohms, go to next step. If resistance is not less than 3000 ohms, go to step 23 .
Remove ignition coil from cylinder that did not have spark. Measure secondary resistance of coil. If resistance is 5000-8000 ohms, go to next step. If resistance is not 5000-8000 ohms, go to step 24 .
Replace coil with a known-good coil. Crank engine and check for spark. If spark is present, go to step 24 . If spark is not present, go to next step.
Disconnect and inspect Ignition Control Module (ICM) 6-pin connector. Repair as necessary. After repairs, go to step 30 . If connector is okay, go to step 25 .
Turn ignition off. Disconnect all fuel injector connectors. Install injector test light on injector harness connector for No. 3 cylinder. Crank engine and observe test light. If test light flashes, go to next step. If test light does not flash, go to step 15 .
Perform injector balance test. See appropriate SYSTEM & COMPONENT TESTING article. If No. 3 injector is okay, go to step 28 . If No. 3 injector is not okay, go to step 29 .
Remove injector test light. Connect a test light between ground and ignition feed terminal at No. 3 injector harness connector. Crank engine and observe test light. If test light is on, go to next step. If test light is off, go to step 27 .
Turn ignition off. Disconnect PCM harness connectors. With test light connected to ground, probe injector driver circuit terminal at No. 3 injector harness connector. If test light is off, go to next step. If test light is on, go to step 26 .
With test light connected to positive battery terminal, probe injector driver circuit terminal at No. 3 injector harness connector. If test light is off, go to next step. If test light is on, go to step 19 .
Inspect PCM connectors for damaged pins, corrosion and loose wires. If connectors are okay, go to step 20 . If connectors are not okay, go to step 21 .
Repair short to ground in cylinder No. 3 fuel injector driver circuit. After repairs, go to step 30 .
Replace PCM. Program replacement PCM using required equipment. After repairs, go to step 30 .
Repair connector or connections as necessary. After repairs, go to step 30 .
Replace spark plug. After replacing spark plug, go to step 30 .
Replace spark plug wire. After replacing spark plug wire, go to step 30 .
Replace ignition coil. After replacing ignition coil, go to step 30 .
Replace ICM. After replacing ICM, go to step 30 .
Repair short to voltage in cylinder No. 3 fuel injector driver circuit. After repairs, go to step 30 .
Repair open in ignition feed circuit. After repairs, go to step 30 .
Check for a basic engine problem (cam timing, throttle body leak, restricted airflow, etc.). Repair as necessary. After repairs, go to step 30 .
Replace defective fuel injector. After repairs, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0303. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0303: CYLINDER NO. 3 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) monitors Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to detect if engine is misfiring. PCM looks for a sudden drop in crankshaft speed. This test is executed in blocks of 100 camshaft revolution tests. It may take several tests to set a DTC. Under light misfire conditions, it may take more than one trip to set a DTC. Severe misfire will flash Malfunction Indicator Light (MIL), indicating that catalytic converter damage is possible. Conditions for setting this DTC

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 and P1621 not set.
Misfire total is greater than 12 counts.
Engine speed is 469-6400 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7 to 123°C).
TP sensor angle has not changed more than 8 percent in one second.
Engine run time is more than 5 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P0200 is also set, diagnose DTC as necessary before proceeding. If DTC P0200 is not set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 22 . If no problems are found, go to next step.
Start engine and allow to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 3 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 3 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Temporarily remove ignition coil and Ignition Control Module (ICM) assembly. Install Spark Plug Jumper Wires (J-36012). Install Spark Tester (J-26792) on spark plug jumper for cylinder No. 3. Remove spark plug boot from cylinder No. 2 at ignition coil housing. Connect a jumper wire between ground and spark plug connector at ignition coil housing (where No. 2 spark plug boot was). With remaining spark plug boots still connected, crank engine and check for spark. If spark is present, go to step 7 . If spark is not present, go to step 10 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 3 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 3 counter is not incrementing, go to step 22 .
Remove spark plug from No. 3 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 3 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 3 counter is not incrementing, go to step 9 .
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted airflow, etc.). Repair as necessary. After repairs, go to step 22 .
Replace defective spark plug. After repairs, go to step 22 .
Turn ignition off. Remove boot assemblies from affected ignition coil. Using a DVOM, measure secondary resistance of coil. If resistance is less than 10,000 ohms, go to next step. If resistance is not less than 10,000 ohms, go to step 12 .
Remove ignition coil housing. Disconnect coil harness connector at ICM. Connect a test light between positive battery terminal and No. 2 and 3 ignition coil driver circuit terminal at ICM. Observe test light and crank engine. If test light flashes, go to step 13 . If test light does not flash, go to step 14 .
Remove ignition coil from ignition coil housing. Recheck secondary resistance of coil. If resistance is less than 10,000 ohms, go to step 15 . If resistance is not less than 10,000 ohms, go to step 16 .
Repair open or shorted ignition coil wiring harness, poor ignition coil connector or replace ignition coil, ignition coil housing or boot assembly. After repairs, go to step 22 .
Disconnect and inspect ICM 11-pin harness connector. Repair connector as necessary. After repairs, go to step 22 . If connector is okay, go to step 17 .
Replace ignition coil springs for cylinders No. 2 and 3 coil. After repairs, go to step 22 .
Replace ignition coil for cylinders No. 2 and 3. After repairs, go to step 22 .
Turn ignition off. Disconnect ICM 11-pin connector. Measure resistance between ground and each ignition control circuit terminal at ICM harness connector. If both resistances are 600-2600 ohms, go to step 19 . If any resistance is not 600-2600 ohms, go to next step.
Check for an open or short in ignition control circuit(s). Repair as necessary. After repairs, go to step 22 . If circuits are okay, go to step 20 .
Replace ICM. After replacing ICM, go to step 22 .
Disconnect and inspect PCM connector terminals. Repair as necessary. After repairs, go to step 22 . If connector is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC which was set. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0303: CYLINDER NO. 3 MISFIRE DETECTED (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Misfire more than legislated limit (amount of misfire ranging from 1.0-12.5 percent).
Condition must be met for at least 5 camshaft revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current counter for this cylinder. If misfire current counter increases, go to next step. If any misfire current counter does not increase, go to step 4 .
Inspect vacuum hoses for splits, kinks and proper connections. Check throttle body and intake manifold for vacuum leaks. Check PCV valve operation and system for vacuum leaks. Ensure ECM grounds are clean and secure. Ensure all injector harness connectors and spark plug wires are installed at correct locations and secure. Repair as necessary. After repairs, go to step 8 . If all components and systems are okay, go to step 5 .
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0303 is set, go to next step. If DTC P0303 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using Spark Plug Tester (J-26792), check spark at affected cylinder while cranking engine. If spark is present, go to next step. If spark is not present, diagnose ignition system. See BASIC IGNITION SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Remove spark plug(s) as necessary and inspect for signs of oil or coolant fouling. Replace spark plug(s) or repair engine as necessary. If spark plugs are okay, go to next step.
Check spark plugs for cracks or damage, excessive wear or improper gap. Check for carbon tracking on insulator. Replace components as necessary. After repairs, go to step 9 . If components are okay, go to next step.
Check compression and perform leak down test on affected cylinder. Replace components as necessary. After repairs, go to next step. If components are okay, diagnose fuel system malfunction. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0303 is set, go to step 2 . If DTC P0303 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

DTC P0304: CYLINDER NO. 4 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) monitors Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to detect if engine is misfiring. PCM looks for a sudden drop in crankshaft speed. This test is executed in blocks of 100 camshaft revolution tests. It may take several tests to set a DTC. Under light misfire conditions, it may take more than one trip to set a DTC. Severe misfire will flash Malfunction Indicator Light (MIL), indicating that catalytic converter damage is possible. Conditions for setting DTC

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 and P1621 not set.
Misfire total is greater than 12 counts.
Engine speed is 469-6406 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7 to 123°C).
TP sensor angle has not changed more than 8 percent in one second.
Engine run time is more than 15 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If any other DTCs are set, diagnose DTCs as necessary before proceeding. If no other DTCs are set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repairs, go to step 6 . If no problems are found, go to next step.
Start engine and allow it to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 4 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 4 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Install Spark Tester (J-26792) to cylinder No. 4 spark plug wire. Remove No. 1 spark plug wire from ignition coil. Connect a jumper wire between ground and ignition coil tower (where No. 1 spark plug wire was). Crank engine and check for spark. If spark is present, go to step 8 . If spark is not present, go to step 9 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 4 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 4 counter is not incrementing, go to next step.
If a repair was made after visual inspection was performed in step 3 , go to step 30 . If no problems were found in visual inspection, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Remove spark plug from No. 4 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 4 counter is incrementing properly, go to step 13 . If MISFIRE CURRENT NO. 4 counter is not incrementing properly, go to step 22 .
Remove spark plug wire from No. 4 cylinder. Using DVOM, measure plug wire resistance. If resistance is less than 3000 ohms, go to next step. If resistance is not less than 3000 ohms, go to step 23 .
Remove ignition coil from cylinder that did not have spark. Measure secondary resistance of coil. If resistance is 5000-8000 ohms, go to next step. If resistance is not 5000-8000 ohms, go to step 24 .
Replace coil with a known-good coil. Crank engine and check for spark. If spark is present, go to step 24 . If spark is not present, go to next step.
Disconnect and inspect Ignition Control Module (ICM) 6-pin connector. Repair as necessary. After repairs, go to step 30 . If connector is okay, go to step 25 .
Turn ignition off. Disconnect all fuel injector connectors. Install injector test light on injector harness connector for No. 4 cylinder. Crank engine and observe test light. If test light flashes, go to next step. If test light does not flash, go to step 15 .
Perform injector balance test. See appropriate SYSTEM & COMPONENT TESTING article. If injector No. 4 is okay, go to step 28 . If injector No. 4 is not okay, go to step 29 .
Remove injector test light. Connect a test light between ground and ignition feed terminal at injector No. 4 harness connector. Crank engine and observe test light. If test light is on, go to next step. If test light is off, go to step 27 .
Turn ignition off. Disconnect PCM harness connectors. With test light connected to ground, probe injector driver circuit terminal at No. 4 injector harness connector. If test light is off, go to next step. If test light is on, go to step 26 .
With test light connected to positive battery terminal, probe injector driver circuit terminal at No. 4 injector harness connector. If test light is off, go to next step. If test light is on, go to step 19 .
Inspect PCM connectors for damaged pins, corrosion and loose wires. If connectors are okay, go to step 20 . If connectors are not okay, go to step 21 .
Repair short to ground in cylinder No. 4 fuel injector driver circuit. After repairs, go to step 30 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 30 .
Repair connector or connections as necessary. After repairs, go to step 30 .
Replace spark plug. After replacing spark plug, go to step 30 .
Replace spark plug wire. After replacing spark plug wire, go to step 30 .
Replace ignition coil. After replacing ignition coil, go to step 30 .
Replace ICM. After replacing ICM, go to step 30 .
Repair short to voltage in cylinder No. 4 fuel injector driver circuit. After repairs, go to step 30 .
Repair open in ignition feed circuit. After repairs, go to step 30 .
Check for a basic engine problem (cam timing, throttle body leak, restricted airflow, etc.). Repair as necessary. After repairs, go to step 30 .
Replace defective fuel injector. After repairs, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0304. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0304: CYLINDER NO. 4 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) monitors Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to detect if engine is misfiring. PCM looks for a sudden drop in crankshaft speed. This test is executed in blocks of 100 camshaft revolution tests. It may take several tests to set a DTC. Under light misfire conditions, it may take more than one trip to set a DTC. Severe misfire will flash Malfunction Indicator Light (MIL), indicating that catalytic converter damage is possible. Conditions for setting DTC

DTCs P0106, P0107, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0171, P0172, P0325, P0335, P0341, P0342, P0404, P0405, P0502, P0503, P0506, P0507, P0601, P0740, P0742, P1133, P1404 and P1621 not set.
Misfire total is greater than 12 counts.
Engine speed is 469-6400 RPM.
Battery voltage 9-17 volts.
ECT 20-254°F (-7 to 123°C).
TP sensor angle has not changed more than 8 percent in one second.
Engine run time greater than 15 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If DTC P0200 is also set, diagnose that DTC as necessary before proceeding. If DTC P0200 is not set, go to next step.
Perform a visual inspection of the following. Check vacuum hoses for splits, kinks and proper routing. Check for leaks at throttle body, intake manifold, EGR valve and PCV system. Check PCM grounds for proper connection. Check injector harness connectors for proper installation. Repair as necessary. After repair is completed, go to step 22 . If no problems were found, go to next step.
Start engine and allow it to idle. Using scan tool, select MISFIRE DATA LIST function and monitor MISFIRE CUR. COUNTERS (one counter per cylinder). If MISFIRE CURRENT NO. 4 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 4 counter is not incrementing, go to step 6 .
Turn ignition off. Disconnect fuel injector harness connector. Temporarily remove ignition coil and Ignition Control Module (ICM) assembly. Install Spark Plug Jumper Wires (J-36012). Install Spark Tester (J-26792) on spark plug jumper for cylinder No. 4. Remove spark plug boot from cylinder No. 1 at ignition coil housing. Connect a jumper wire between ground and spark plug connector at ignition coil housing (where No. 1 spark plug boot was). With remaining spark plug boots still connected, crank engine and check for spark. If spark is present, go to step 7 . If spark is not present, go to step 10 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MISFIRE CURRENT NO. 4 counter is incrementing, go to step 5 . If MISFIRE CURRENT NO. 4 counter is not incrementing, go to step 22 .
Remove spark plug from No. 4 cylinder. Replace spark plug with a known-good spark plug. Reconnect fuel injection harness connector. Operate vehicle within misfire conditions as recorded in FREEZE FRAME. If MISFIRE CURRENT NO. 4 counter is incrementing, go to next step. If MISFIRE CURRENT NO. 4 counter is not incrementing, go to step 9 .
Check for a basic engine problem (compression, cam timing, throttle body leak, restricted air flow. etc.). Repair as necessary. After repairs, go to step 22 .
Replace defective spark plug. After replacing spark plug, go to step 22 .
Turn ignition off. Remove boot assemblies from affected ignition coil. Using a DVOM, measure secondary resistance of coil. If resistance is less than 10,000 ohms, go to next step. If resistance is not less than 10,000 ohms, go to step 12 .
Remove ignition coil housing. Disconnect coil harness connector at ICM. Connect a test light between positive battery terminal and No. 1 and 4 ignition coil driver circuit terminal at ICM. Crank engine and observe test light. If test light flashes, go to step 13 . If test light does not flash, go to step 14 .
Remove ignition coil from ignition coil housing. Recheck secondary resistance of coil. If resistance is less than 10,000 ohms, go to step 15 . If resistance is not less than 10,000 ohms, go to step 16 .
Repair open or shorted ignition coil wiring harness, poor ignition coil connector or replace ignition coil, ignition coil housing or boot assembly. After repairs, go to step 22 .
Disconnect and inspect ICM 11-pin harness connector. Repair connector as necessary. After repairs, go to step 22 . If connector is okay, go to step 17 .
Replace ignition coil springs for cylinders No. 1 and 4 coil. After repairs, go to step 22 .
Replace ignition coil for cylinders No. 1 and 4. After repairs, go to step 22 .
Turn ignition off. Disconnect ICM 11-pin harness connector. Check resistance between ground and each ignition control circuit terminal at ICM harness connector. If both resistances are 600-2600 ohms, go to step 19 . If any resistance is not 600-2600 ohms, go to next step.
Check for an open or short in ignition control circuit(s). Repair as necessary. After repairs, go to step 22 . If circuits are okay, go to step 20 .
Replace ICM. After replacing ICM, go to step 22 .
Disconnect and inspect PCM connector terminals. Repair as necessary. After repairs, go to step 22 . If connector is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC which was set. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0304: CYLINDER NO. 4 MISFIRE DETECTED (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Misfire more than legislated limit (amount of misfire ranging from 1.0-12.5 percent.
Condition must be met for at least 5 camshaft revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current counter for this cylinder. If misfire current counter increases, go to next step. If any misfire current counter does not increase, go to step 4 .
Inspect vacuum hoses for splits, kinks and proper connections. Check throttle body and intake manifold for vacuum leaks. Check PCV valve operation and PCV system for vacuum leaks. Ensure ECM grounds are clean and secure. Ensure all injector harness connectors and spark plug wires are installed at correct locations and secure. Repair or replace as necessary. After repairs, go to step 8 . If all components and systems are okay, go to step 5 .
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0304 is set, go to next step. If DTC P0304 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using Spark Plug Tester (J-26792), check spark at affected cylinder while cranking engine. If spark is present, go to next step. If spark is not present, diagnose ignition system. See BASIC IGNITION SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Remove spark plug(s) as necessary and inspect for signs of oil or coolant fouling. Replace spark plug(s) or repair engine as necessary. If spark plugs are okay, go to next step.
Check spark plugs for cracks or damage, excessive wear or improper gap. Check for carbon tracking on insulator. Replace components as necessary. After repairs, go step 9 . If components are okay, go to next step.
Check compression and perform leak down test on affected cylinder. Replace components as necessary. After repairs, go to next step. If components are okay, diagnose fuel system malfunction. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0304 is set, go to step 2 . If DTC P0304 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

DTC P0305: CYLINDER NO. 5 MISFIRE DETECTED (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Misfire is more than legislated limit (amount of misfire ranging from 1.0-12.5 percent.
Condition must be met for at least 5 camshaft revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current counter for this cylinder. If misfire current counter increases, go to next step. If any misfire current counter does not increase, go to step 4 .
Inspect vacuum hoses for splits, kinks and proper connections. Check throttle body and intake manifold for vacuum leaks. Check PCV valve operation and PCV system for vacuum leaks. Ensure ECM grounds are clean and secure. Ensure all injector harness connectors and spark plug wires are installed at correct locations and secure. Repair or replace as necessary. After repairs, go to step 8 . If all components and systems are okay, go to step 5 .
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0305 is set, go to next step. If DTC P0305 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using Spark Plug Tester (J-26792), check spark at affected cylinder while cranking engine. If spark is present, go to next step. If spark is not present, diagnose ignition system. See BASIC IGNITION SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Remove spark plug(s) as necessary and inspect for signs of oil or coolant fouling. Replace spark plug(s) or repair engine as necessary. If spark plugs are okay, go to next step.
Check spark plugs for cracks or damage, excessive wear or improper gap. Check for carbon tracking on insulator. Replace components as necessary. After repairs, go step 9 . If components are okay, go to next step.
Check compression and perform leak down test on affected cylinder. Replace components as necessary. After repairs, go to next step. If components are okay, diagnose fuel system malfunction. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0305 is set, go to step 2 . If DTC P0305 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

DTC P0306: CYLINDER NO. 6 MISFIRE DETECTED (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Misfire is more than legislated limit (amount of misfire ranging from 1.0-12.5 percent.
Condition must be met for at least 5 camshaft revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and idle engine. Using scan tool, monitor misfire current counter for this cylinder. If misfire current counter increases, go to next step. If any misfire current counter does not increase, go to step 4 .
Inspect vacuum hoses for splits, kinks and proper connections. Check throttle body and intake manifold for vacuum leaks. Check PCV valve operation and PCV system for vacuum leaks. Ensure ECM grounds are clean and secure. Ensure all injector harness connectors and spark plug wires are installed at correct locations and secure. Repair or replace as necessary. After repairs, go to step 8 . If all components and systems are okay, go to step 5 .
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0306 is set, go to next step. If DTC P0306 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Using Spark Plug Tester (J-26792), check spark at affected cylinder while cranking engine. If spark is present, go to next step. If spark is not present, diagnose ignition system. See BASIC IGNITION SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Remove spark plug(s) as necessary and inspect for signs of oil or coolant fouling. Replace spark plug(s) or repair engine as necessary. If spark plugs are okay, go to next step.
Check spark plugs for cracks or damage, excessive wear or improper gap. Check for carbon tracking on insulator. Replace components as necessary. After repairs, go step 9 . If components are okay, go to next step.
Check compression and perform leak down test on affected cylinder. Replace components as necessary. After repairs, go to next step. If components are okay, diagnose fuel system malfunction. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0306 is set, go to step 2 . If DTC P0306 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

DTC P0322: IGNITION CONTROL (IC) MODULE 4X REFERENCE CIRCUIT-NO FREQUENCY (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

PCM check for camshaft pulses being received without 4X reference pulses. Conditions for setting DTC

DTCs P0340 and P1376 not set.
A CAM sensor signal has been received in the last 4 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Using scan tool, check if DTC P1376 is also present. If DTC P1376 is present, diagnose this DTC first. If DTC P1376 is not present, go to next step.
Start and idle engine. Using scan tool, select DTC INFO then FAIL THIS IGN. in DTC mode. If DTC P0322 is indicated as current, go to next step. If DTC P0322 does not indicate as current, go to step 9 .
Store fluid life data as indicated on scan tool. Turn ignition off and wait 30 seconds, then disconnect PCM harness connector C2. Disconnect Ignition Control (IC) module harness connector C4. Using DVOM, check resistance between ground and IC module harness connector fuel control circuit terminal. If resistance is 10,000 ohms or greater, go to next step. If resistance is not 10,000 ohms or greater, go to step 9 .
Check resistance between PCM harness connector fuel control circuit terminal and IC module harness connector C4 fuel control circuit terminal. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 13 .
Turn ignition on. Check voltage to ground at IC module harness connector C4 fuel control circuit terminal. If voltage reading is 0.5 volt or less, go to next step. If voltage reading is not 0.5 volt or less, go to step 14 .
Reconnect IC module harness connector C4. Check voltage to ground at PCM harness connector C4 cam signal circuit terminal. If voltage reading is 4.1 volts or greater, go to next step. If voltage reading is not 4.1 volts or greater, go to step 15 .
Turn ignition off. Reconnect PCM harness connector C2. Using 6-Pin IC module diagnostic jumpers, jumper the following IC module connector C4 terminals to the following module terminals: C4 Terminal "A" To Module Pin "A" C4 Terminal "B" To Module Pin "B" C4 Terminal "C" To Module Pin "C" C4 Terminal "D" To Module Pin "D" C4 Terminal "E" To Module Pin "E" C4 Terminal "F" To Module Pin "F" Set DVOM to amp scale. Connect DVOM between terminal "C" jumper. Start engine and check frequency in terminal "C" jumper. If frequency is 30-100 Hz, go to step 16 . If frequency is not 30-100 Hz, go to step 15 .
Using DVOM, check FAILURE REC. for DTC P0322 and note MAP value when DTC was set. If MAP value is greater than 80 kPa, go to next step. If MAP value is not greater than 80 kPa, go to step 11 .
Check for intermittent short to voltage or for Electromagnetic Interference (EMI) on cam sensor wires. EMI can be caused by wiring being too close to spark plug wires or high power transmitters operating within vicinity. DTC can also be set by battery charger. Repair or correct problem as necessary. If circuits are okay and if the other conditions are not present, fault is not present.
Check for intermittent open or short in fuel control circuit between PCM and IC module connectors. Also check circuit to DIS fuse. Repair as necessary.
Repair short to ground in fuel control circuit.
Repair open in fuel control circuit.
Repair short to voltage in fuel control circuit.
Replace IC module.
Check terminal contact at fuel control circuit terminal at PCM harness connector. Repair as necessary. If terminal contact is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment.

DTC P0325: KNOCK SENSOR CIRCUIT (2.2L "J" BODY & "S" SERIES & 2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) is used to detect engine detonation. PCM will retard spark timing based on signals from KS module. The KS produces an AC signal voltage that is sent to the KS module. The amount of AC voltage produced is proportional to the amount of knock. Conditions for setting this DTC are as follows

Engine run time is greater than 20 seconds.
ECT is greater than 131°F (56°C).
KS instantaneous voltage is less than one volt.
Engine speed is greater than 2200 RPM.
MAP is greater than 60 kPa.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start engine. Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Operate engine at 10 percent throttle angle. Check Malfunction Indicator Light (MIL). If MIL is on, go to step 4 . If MIL is off, go to next step.
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If MIL is on, go to next step. If MIL is off, go to step 12 .
While listening to engine, increase and decrease engine RPM. If an audible noise or knock is present, go to next step. If no audible noise or knock is present, go to step 6 .
Repair cause of engine noise or knock. After repairs, go to step 12 .
Turn ignition off. Disconnect PCM harness connectors. Check resistance between ground and signal circuit terminal at PCM connector. If resistance is 90-110 k/ohms, go to next step. If resistance is not 90-110 k/ohms, go to step 9 .
Check KS signal circuit for poor connection at PCM. Repair as necessary. After repairs, go to step 12 . If circuit is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 12 .
Check KS harness connector. Repair as necessary. After repairs, go to step 12 . If connector is okay, go to next step.
Check knock sensor circuit for open, short to ground or short to voltage. Repair as necessary. After repairs, go to step 12 . If circuits are okay, go to next step.
Replace KS. After replacing sensor, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter this DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

Check knock sensor for proper connection. A loose or over-torqued knock sensor can cause DTC to set.

DTC P0325: KNOCK SENSOR CIRCUIT-BANK 1 (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) system is used to detect engine detonation. ECM will retard spark timing based on signals from KS module. Knock sensors produce an AC voltage signal that is sent to KS module. Amount of AC voltage signal produced is proportional to amount of knock.

An operating engine produces a normal amount of engine mechanical vibration (noise). Knock sensors will produce an AC voltage signal from this noise. When an engine is operating, ECM will learn minimum and maximum frequency of noise the engine produces. When ECM determines that this frequency is less than or greater than expected amount, a knock sensor DTC will set. Conditions for setting DTC

Knock sensor signal is lower than specified values. See «KNOCK SENSOR SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) table.

Engine Speed (RPM)	Reference Signal (mV)
0	1.83
800	2.44
1600	3.66
2000	4.27
2400	5.49
2800	6.71
3200	8.54
3600	10.38
4000	12.82
4400	15.26
4800	18.31
5200	22.58
5600	28.69
5920	39.06
6200	39.06
6400	39.06

KNOCK SENSOR SPECIFICATIONS

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate at greater than 2000 RPM and as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0325 is set, go to next step. If DTC P0325 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect knock sensor connector. Disconnect ECM connector located in engine compartment relay center. Check for poor connections or terminal tension at ECM and knock sensor connectors. Repair as necessary. After repairs, go to step 14 . If connections and terminals are okay, go to next step.
Turn ignition on, with engine off. Using DVOM, measure voltage between ground and KS signal circuit at ECM harness connector. If any voltage is present, go to step 9 . If no voltage is present, go to next step.
Using DVOM, check harness continuity of KS signal circuit. If continuity exists, go to next step. If continuity does not exist, go to step 11 .
Using DVOM, check harness continuity between ground and KS sensor signal circuit. If continuity exists, go to step 10 . If continuity does not exist, go to next step.
Turn ignition off. Reconnect ECM connector. Turn ignition on, with engine off. Using test light connected to battery voltage, probe KS harness connector ground circuit. If test light is on, go to next step. If test light is off, go to step 12 .
Using test light connected to battery voltage, probe KS sensor shielding on wiring harness. If test light is on, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If test light is off, go to step 13 .
Repair short to voltage is signal circuit. After repairs, go to step 14 .
Repair short to ground in signal circuit. After repairs, go to step 14 .
Repair open or high resistance in signal circuit. After repairs, go to step 14 .
Repair open or high resistance in ground circuit. After repairs, go to step 14 .
Repair knock sensor shield circuit. After repairs, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate at greater than 2000 RPM and as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0325 is set, repeat step 2 . If DTC P0325 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

Check knock sensor for proper installation. A knock sensor that is loose or over tightened may cause this DTC to set.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) module is integrated in PCM circuit. KS module reads KS to determine if excessive detonation (knock) is present. If excessive knock is present, PCM will retard timing until knock goes away. When KS module is missing or malfunctioning, PCM will set DTC P0325. Conditions for setting DTC

No CKP, CMP, ECT, MAF, TP or VSS DTCs set.
Engine speed 1000-5000 RPM.
Throttle angle greater than 10 percent.
Engine load greater than 55 percent.
ECT greater than 167°F (75°C).
Maximum retard less than 15 degrees.
System voltage greater than 9 volts.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine knock can be heard, repair engine mechanical problem before proceeding with test. Operate vehicle within conditions required to set DTC. Using scan tool, select DTC, SPECIFIC function and enter this DTC. If scan tool display shows DTC P0325 FAILED THIS IGN, go to step 4 . If scan tool display does not show DTC P0325 FAILED THIS IGN, go to next step.
Turn ignition on, engine off. Read and record FAILURE RECORDS data for DTC P0325. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0325 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0325 FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, read and record FAILURE RECORDS DATA, and clear DTCs. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, select SPECIFIC DTC INFO for DTC P0325. Monitor scan tool until DTC P0325 test runs. If scan tool displays DTC P0325 FAILED THIS IGN, repeat step 2 . If scan tool does not display DTC P0325 FAILED THIS IGN, system is okay.

Check for faulty connection at PCM. Check KS connector for proper connection or damage.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (3.5L "W" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) module is located in PCM. KS module monitors both knock sensors to determine if detonation is present. If excessive knock is present, PCM will retard timing until knock goes away. When KS module is missing or malfunctioning, KS circuit voltage going to PCM will go low. PCM interprets this low signal as spark knock.

Conditions for running DTC are: no AIR, VSS, TP, CKP, MAF or ECT sensor DTCs set, engine speed is 1000-3000 RPM, throttle angle is greater than 15 percent, engine load is greater than 45 percent, coolant temperature is greater than 149°F (65°C), maximum spark retard is less than 15 degrees, system voltage greater than 9 volts, and engine run time is greater than 30 seconds.

DTC will set when PCM detects a malfunction in the integrated knock sensor diagnostic circuitry which will not allow proper diagnosis of knock sensor circuit.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Check for proper harness connection at PCM. Ensure PCM grounds are tight and clean. Repair as necessary. After repairs, go to step 4 . If PCM connections and ground are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for faulty connection at PCM. Check KS connector for proper connection or damage.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) module is located in PCM and is replaceable. KS module reads KS to determine if excessive detonation (knock) is present. If excessive knock is present, PCM will retard timing until knock goes away. When KS module is missing or malfunctioning, PCM will set DTC P0325. Conditions for setting DTC

System voltage greater than 9 volts.
PCM detects problem with KS module causing knock to be indicated continuously.
Conditions present for up to 2.5 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine knock can be heard, repair engine mechanical problem before proceeding with test. Operate vehicle within conditions required to set DTC. Using scan tool, select DTC, SPECIFIC function and enter DTC P0325. If scan tool displays DTC P0325 FAILED THIS IGN, go to step 4 . If scan tool does not display DTC P0325 FAILED THIS IGN, go to next step.
Turn engine off. Turn ignition on, engine off. Read and record FAILURE RECORDS data for DTC P0325. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0325 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0325 FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, read and record FAILURE RECORDS DATA, and clear DTCs. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, select SPECIFIC DTC INFO for DTC P0325. Monitor scan tool until DTC P0325 test runs. If scan tool displays DTC P0325 FAILED THIS IGN, return to step 2 . If scan tool does not display DTC P0325 FAILED THIS IGN, repair is complete.

Check for faulty connection at PCM. Check KS connector for damage. Ensure KS is installed properly.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

The PCM stores a calibrated time that it considers to be a valid spark knock duration. If PCM sees a knock event that is longer in duration that the acceptable stored time, DTC will set.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition off. Remove Knock Sensor (KS) module from PCM. Install a known-good KS module. Using FAILURE REC. snapshot data from scan tool, duplicate conditions when DTC originally set. Using scan tool, select DTC INFO then FAIL THIS IGN. function. If DTC P0325 resets, go to next step. If DTC P0325 does not reset, go to step 4 .
Replace PCM. Program replacement PCM using required equipment.
Replace KS module.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

VCM utilizes knock sensors to detect engine detonation, allowing VCM to retard Ignition Control (IC) spark timing based on knock sensor signal received. Knock Sensor (KS) circuitry within sensor pulls down VCM-supplied 5-volt DC signal, so that under a no-knock condition signal on KS, circuit measures about 1.3 volts. Sensor produces an AC signal that rides on DC signal. Signal amplitude and frequency are dependent upon amount of knock experienced.

VCM contains a replaceable KS module. KS module contains circuitry that allows VCM to utilize KS signal and diagnose knock sensors and circuitry. VCM will set DTC if KS module is missing or faulty causing a continuous knock condition. Conditions for setting DTC

DTC P0327 is not set.
Engine has been running for at least 120 seconds.
System voltage is greater than 10 volts but less than 17.1 volts.
VCM detects a problem with KS module circuitry that causes a continuous knock condition.
Conditions are present for up to 0.5 second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine knock can be heard, repair mechanical problem before proceeding. Install scan tool. Operate vehicle within the conditions for setting this DTC. Using scan tool, monitor SPECIFIC DTC for this DTC. If scan tool indicates that this DTC FAILED THIS IGN, go to step 4 . If scan tool does not indicate that this DTC FAILED THIS IGN, go to next step.
Turn ignition on, with engine off. Using scan tool, review and record FAILURE RECORDS data. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, monitor SPECIFIC DTC for this DTC. If scan tool indicates that this DTC FAILED THIS IGN, go to next step. If scan tool does not indicate that this DTC FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Check KS signal circuit for incorrect routing near secondary wires and repair as necessary. If a problem is found, go to step 8 . If no problem is found, go to next step.
Check if KS module is fully seated or incorrectly installed and repair as necessary. If a problem is found, go to step 8 . If no problem is found, go to next step.
Replace KS module. Operate vehicle within the conditions for setting this DTC. Using scan tool, monitor SPECIFIC DTC for this DTC. If scan tool indicates that this DTC FAILED THIS IGN, go to next step. If scan tool does not indicate that this DTC FAILED THIS IGN, go to step 8 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for poor connections at VCM. Inspect KS module connector for backed-out terminals, broken locks, and improperly formed or damaged terminals. Check for damaged or improperly installed KS module. Check for bent pins, deformed terminals, or if KS module is fully seated. Check knock sensor torque specification. Specification should be 14 ft. lbs. (19 N.m). Checking FAILURE RECORDS vehicle mileage data since diagnostic test last failed can be useful in determining how often condition causing DTC to set occurs. This may assist in diagnosis.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC P0327 is not active.
Engine run time at least 120 seconds.
System voltage is greater than 10 volts but less than 17.1 volts.
VCM detects a problem with KS module circuitry that causes a continuous knock condition.
Conditions present for up to 0.5 second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine knock can be heard, repair mechanical problem before proceeding. Install scan tool. Operate vehicle within the conditions for setting this DTC. Using scan tool, monitor SPECIFIC DTC for this DTC. If scan tool indicates that this DTC FAILED THIS IGN, go to step 4 . If scan tool does not indicate that this DTC FAILED THIS IGN, go to next step.
Turn ignition on, with engine off. Using scan tool, review and record FAILURE RECORDS data. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, monitor SPECIFIC DTC for this DTC. If scan tool indicates that this DTC FAILED THIS IGN, go to next step. If scan tool does not indicate that this DTC FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Check KS signal circuit for incorrect routing near secondary wires and repair as necessary. If a problem is found, go to step 8 . If no problem is found, go to next step.
Check if KS module is fully seated or incorrectly installed and repair as necessary. If a problem is found, go to step 8 . If no problem is found, go to next step.
Replace KS module. Operate vehicle within the conditions for setting this DTC. Using scan tool, monitor SPECIFIC DTC for this DTC. If scan tool indicates that this DTC FAILED THIS IGN, go to next step. If scan tool does not indicate that this DTC FAILED THIS IGN, go to step 8 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Conditions for running DTC are: engine speed is 1500-3000 RPM, throttle angle is greater than 0.5 percent, coolant temperature is greater than 140°F (60°C), MAP less than 44 kPa, and engine run time is greater than 20 seconds.

DTC will set when PCM detects a malfunction in the integrated knock sensor system or circuits and with conditions present for 20 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Replace PCM. Program replacement PCM using required equipment. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for faulty connection at PCM. Check KS connector for proper connection or damage.

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine speed is 1500-3500 RPM.
Engine coolant temperature greater than 158°F (70°C).
TP sensor angle greater than 0.5 percent.
Engine operating for greater than 20 seconds.
A malfunction with KS module or circuits to module are faulty.
Conditions present for 3 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Replace PCM. Program replacement PCM using required equipment. After repair is completed, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0325. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

If diagnostic test does not run, check if KS module is missing or faulty KS module circuit. Check KS module terminals for corrosion. If corrosion is present, check module access cover seal for cuts or nicks.

DTC P0326: KNOCK SENSOR CIRCUIT-EXCESSIVE KNOCK PRESENT (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock sensor cannot differentiate between spark knock and other similar engine noises. When knock sensor cannot eliminate noise by retarding spark timing, DTC will set. The knock circuit is continuously monitored for these parameters.

DTC indicates excessive engine noise usually caused by something else besides spark knock. It does not indicate a faulty knock sensor circuit subsystem. Knock could be caused by valve lifter noise, belt tensioner, loose bracket, low octane fuel, heavy load or scuffed piston/cylinder bore.

PCM has the ability to learn spark retard. If knock is present long enough to fill the mid, hi and low spark compensating cells a reduced power condition may result due to maximum spark retard.

The spark compensating cells will eventually learn back (to 0) when knock condition is corrected. The spark compensating cells may be viewed on the scan tool's spark table. The stored spark retard (hi, mid and low table values) are adjusted according to start up coolant temperature. If coolant temperature is

Less than 46°F (8°C) - Table value is 0.
Less than 133°F (56°C) - Table value is 75 percent of stored learned values.
Greater than 219°F (104°C) - Use stored value.

DTC P0326: KNOCK SENSOR CIRCUIT-EXCESSIVE SPARK RETARD (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC will set if knock system is otherwise functioning normally, but is detecting excessive knock. This may be due to a noisy engine producing excessive mechanical vibrations from piston slap, valve closures, etc. Excessive knock could also be produced by very low octane fuel.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start engine. Observe if engine is producing excessive mechanical noise. If excessive noise is observed, go to next step. If excessive noise is not observed, go to step 4 .
Locate and repair source of noise.
Use higher octane fuel. If higher octane fuel is not available, go to next step. If higher octane fuel is used, go to step 6 .
Using scan tool, select MORE, then select SERV. SPARK under MISC. TEST function. Activate SERV. SPARK (this can lower base timing from 10 degrees to 6 degrees BTDC). Retard base timing in 2 degrees BTDC increments as needed. SERV. SPARK will stay at set reading until changed with scan tool or when power to PCM is disconnected.
Fill fuel tank with premium fuel. Drive vehicle for about 15 minutes, allowing PCM to adjust to the premium fuel.

DTC P0327: KNOCK SENSOR CIRCUIT MALFUNCTION (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock sensor produces an output voltage (AC) based on mechanical engine vibration. PCM will retard the electronic spark timing on the signal being received. The amplitude and signal frequency is dependent upon the knock level. Upon diagnosis of the sensor circuit, PCM will learn a minimum engine noise level at idle and compare to a noise level at around 2000-3000 RPM. This change does not necessarily mean spark knock is detected, but the sensor is giving the PCM a voltage signal based on the level of noise it sees. When PCM monitors the circuit, it will set a DTC if there is no change in output from the knock sensor between idle and 2000-3000 RPM.

DTC will set if there is an open or fault in the knock sensor circuit when the PCM has learned minimum noise level at idle for 5 seconds and does not detect a change in noise level between 2500-3500 RPM for 5 seconds, coolant temperature is greater than 149°F (65°C), engine run time is greater than 10 seconds or vehicle is moving to reach 2500-3500 RPM.

Start and idle engine. Connect scan tool. Using scan tool, observe KS active noise counter while accelerating engine. If noise channel value increases with RPM, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If noise channel value does not increase with RPM, go to next step.
Turn engine off. Disconnect KS harness connector. Turn ignition on, with engine off. Connect test light battery voltage. Using test light, momentarily touch and release KS harness connector terminal. Repeat several times while observing noise channel on scan tool. If noise channel value changes, check for terminal tightness at sensor or faulty sensor. If noise channel value does not change, go to next step.
If test light illuminates when probing KS harness connector terminal, go to next step. If test light does not illuminate when probing KS harness connector terminal, check for open in circuit, terminal tightness at PCM or faulty PCM.
Turn ignition off. Disconnect PCM harness connector J3. Turn ignition on. If test light now illuminates, repair short to ground in KS circuit. If test light does not illuminate, replace PCM.

When attempting to diagnose an intermittent problem, use scan tool to review malfunction history information. This data can be used to duplicate a problem. KS sensor resistance should be about 100,000 ohms at 70°F (21C°). Use only specified replacement sensor. Previous model year sensor has different internal resistor.

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) is used to detect engine detonation (knock). If excessive knock is present, PCM will retard timing until knock goes away. When KS module in PCM determines that an abnormally high noise channel voltage exists, PCM will set DTC P0327. Conditions for setting DTC

No CMP, CKP, ECT, MAF, TP or VSS sensor DTCs set.
ECT greater than 167°F (75°C).
TP angle greater than 10 percent.
Engine speed is 1000-5000 RPM.
System voltage greater than 9 volts.
PCM detects a KS signal voltage within the calculated average voltage range.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Operate vehicle within conditions required to set DTC. Using scan tool, select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to step 4 . If scan tool does not display DTC P0327 FAILED THIS IGN, go to next step.
Turn engine off. Turn ignition on, engine off. Read and record FAILURE RECORDS data for DTC P0327. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0327 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0327 FAILED THIS IGN, go to «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect PCM and KS connector. Check KS signal circuit between PCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 7 . If circuit is okay, go to next step.
Check KS signal circuit for poor terminal connection at KS. Repair as necessary. After repairs, go to step 7 . If connection is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Read and record FAILURE RECORDS data for DTC P0327. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0327 FAILED THIS IGN, repeat step 2 . If scan tool does not display DTC P0327 FAILED THIS IGN, system is okay.

Check for faulty connection at PCM or KS. Ensure KS harness is not routed too close to high-voltage wires, such as spark plug cables, ignition coils or other high-voltage components.

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (3.5L "W" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC will set when PCM detects that knock sensor voltage remains within the calculated average voltage range.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition off for 15 seconds. Start and operate engine within conditions for running this DTC. Using scan tool, monitor SPECIFIC DTC for DTC P0327 until this DTC test runs. If scan tool indicates that this DTC failed this ignition, go to step 4 . If scan tool does not indicate that this DTC failed this ignition, go to next step.
Turn ignition off for 15 seconds, then turn ignition on. Using scan tool, read and record FAILURE RECORDS data. Operate vehicle under the same conditions indicated in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC until DTC P0327 runs. If scan tool indicates that DTC P0327 failed this ignition, go to next step. If scan tool does not indicate that DTC P0327 failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition on. Disconnect PCM and knock sensor harness connectors. Check knock sensor circuit for open, short to ground or short to voltage. Repair as necessary. After repairs, go to step 7 . If circuit is okay, go to next step.
Check knock sensor signal circuit for poor terminal connector at sensor and PCM. Repair as necessary. After repairs, go to step 7 . If terminal connections are okay, go to next step.
Replace knock sensor. After replacing knock sensor, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for faulty connection at PCM. Check KS connector for proper connection or damage.

DTC P0327: KNOCK SENSOR CIRCUIT-BANK 1 (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) is used to detect engine detonation (knock). When KS module in PCM determines that an abnormally high noise channel voltage exists, PCM will set DTC P0327. Conditions for setting DTC

No active CKP, ECT, MAF, TP or VSS sensor DTCs set.
ECT greater than 167°F (75°C).
Engine load is greater than 3 percent.
TP angle greater than 3 percent.
Engine speed is 1000-4000 RPM.
Maximum system spark retard less than 15 percent.
System voltage greater than 9 volts.
PCM detect a KS 1 signal voltage within the calculated average voltage range.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine knock can be heard, repair mechanical problem before proceeding with test. After repairs, operate vehicle within conditions required to set DTC. Using scan tool, select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to step 4 . If scan tool does not display DTC P0327 FAILED THIS IGN, go to next step.
Turn ignition on, engine off. Read and record FAILURE RECORDS data for DTC P0327. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0327 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0327 FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect KS No. 1 connector. Using a DVOM, check voltage between engine ground and terminal at each KS. If voltage reading is 5 volts, go to next step. If voltage reading is not 5 volts, go to step 8 .
Connect DVOM to bank 1 KS terminal and ground. Select 2-volt AC scale on DVOM. Start and operate engine at idle. Observe DVOM. If voltage reading is indicated on DVOM, go to step 9 . If voltage reading is not indicated, go to next step.
Turn ignition off. With DVOM still connected between KS terminal and engine ground, tap on engine while observing DVOM. If any signal is present, go to next step. If signal is not present, go to step 9 .
Check KS harness connector for incorrect routing or faulty terminal connection at KS. Repair as necessary. After repairs, go to step 12 . If no problem is found, go to step 10 .
Turn ignition off. Disconnect PCM harness connectors. Turn ignition on and check KS signal circuit between PCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 12 . If no problem is found, go to step 10 .
Replace KS. After replacing sensor, go to step 12 .
Turn ignition off. Disconnect PCM harness connectors. Check KS signal circuit for proper terminal connection at PCM. Repair or replace terminal as necessary. After repairs, go to step 12 . If terminal is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Read and record FAILURE RECORDS data for DTC P0327. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0327 FAILED THIS IGN, return to step 2 . If scan tool does not display DTC P0327 FAILED THIS IGN, repair is complete.

Check for faulty connection at PCM. Check KS and PCM connectors for damage. Ensure KS harness is not routed too close to high-voltage wires, such as spark plug cables, ignition coils or other high-voltage components. Ensure KS is installed properly.

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

During engine operation, Knock Sensor (KS) will detect background noise on its circuits. PCM monitors this noise and compares the amount of noise it monitors to the amount of noise it expects to see. DTC will set of knock sensor background noise is less than an expected learned value at a given RPM and TP sensor range for a given period of time. Conditions for setting DTC

Ignition voltage at least 10 volts.
Coolant temperature at least 104°F (40°C).
Throttle position at least 4.8 degrees.
Engine speed at least 3000 RPM.
Battery voltage at least 11 volts.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Disconnect knock sensor/starter solenoid harness connector (on right side of engine compartment). Set DVOM to 400 mV AC scale. Check frequency (Hertz) at KS connector terminal. Tap on engine block with a non-metallic object. If frequency fluctuates while tapping block, go to step 5 . If frequency does not fluctuate, go to next step.
Remove intake manifold. Disconnect knock sensor harness connector. Using DVOM, check frequency (Hertz) directly at knock sensor. Tap on engine block with a non-metallic object. If frequency fluctuates while tapping on block, go to next step. If frequency does not fluctuate, go to step 9 .
Repair open or short to ground in circuit between knock sensor and knock sensor/starter solenoid harness connector.
Reconnect knock sensor/starter solenoid harness connector. Using scan tool, select STORE INFO. and save data stored when DTC was set. Store fluid life value as indicated on scan tool. Turn ignition off and wait 30 seconds, then disconnect PCM harness connector C2. Using DVOM, check frequency at PCM harness connector knock signal circuit, while tapping on engine block. If frequency fluctuates while tapping on block, go to step 7 . If frequency does not fluctuate, go to next step.
Repair open or short to ground in circuit between PCM connector C2 and knock sensor/starter solenoid harness connector terminal.
Reconnect PCM harness connector. Using scan tool, select FAILURE REC. and note conditions under which the DTC set. Operate vehicle with engine temperature at about 104°F (40°C), TP sensor at 4.8 degrees, engine speed at 3000 RPM and ensure battery voltage is at least 11 volts. If DTC resets, go to next step. If DTC does not reset, fault is not present. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Check terminal contact at PCM connector C2 knock sensor signal circuit. Repair as necessary. If terminal contact is okay, go to step 11 .
Check terminal contact at knock sensor. Repair as necessary. If terminal contact is okay, go to next step.
Replace knock sensor.
Replace PCM. Program replacement PCM using required equipment.

Check for an intermittent open or short in knock sensor circuit.

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

VCM utilizes knock sensors to detect engine detonation, allowing VCM to retard Ignition Control (IC) spark timing based on knock sensor signal received. Knock Sensor (KS) circuitry within sensor pulls down VCM-supplied 5-volt signal, so that under a no knock condition signal on KS circuit measures about 1.3 volts. Sensor produces an AC signal that rides on 1.3 volts DC. Signal amplitude and frequency are dependent upon amount of knock experienced.

VCM determines if knock is present by comparing signal level on KS circuit with voltage level on noise channel. Noise channel allows VCM to reject any false knock signal by indicating amount of normal engine mechanical noise present. Normal engine noise varies depending on engine speed and load. DTC will set when VCM determines that an abnormally high noise channel voltage level is being experienced. Conditions for setting DTC

Knock Sensor Update Test

Timing retard is less than zero degrees.
System voltage 10-17.1 volts.
ECT greater than 140°F (60°C).
Engine run time is greater than 2 minutes.
Engine speed is 500-900 RPM on 4.3L, 5.0L and 5.7L.
Engine speed is 525-750 RPM on 7.4L.

Active Noise Channel Test

No ETC or TP DTCs set.
Knock sensor update test is complete.
ECT at least 140°F (60°C).
Engine speed 2000-3000 RPM.
Throttle angle is greater than 5.9 percent.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Install scan tool. Operate vehicle within the conditions for setting this DTC. Using scan tool, monitor SPECIFIC DTC for DTC P0327. If scan tool indicates DTC P0327 FAILED THIS IGN, go to step 4 . If scan tool does not indicate DTC P0327 FAILED THIS IGN, go to next step.
Turn ignition on, with engine off. Using scan tool, review and record FAILURE RECORDS data. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, monitor SPECIFIC DTC for DTC P0327. If scan tool indicates DTC P0327 FAILED THIS IGN, go to next step. If scan tool does not indicate DTC P0327 FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect knock sensor connector. Turn ignition on, with engine off. Using DVOM, check voltage between KS signal circuit of knock sensor connector and ground. If voltage reading is about 5 volts, go to next step. If voltage reading is not about 5 volts, go to step 8 .
Using DVOM, check resistance between knock sensor terminal and engine ground. If resistance is 100,000 ohms, go to next step. If resistance is not 100,000 ohms, go to step 12 .
Using DVOM, check voltage between knock sensor terminal and engine ground. Tap on engine lift bracket while observing DVOM. If a signal is indicated while tapping bracket, go to next step. If a signal is not indicated while tapping bracket, go to step 9 .
Check KS signal circuit for a poor connection at knock sensor. Repair as necessary. After repairs, go to step 14 . If no problem is found, go to step 10 .
Turn ignition off. Disconnect VCM harness connector. Turn ignition on. Check for open, short to voltage or short to ground in KS signal circuit between VCM and knock sensor. Repair as necessary. After repairs, go to step 14 . If no problem is found, go to step 10 .
Replace knock sensor. After replacing sensor, go to step 14 .
Turn ignition off. Disconnect VCM harness connector. Check KS signal circuit for a poor connection at VCM. If a problem is found, go to step 14 . If no problem is found, go to next step.
Check if KS module is fully seated or incorrectly installed. Repair as necessary. After repairs, go to step 14 . If no problem is found, go to next step.
Replace KS module. Operate vehicle within the conditions for setting this DTC. Using scan tool, monitor SPECIFIC DTC for this DTC. If scan tool indicates that this DTC FAILED THIS IGN, go to next step. If scan tool does not indicate that this DTC FAILED THIS IGN, go to step 14 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) is used to detect engine detonation (knock). If excessive knock is present, VCM will retard timing until knock goes away. When KS module in VCM determines that an abnormally high knock level exist, VCM will set DTC P0327. Conditions for setting DTC are

Timing is retarded no more than zero degrees.
System voltage between 10-17.1 volts.
ECT greater than 140°F (60°C).
Engine running at least 2 minutes.
Engine speed is 500-900 RPM.
Knock sensor noise less than 3 counts.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Operate vehicle within conditions required to set DTC. Using scan tool, select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to step 4 . If scan tool does not display DTC P0327 FAILED THIS IGN, go to next step.
Turn engine off. Turn ignition on, with engine off. Retrieve and record FAILED RECORDS data for DTC P0327. Operate vehicle within conditions required to set DTC. Select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0327 FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect knock sensor harness connector. Using a DVOM, check voltage between KS signal circuit and ground. Voltage reading should be about 5 volts. If voltage reading is not as specified, go to step 8 . If voltage reading is as specified, go to next step.
Using DVOM, check resistance between knock sensor terminal and engine ground. Resistance should be about 100,000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, go to step 12 .
Turn ignition off. Connect DVOM between knock sensor terminal and engine ground. Tap on engine while observing DVOM. If any signal is present, go to next step. If signal is not present, go to step 9 .
Check KS harness connector signal circuit for faulty terminal connection at KS. Repair as necessary. After repairs, go to step 14 . If terminal connections are okay, go to step 10 .
Turn ignition off. Disconnect VCM harness connector. Turn ignition on and check KS signal circuit between VCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 14 . If circuit is okay, go to step 10 .
Replace knock sensor. After replacing sensor, go to step 14 .
Turn ignition off. Disconnect VCM harness connector. Check KS signal circuit for proper terminal connection at VCM. Repair or replace terminal as necessary. After repairs, go to step 14 . If terminal is okay, go to next step.
Ensure KS module is fully seated and installed properly. If a problem is found, repair as necessary. After repairs, go to step 14 . If no problem is found, go to next step.
Replace KS module. Operate vehicle within conditions required to set DTC. Select DTC, SPECIFIC function and enter DTC P0327. If scan tool displays DTC P0327 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0327 FAILED THIS IGN, go to step 14 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P0327. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Check for faulty connection at VCM. Check KS and VCM connectors for damage. Ensure KS harness is not routed too close to high-voltage wires, such as spark plug cables, ignition coils or other high-voltage components. Insure KS is installed properly and ensure torque is to specification. Torque specification is 14 ft. lbs. (19 N.m).

DTC P0327: KNOCK SENSOR CIRCUIT-FRONT (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Knock Sensor (KS) system is used to detect engine detonation. PCM will retard spark timing based on signals from KS module. KS produces an AC signal voltage that is sent to KS module. The amount of AC voltage produced is proportional to amount of knock. When engine is operating, PCM will learn minimum and maximum frequency of noise engine produces. When PCM determines that this frequency is less than or greater than expected amount, DTC will set.

DTC will run when engine is operating for greater than 20 seconds, engine coolant temperature greater than 140°F (60°C), engine speed 1500-3500 RPM, throttle angle greater than 0.5 percent and MAP is less than 44 kPa. DTC determines that this frequency is less than or greater than expected amount for less than 3 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Ensure engine mechanical problem is not causing knock. Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function then enter DTC P0327. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect KS connector. Using DVOM, check resistance between KS and engine block. Resistance should be 93,000-107,000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, go to step 6 .
Turn ignition off. Connect DVOM between KS and ground. Set DVOM on AC voltage scale. Tap on engine while observing signal on DVOM. If any signal is present, go to next step. If signal is not present, go to step 7 .
Disconnect PCM harness connector. Turn ignition on, with engine off. Check KS signal circuit between PCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to step 8 .
Remove intake manifold. Check KS signal circuit between KS jumper harness connector (located at back of intake manifold) and KS connector for open or short to ground. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to next step.
Replace KS. After replacing sensor, go to step 10 .
Check KS signal circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 10 . If terminal connections are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO and REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check KS for proper connection. A loose or over-torqued KS can cause DTC to set.

DTC P0327: KNOCK SENSOR CIRCUIT-FRONT (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

When engine is operating, PCM will learn minimum and maximum frequency of noise engine produces. When PCM determines that this frequency is less than or more than expected amount, DTC will set. DTC will set when the following conditions are present

Engine operating for greater than 20 seconds.
Engine coolant temperature greater than 158°F (70°C).
Engine speed 1500-3500 RPM.
Throttle angle greater than 0.5 percent.
MAP is less than 60 kPa.
PCM determines frequency is less than or greater than expected amount for less than 3 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Ensure engine mechanical problem is not causing knock. Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function then enter DTC P0327. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
KS is located behind intake manifold. Disconnect KS connector. Using DVOM, check resistance between KS and engine block. Resistance should be 93,000-107,000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, go to step 6 .
Turn ignition off. Connect DVOM between KS and ground. Set DVOM on AC voltage scale. Tap on engine while observing signal on DVOM. If any signal is present, go to next step. If signal is not present, go to step 7 .
Disconnect PCM harness connector. Turn ignition on, with engine off. Check KS signal circuit between PCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to step 8 .
Remove intake manifold. Check KS signal circuit between KS jumper harness connector (located at back of intake manifold) and KS connector for open or short to ground. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to next step.
Replace KS. After replacing sensor, go to step 10 .
Check KS signal circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 10 . If terminal connections are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0327. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check KS for proper connection. A loose or over-torqued KS can cause DTC to set.

DTC P0330: KNOCK SENSOR CIRCUIT-BANK 2 (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine Speed (RPM)	Reference Signal (mV)
0	1.83
800	2.44
1600	3.66
2000	4.27
2400	5.49
2800	6.71
3200	8.54
3600	10.38
4000	12.82
4400	15.26
4800	18.31
5200	22.58
5600	28.69
5920	39.06
6200	39.06
6400	39.06

KNOCK SENSOR SPECIFICATIONS

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition on, with engine off. Review FREEZE FRAME data for this DTC and note parameters. Clear DTCs. Turn ignition off for 15 seconds. Start engine and operate at greater than 2000 RPM and as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0330 is set, go to next step. If DTC P0330 is not set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect knock sensor connector. Disconnect ECM harness connector located in engine compartment relay center. Check for poor connections and terminal tension at ECM and knock sensor connectors. Repair as necessary. After repairs, go to step 14 . If connections and terminals are okay, go to next step.
Turn ignition on, with engine off. Using DVOM, check voltage between ground and KS signal circuit at ECM harness connector. If any voltage is present, go to step 9 . If no voltage is present, go to next step.
Using DVOM, check harness continuity of KS signal circuit. If continuity exists, go to next step. If continuity does not exist, go to step 11 .
Using DVOM, check harness continuity between ground and KS sensor signal circuit. If continuity exists, go to step 10 . If continuity does not exist, go to next step.
Turn ignition off. Reconnect ECM connector. Turn ignition on, with engine off. Using test light connected to battery voltage, probe KS harness connector ground circuit. If test light is on, go to next step. If test light is off, go to step 12 .
Using test light connected to battery voltage, probe KS sensor shielding on wiring harness. If test light is on, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If test light is off, go to step 13 .
Repair short to voltage is signal circuit. After repairs, go to step 14 .
Repair short to ground in signal circuit. After repairs, go to step 14 .
Repair open or high resistance in signal circuit. After repairs, go to step 14 .
Repair open or high resistance in ground circuit. After repairs, go to step 14 .
Repair knock sensor shield circuit. After repairs, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate at greater than 2000 RPM and as close to conditions recorded in FREEZE FRAME as possible. Check for DTCs. If DTC P0330 is set, go to step 2 . If DTC P0330 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

Check for poor connections at ECM or at component. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connection.

Check for misrouted wiring harness. Inspect harness to ensure that it is not routed too close to high voltage wires (spark plug wires) or too close to high current devices (alternator, motors, solenoids).

Check knock sensor for proper installation. A knock sensor that is loose or over tightened may cause this DTC to set.

DTC P0332: KNOCK SENSOR CIRCUIT-BANK 2 (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

No active CKP, ECT, MAF, TP or VSS sensor DTCs set.
ECT greater than 167°F (75°C).
Engine load is greater than 3 percent.
TP angle greater than 3 percent.
Engine speed is 1000-4000 RPM.
Maximum system spark retard less than 15 percent.
System voltage greater than 9 volts.
PCM detect a KS 2 signal voltage within the calculated average voltage range.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine knock can be heard, repair mechanical problem before proceeding with test. After repairs, operate vehicle within conditions required to set DTC. Using scan tool, select DTC, SPECIFIC function and enter this DTC. If scan tool displays DTC FAILED THIS IGN, go to step 4 . If scan tool does not display DTC FAILED THIS IGN, go to next step.
Turn ignition on, engine off. Read and record FAILURE RECORDS data for DTC P0327. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays that this DTC FAILED THIS IGN, go to next step. If scan tool does not display that this DTC FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect KS No. 2 connector. Using a DVOM, check voltage between engine ground and terminal at KS. If voltage reading is 5 volts, go to next step. If voltage reading is not 5 volts, go to step 8 .
Connect DVOM to bank 2 KS terminal and ground. Select 2-volt AC scale on DVOM. Start and operate engine at idle. Observe DVOM. If voltage is indicated on DVOM, go to step 9 . If voltage is not indicated, go to next step.
Turn ignition off. With DVOM still connected between KS terminal and engine ground, tap on engine while observing DVOM. If any signal is present, go to next step. If signal is not present, go to step 9 .
Check KS harness connector for incorrect routing or faulty terminal connection at KS. Repair as necessary. After repairs, go to step 12 . If no problem is found, go to step 10 .
Turn ignition off. Disconnect PCM harness connectors. Turn ignition on and check KS signal circuit between PCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 12 . If no problem is found, go to step 10 .
Replace KS. After replacing sensor, go to step 12 .
Turn ignition off. Disconnect PCM harness connectors. Check KS signal circuit for proper terminal connection at PCM. Repair or replace terminal as necessary. After repairs, go to step 12 . If terminal is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Read and record FAILURE RECORDS data for DTC P0327. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0327 FAILED THIS IGN, return to step 2 . If scan tool does not display DTC P0327 FAILED THIS IGN, repair is complete.

DTC P0332: KNOCK SENSOR CIRCUIT-REAR (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Ensure engine mechanical problem is not causing knock. Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function then enter this DTC. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect KS connector. Using DVOM, check resistance between KS and engine block. Resistance should be 93,000-107,000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, go to step 6 .
Turn ignition off. Connect DVOM between KS and ground. Set DVOM on AC voltage scale. Tap on engine while observing signal on DVOM. If any signal is present, go to next step. If signal is not present, go to step 7 .
Disconnect PCM harness connector. Turn ignition on, with engine off. Check KS signal circuit between PCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to step 8 .
Remove intake manifold. Check KS signal circuit between KS jumper harness connector (located at back of intake manifold) and KS connector for open or short to ground. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to next step.
Replace KS. After replacing sensor, go to step 10 .
Check KS signal circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 10 . If terminal connections are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO and REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check KS for proper connection. A loose or over-torqued KS can cause DTC to set.

DTC P0332: KNOCK SENSOR CIRCUIT (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine operating for greater than 20 seconds.
Engine coolant temperature greater than 158°F (70°C).
Engine speed 1500-3500 RPM.
Throttle angle greater than 0.5 percent.
MAP is less than 60 kPa.
PCM determines frequency is less than or greater than expected amount for less than 3 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Ensure engine mechanical problem is not causing knock. Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter DTC P0332. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect KS harness connector. Using DVOM, check resistance between KS signal circuit and ground. If resistance is 93,000-107,000 ohms, go to next step. If resistance is not 93,000-107,000 ohms, go to step 6 .
Turn ignition off. Connect DVOM between KS and ground. Set DVOM to AC voltage scale. Tap on engine while observing signal on DVOM. If any signal is present, go to next step. If signal is not present, go to step 7 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition on and check KS signal circuit between PCM and KS harness connector for open, short to voltage or short to ground. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to step 8 .
Remove intake manifold. Check for open or short to ground in signal circuit between KS jumper harness connector located at back of intake manifold. Repair as necessary. After repairs, go to step 10 . If circuit is okay, go to next step.
Replace KS. After replacing sensor, go to step 10 .
Check KS signal circuit for poor terminal connection at PCM. Repair as necessary. After repairs, go to step 10 . If terminal connection is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0332. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check KS for proper connection. A loose or over-torqued KS can cause DTC to set.

DTC P0335: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT (2.2L "J" BODY & "S" SERIES & 2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) supplies battery power and ground to CKP sensor. CKP sensor sends a reference signal to PCM 7 times per revolution to indicate crankshaft position and engine speed. The seventh pulse is the sync pulse and is used for crankshaft position reference. PCM calculates when to pulse ignition coils based on these signals. Condition for setting this DTC is as follows

7X resync counter is greater than 15 counts within 4 minutes and 15 seconds.
DTC P0341 not set.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine will not start, go to NO START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article. If engine will start, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle for 5 minutes or until Malfunction Indicator Light (MIL) turns on. If MIL is on, go to next step. If MIL is off, go to step 5 .
With engine running, wiggle PCM connectors, CKP sensor connector and related wiring. If engine stumbles, go to step 6 . If engine does not stumble, go to step 7 .
Operate any non-engine related accessories on vehicle. If MED. RESOLUTION RESYNC CNTR on scan tool resyncs while operating accessories, go to step 9 . If MED. RESOLUTION RESYNC CNTR on scan tool does not resync while operating accessories, go to step 4 .
Repair poor connector connection, wiring or connector that caused engine to stumble. After repairs, go to step 13 .
If MIL turned on in step 3 , go to next step. If MIL did not turn on, go to step 13 .
Check wiring to PCM, ICM and CKP sensor for pinched or worn through wire insulation. Repair as necessary. After repairs, go to step 13 . If wiring is okay, go to step 10 .
Repair faulty circuit or accessory component that caused MED. RESOLUTION RESYNC CNTR on scan tool to resync. After repairs, go to step 13 .
Replace CKP sensor. Start engine and allow engine to idle for 5 minutes or until MIL turns on. If MIL turns on, go to next step. If MIL does not turn on, go to step 13 .
Replace PCM. Program replacement PCM using required equipment. Start engine and allow it to idle for 5 minutes or until MIL turns on. If MIL is on, go to next step. If MIL is off, go to step 13 .
Replace ICM. Start engine and allow it to idle for 5 minutes or until MIL turns on. If MIL is on, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If MIL is off, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0335. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 3 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

If complaint is engine cranks but will not run, DTC P0335 may be set if engine is cranked more than 15 times without turning ignition off between starting attempts.

An intermittent can be caused by a defective CKP sensor reluctor wheel. Remove CKP sensor. Inspect reluctor wheel through CKP sensor mounting hole. Check porosity and condition of reluctor wheel. Intermittent can also be caused by a rubbed-through wire insulation or a poor connection.

DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor works in conjunction with a 58-tooth reluctor wheel on crankshaft. ECM pulls CKP sensor signal circuit low and monitors voltage on circuit. As each reluctor wheel tooth rotates past sensor, sensor's internal circuitry causes voltage to be applied to signal circuit, creating a square wave signal used by ECM. Reluctor wheel teeth are 6 degrees apart. Having only 58 teeth leaves a 12-degree span that is uncut. This creates a signature pattern that enables ECM to determine crankshaft position.

ECM can determine which 2 cylinders are approaching top dead center based on CKP signal alone. Camshaft Position (CMP) sensor signal is then used to determine which 2 cylinders are on firing stroke. ECM can then properly synchronize ignition system, fuel injectors and knock control. This sensor is also used to detect misfire. Refer to DTC P0300 for misfire detection. For duplication of DTC, ECM must not detect CKP sensor pulses.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Attempt to start engine. If engine starts and runs, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If engine does not start, go to next step.
Turn ignition off. Disconnect CKP sensor connector. Turn ignition on, with engine off. Using DVOM, measure voltage between ground and CKP sensor harness connector signal circuit (ECM side). If voltage reading is 0.5-1.5 volts, go to step 6 . If voltage reading is not 0.5-1.5 volts, go to next step.
Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. Using DVOM, check harness continuity of CKP sensor signal circuit. If continuity exists, go to next step. If continuity does not exist, go to step 10 .
Using DVOM, check harness continuity between ground and CKP sensor signal circuit. If continuity exists, go to step 9 . If continuity does not exist, go to step 14 .
Using test light connected to battery voltage, probe CKP sensor harness connector ground circuit (ECM side). If test light is on, go to step 8 . If test light is off, go to next step.
Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. Using DVOM, check harness continuity of CKP sensor ground circuit. If continuity exists, go to step 14 . If continuity does not exist, go to step 11 .
Disconnect main fuel injector connector. Connect Signal Generator Tester (J-33431-B) to CKP sensor harness connector (ECM side). Using scan tool, monitor engine RPM. If RPM is indicated on scan tool, go to step 12 . If RPM is not indicated on scan tool, go to step 15 .
Repair short to ground in signal circuit. After repairs, go to step 16 .
Repair open or high resistance in signal circuit. After repairs, go to step 16 .
Repair open or high resistance in ground circuit. After repairs, go to step 16 .
Check for poor connection and terminal tension at CKP sensor connector. Check sensor for proper installation. A sensor that is loose or not fully seated could cause an excessive air gap between sensor and reluctor wheel. Repair as necessary. After repairs, go to step 16 . If connections and terminals are okay, go to next step.
Replace CKP sensor. After replacing sensor, go to step 16 .
Check for poor connections and terminal tension at ECM connectors. Repair as necessary. After repairs, go to step 16 . If connections and terminals are okay, go to next step.
Replace ECM. New ECM must be programmed with theft deterrent module frequency code currently on vehicle. After replacing ECM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0335 is set, go to step 2 . If DTC P0335 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

Check CKP sensor for proper installation. A sensor that is loose or not fully seated, causing an excessive air gap between sensor and reluctor wheel, may cause this DTC to set.

DTC P0335: CRANKSHAFT POSITION SENSOR "A" CIRCUIT (3.5L "W" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor in this engine are actually 2 sensors within a single housing. Each sensor has a separate power, ground (reference low) and a signal circuit. PCM supplies battery voltage, ground (return circuit) to both sensors. The power and reference low circuits are also connected to the Camshaft Position (CMP) sensor. Two separate signal circuits connect the CKP sensor to the PCM.

The PCM uses 3 different modes of decoding crankshaft position. During normal operation, PCM performs an angle based calculation using both signals to determine crankshaft position. The dual sensor allows engine to run even if one signal is lost. If either signal is lost, PCM switches to a time based method of calculating crankshaft position. In Time "A" mode, PCM is using only the signal from sensor "A". In Time "B" mode, PCM is using only the signal from sensor "B". If the lost signal is restored, PCM will continue to operate in Time "A" or "B" mode for the remainder of the current ignition cycle.

PCM will automatically revert back to angle mode on the next start-up if fault is not present. Scan tool can display the crank position sensing decode mode. DTC will set when PCM detects a problem with CKP sensor "A" signal.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Using scan tool, check if DTC P0340 is also set. If DTC P0340 is set, diagnose DTC P0340. If DTC P0340 is not set, go to next step.
Start and operate engine. If engine starts, go to next step. If engine does not start, go to step 6 .
Using scan tool, select CKP SENSOR STATUS. Start engine. If scan tool indicates CKP sensor status angle, go to next step. If scan tool does not indicate CKP sensor status angle, go to step 6 .
Wiggle related harnesses and connectors while monitoring scan tool display. If scan tool indicates that CKP sensor status changes from Time "A" or Time "B", or engine stalls, go to step 13 . If scan tool does not indicate that CKP sensor status changed or engine did not stall, problem is intermittent.
This step applies to the senor and related circuit that is malfunctioning. For example, if scan tool indicates Time "A", the system is using the signal from CKP sensor "A". Diagnose CKP sensor "B" and related circuits. To diagnose, turn ignition off. Disconnect affected CKP sensor harness connector. Using DVOM, check voltage on power circuit at CKP sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 14 .
Check voltage between power circuit and ignition circuit at CKP sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 15 .
Turn ignition off and wait 15 seconds. Turn ignition on. Using scan tool, clear DTCs. Using scan tool, command system to operate in appropriate Time mode for sensor being tested. Monitor 24X crank sensor data. Using a test light connected to battery voltage, momentarily touch signal circuit several times. If RPM is indicated on scan tool, go to step 20 . If RPM is not indicated, go to next step.
Turn ignition off. Disconnect PCM harness connector C1. Turn ignition on. Check voltage on CKP sensor signal circuit on PCM harness connector. If voltage is indicated, go to step 18 . If voltage is not indicated, go to next step.
Using DVOM, check signal circuit resistance between CKP harness connector and PCM harness connector. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 16 .
Check resistance between ground and signal circuit. If resistance is infinite, go to next step. If resistance is not infinite, go to step 17 .
Check resistance between CKP sensor "A" and "B" signal circuits. If resistance is infinite, go to step 22 . If resistance is not infinite, go to step 19 .
Repair harness or connections as necessary. After repairs, go to step 24 .
Repair open/high resistance power circuit between sensor and splice. After repairs, go to step 24 .
Repair open/high resistance ground circuit between sensor and splice. After repairs, go to step 24 .
Repair open/high resistance in sensor signal circuit. After repairs, go to step 24 .
Repair sensor signal circuit shorted to ground. After repairs, go to step 24 .
Repair sensor signal circuit shorted to power. After repairs, go to step 24 .
Repair signal circuits shorted together. After repairs, go to step 24 .
Check for poor connections/terminal tension at CKP sensor. Repair as necessary. After repairs, go to step 24 . If connections are okay, go to next step.
Replace CKP sensor. After replacing sensor, go to step 24 .
Check for poor connections/terminal tension at PCM harness connector. Repair as necessary. After repairs, go to step 24 . If connections are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, clear DTCs. Turn ignition off. Wait 15 seconds, then operate vehicle within conditions required to set this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, go to step 2 .
Using scan tool, select CAPTURE INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

For any test that requires probing PCM or component harness connectors, use Connector Test Adapter Kit (J-35616-A). This will prevent damage to harness connector terminals. Check for poor connections at PCM or at component. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connection.

Check CKP sensor for proper installation. A sensor that is loose or not fully seated, causing an excessive air gap between sensor and reluctor wheel, may cause this DTC to set.

DTC P0335: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor is mounted on right rear of engine block, near starter. CKP reluctor (24X) is located on rear of crankshaft. CKP sensor will send a pulse on every falling edge of 24X reluctor wheel. A misfire will cause a change in crankshaft speed. PCM times interval between each pulse and compares each new interval with previous one to determine when an excessive change in crankshaft speed has occurred. A certain amount of acceleration/deceleration is expected between each firing stroke, but if crankshaft speed changes are more than expected amount, PCM will interpret this as a misfire. PCM continuously calculates crankshaft position from low and high resolution signals. This information is used to determine which cylinder is misfiring so that PCM can increment appropriate misfire counter.

Conditions for running this DTC are: DTCs P0101, P0102, P0103, P0341, P0342 or P0343 not set, CMP sensor is transitioning, MAF greater than 3 gm/s and ignition switch is in CRANK mode. DTC will set when PCM determines that there is no CKP sensor signal for 3 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine starts and runs, go to next step. If engine does not start and run, go to step 4 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function then enter this DTC. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . CAUTION: Before proceeding, remove ignition and fuel feed circuit fuses to prevent personal injury from engine rotation, sparks or excessive engine fueling.
Disconnect CKP sensor harness connector. Turn ignition on, with engine off. Connect a test light between ground and CKP sensor ignition feed circuit PCM side of CKP sensor harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 8 .
Connect test light between CKP sensor harness connector ignition feed and ground circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 9 .
Momentarily connect test light between CKP sensor signal circuit and CKP sensor ignition feed circuit. If fuel pump operates when ignition voltage was applied to CKP sensor signal circuit, go to step 11 . If fuel pump does not operate, go to next step.
Reconnect CKP sensor connector. Turn ignition off. Disconnect PCM harness connector. Using Brown jumper from Connector Kit (J-35616-A) and DVOM set to 40 VAC scale, check voltage (front probe) to signal circuit. If voltage reading is 4-6 volts, go to step 15 . If voltage reading is not as specified, go to step 10 .
Check for open or short in CKP sensor ignition feed circuit. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to step 15 .
Check for open or short in CKP sensor ground circuit. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to step 15 .
Check for CKP sensor signal circuit for open, short to ground or short to voltage. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to next step.
Visually inspect CKP sensor for physical damage, loose or improper installation, wiring routed too close to secondary ignition components or poor connections/terminal contact at sensor or PCM. Repair as necessary. After repairs, go to step 16 . If components and circuits are okay, go to next step.
Visually inspect CKP sensor reluctor wheel for damage. Replace or repair reluctor wheel as necessary. After repairs, go to step 16 . If reluctor wheel is okay, go to next step.
Check for poor connections/terminal at CKP sensor or for proper reluctor wheel installation. Repair as necessary. After repairs, go to step 16 .
Replace CKP sensor. After replacing sensor, go to step 16 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for poor connections/terminal tension at CKP sensor. Check for excessive timing gear/chain tension, excessive distributor drive backlash, damaged crankshaft reluctor wheel or for improper installation. Check engine front cover assembly for damage or sensor coming in contact with reluctor wheel.

DTC P0335: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor is mounted on right rear of engine block, behind starter. CKP reluctor (24X) is located on rear of crankshaft. CKP sensor will send a pulse on every falling edge of 24X reluctor wheel. A misfire will cause a change in crankshaft speed. PCM times interval between each pulse and compares each new interval with previous one to determine when an excessive change in crankshaft speed has occurred. A certain amount of acceleration/deceleration is expected between each firing stroke, but if crankshaft speed changes are more than expected amount, PCM will interpret this as a misfire. PCM continuously calculates crankshaft position from low and high resolution signals. This information is used to determine which cylinder is misfiring so that PCM can increment appropriate misfire counter. Conditions for setting DTC

DTCs P0101, P0102, P0103, P0341, P0342 or P0343 not set.
CMP sensor is transitioning.
Ignition voltage 5-17 volts.
MAF greater than 3 gm/s.
Ignition switch in CRANK mode.
PCM determines CKP sensor signal out of range for less than 3 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine starts and runs, go to next step. If engine does not start and run, go to step 4 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function then enter DTC P0335. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . CAUTION: Before proceeding, remove ignition and fuel feed circuit fuses to prevent personal injury from engine rotation, sparks or excessive engine fueling.
Disconnect CKP sensor harness connector. Turn ignition on, with engine off. Connect a test light between ground and PCM connector (PCM side), CKP sensor ignition feed circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 8 .
Connect test light between CKP sensor harness connector ignition feed and ground circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 9 .
Momentarily connect test light between CKP sensor signal circuit and CKP sensor ignition feed circuit. If fuel pump operates when ignition voltage was applied to CKP sensor signal circuit, go to step 11 . If fuel pump does not operate, go to next step.
Connect CKP sensor connector. Turn ignition off. Disconnect PCM harness connector. Using Brown jumper from Connector Kit (J-35616-A) and DVOM set to 40 VAC scale, check voltage (front probe) to signal circuit. If voltage reading is 4-6 volts, go to step 15 . If voltage reading is not as specified, go to step 10 .
Check for open or short in CKP sensor ignition feed circuit. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to step 15 .
Check for open or short in CKP sensor ground circuit. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to step 15 .
Check for CKP sensor signal circuit for open, short to ground or short to voltage. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to next step.
Visually inspect CKP sensor for physical damage, loose or improper installation, wiring routed too close to secondary ignition components or poor connections/terminal contact at sensor or PCM. Repair as necessary. After repairs, go to step 16 . If components and circuits are okay, go to next step.
Visually inspect CKP sensor reluctor wheel for damage. Replace or repair reluctor wheel as necessary. After repairs, go to step 16 . If reluctor wheel is okay, go to next step.
Check for poor connections/terminal at CKP sensor or for proper reluctor wheel installation. Repair as necessary. After repairs, go to step 16 .
Replace CKP sensor. After replacing sensor, go to step 16 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0335. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0336: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT-SIGNAL INTERMITTENT OR NOISY-EXTRA PULSES (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

CKP sensor defines engine position by generating an electrical pulse each time it passes by a notch of the crankshaft reluctor wheel. PCM uses crankshaft sensor pulses for fuel delivery and spark timing.

DTC will set if extra or missing crankshaft sensor pulses are detected or time between reference pulses is too long or too short when RPM is greater than 3600 RPM or under 2600 RPM, engine run time is greater than 10 seconds, coolant temperature is greater than 149°F (65°C), TP is greater than 9.8 percent open, no ECT, TP sensor or P0125 DTC have been set. CKP sensor is continuously checked after these conditions have been met.

Start engine. Check if DTC P0336 is active. If DTC P0336 is not active, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If DTC P0336 is active, go to next step.
Monitor scan tool RPM on initial start up. If RPM increases by several thousand, then return to normal, go to next step. If RPM does not increase, check connections to CKP sensor and PCM ground.
Check for Electromagnetic Interference (EMI) cause by ignition cables routed too close to CKP sensor. Check for faulty generator.

When attempting to diagnose an intermittent problem, use scan tool to review malfunction history information. This data can be used to duplicate a problem. Ensure secondary wires are not in close proximity of CKP sensor signal wires, offsetting a crank signal to PCM.

DTC P0336: 24X REFERENCE SIGNAL CIRCUIT (3.1L "N" & "W" BODIES) OR CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT PERFORMANCE (3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Ignition Control Module (ICM) produces 24X reference signal. ICM calculates 24X reference signal by filtering Crankshaft Position (CKP) sensor 24X pulses when engine is running and CKP pulses are also being received. PCM uses this information to calculate engine speed and CKP at engine speeds less than 1200 RPM. PCM compares number of 24X reference pulses to 3X reference pulses and Camshaft Position (CMP) pulses. If PCM receives incorrect number of pulses, DTC P0336 will set. For duplication of DTC, ensure

Engine running and PCM receiving 3X reference pulses.
Ratio of 24X reference pulses to 3X reference pulses received by PCM is incorrect.
Conditions present for 30 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Attempt to start engine. If engine starts and runs, go to next step. If engine does not start and run, see NO START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTC P0336. Start engine and allow it to idle for one minute. Read DTCs. If DTC P0336 resets, go to next step. If DTC does not reset, go to «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect CMP sensor connector. Using a DVOM, check voltage at Camshaft Position (CMP) sensor and Crankshaft Position (CKP) sensor feed circuit. If DVOM reads battery voltage, go to next step. If DVOM does not read close to battery voltage, go to step 6 .
Turn ignition off. Disconnect PCM harness connector. Turn ignition, with engine off. Using a fused jumper wire connected to battery voltage, connect jumper wire to sensor feed circuit. Check for voltage at reference signal circuit. If DVOM reads battery voltage, go to step 12 . If DVOM does not read close to battery voltage, go to step 7 .
Check for open or short to ground in sensor feed circuit. Check connection at PCM connector. Check connections at 24X CKP and CMP sensors. Repair as necessary. After repairs are complete, go to next step. If circuits are okay, go to step 8 .
Check connections at PCM and replace terminals as necessary. After repairs, go to step 15 . If terminals are okay, go to next step.
Check reference signal circuit connections at CKP sensor. Replace terminals as necessary. After repairs, go to step 15 . If terminals are okay, go to next step.
Check reference signal circuit for open or short to ground. Repair as necessary. After repairs, go to step 15 . If circuit is okay, go to next step.
Disconnect 24X reference circuit to CKP and CMP sensors. Using DVOM, check continuity between CMP sensor harness reference low to CKP harness reference low circuit. Check continuity between CKP harness reference low circuit and PCM. If DVOM reads continuity (zero ohms) on both tests, go to step 12 . If continuity does not exists, go to next step.
Check for open in circuits, or faulty connections at PCM or sensors. Repair as necessary. After repairs, go to step 15 .
Turn ignition off. Disconnect 24X CKP sensor connector. Turn ignition on. Using a test light connected to battery voltage, probe reference low circuit at harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 14 .
Replace 24X CKP sensor. After replacing sensor, go to next step.
Check connections to PCM. If connections are okay, replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Read and record FAILURE RECORDS data for DTC P0336. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0336 FAILED THIS IGN, return to step 2 . If scan tool does not display DTC P0336 FAILED THIS IGN, repair is complete.

Check for incorrect harness routing near secondary ignition components, ignition coil arcing to wiring harness or ICM. Check ignition coils for cracks, carbon tracking or other signs of damage. Check for secondary ignition wire(s) arcing to wiring harness.

Check for faulty connections or damaged harness. Observe a voltmeter connected to 24X CKP sensor reference circuit at PCM harness connector while moving all related harness and connectors. A change in voltage indicates fault location.

DTC P0336: 18X REFERENCE SIGNAL CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Ignition Control Module (ICM) produces 18X reference signal. ICM calculates 18X reference signal by filtering Crankshaft Position (CKP) sensor 18X pulses when engine is running and CKP pulses are also being received. PCM uses this information to calculate engine speed and CKP at engine speeds less than 1200 RPM. PCM compares number of 18X reference pulses to 3X reference pulses and Camshaft Position (CMP) pulses. If PCM receives incorrect number of pulses, DTC P0336 will set. For duplication of DTC, ensure

Engine running and PCM receiving 3X reference pulses.
Ratio of 18X reference pulses to 3X reference pulses received by PCM does not equal 6.
Ratio of 3X reference pulses to CMP pulses received by PCM equals 6.
Conditions present for 600 engine revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Attempt to start engine. If engine starts and runs, go to next step. If engine does not start and run, see NO START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Using scan tool, clear DTC P0336. Start and allow engine to idle for one minute. Read DTCs. If DTC P0336 resets, go to next step. If DTC does not reset, go to «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Disconnect ICM and PCM harness connectors. Check for open or short to ground in 18X reference circuit between ICM and PCM harness connectors. Repair as necessary. After repairs, go to step 11 . If no problem is found, go to next step.
Reconnect ICM connector. Using DVOM, check voltage on 18X reference circuit at PCM harness connector while cranking engine. If voltage reading is about 3 volts, go to step 8 . If voltage reading is not as specified, go to next step.
Check for faulty connections at ICM. Repair as necessary. After repairs, go to step 11 . If connections are okay, go to next step.
Replace ICM. After replacing module, go to step 11 .
Check for incorrect harness routing near secondary ignition components, ignition coil arcing to wiring harness or ICM. Check ignition coils for cracks, carbon tracking or other signs of damage. Check for secondary ignition wire(s) arcing to wiring harness. Repair as necessary. After repairs, go to step 11 . If no problem is found, go to next step.
Check for faulty connections at PCM. Repair as necessary. After repairs, go to step 11 . If connections are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Read and record FAILURE RECORDS data for DTC P0336. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0336 FAILED THIS IGN, return to step 2 . If scan tool does not display DTC P0336 FAILED THIS IGN, repair is complete.

Check for faulty connections or damaged harness. Observe a voltmeter connected to 18X reference circuit at PCM harness connector while moving all related harness and connectors. A change in voltage indicates fault location.

DTC P0336: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT PERFORMANCE (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor sends a reference signal to VCM, indicating crankshaft position and RPM. Information is used to determine when to pulse ignition coil, fuel injectors and control ignition timing. DTC will set when the following conditions are present

Engine cranking and VCM receives 4 or more camshaft position signals without crankshaft position signal.
Crankshaft position sensor signal is missing for at least 0.5 second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and run vehicle. If vehicle starts and continues to run, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If vehicle does not start and continue to run, go to next step.
Turn ignition off. Disconnect crankshaft position sensor connector. Turn ignition on, engine off. Using test light connected to ground, probe ignition feed circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 6 .
Connect test light between ignition feed circuit and ground circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
Turn ignition off. Install Gray jumper wires from Connector Test Kit (J-35616-A) between engine harness connector and crankshaft position sensor. Set DVOM to duty cycle position. Connect DVOM between signal circuit and ground circuit of crankshaft position sensor connector (engine harness side). Crank engine. If duty cycle is less than 40-60 percent (V6 engines) or less than 20-40 percent (V8 engines), go to step 8 . If duty cycle is not as specified, go to step 9 .
Repair open or short to ground in CKP sensor ignition feed circuit. After repairs, go to step 12 .
Check for open in CKP sensor low circuit. If CKP sensor low circuit is open, go to step 10 . If circuit is okay, go to step 11 .
Check for open in signal (3X) circuit or open in CKP sensor low circuit. If circuit is open, go to step 10 . If circuit is okay, go to step 11 .
Replace CKP sensor. Perform CKP SYSTEM VARIATION LEARN PROCEDURE. After performing CKP learn procedure, go to step 12 .
Repair as necessary. After repairs, go to step 12 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. If DTC is intermittent, see appropriate TROUBLE SHOOTING - NO CODES article.

DTC P0336: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT PERFORMANCE (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor sends reference signal to VCM to indicate position of crankshaft and engine speed (RPM). VCM uses this information to determine ignition coil, fuel injector and ignition timing. Conditions for setting DTC

Engine cranking and VCM receives 4 or more camshaft signals without receiving CKP signal.
CKP signal is missing for at least 0.5 second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If vehicle starts and runs, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If vehicle does not start and run, go to next step.
Disconnect CKP sensor harness connector. Using a test light, probe ignition feed circuit of CKP sensor connector (engine side) to ground. Turn ignition on, engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step 6 .
Connect test light between ignition feed circuit and sensor low circuit of CKP sensor connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
Turn ignition off. Install Gray jumpers from Connector Test Kit (J-35616-A) between engine harness connector and CKP sensor connector. Install DVOM set on duty cycle between CKP sensor 3X signal and low circuit terminals. Crank engine. If duty cycle is 40-60 percent, go to step 8 . If duty cycle is not 40-60 percent, go to step 9 .
Repair open or short to ground in CKP sensor ignition feed circuit. After repairs, go to step 12 .
Check for open in CKP sensor low circuit. If CKP sensor low circuit is open, go to step 10 . If circuit is okay, go to step 11 .
Check for open in CKP sensor 3X signal circuit or CKP sensor low circuit. If circuit is open, go to step 10 . If circuit is okay, go to step 11 .
Replace CKP sensor. Ensure CKP sensor mounting surface is clean and free of debris. After repairs, go to step 12 .
Repair as necessary. After repairs, go to step 12 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter this DTC. Operate vehicle within conditions required to set DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. Check if any undiagnosed DTCs are displayed. Diagnose affected DTCs. If no additional DTCs are displayed, system is okay.

Check for faulty connections or damaged harness. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location.

DTC P0336: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT PERFORMANCE (4.8L, 5.3L, 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC will set when PCM determines that CKP sensor signal is out of range for less than one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle for 2 minutes. Using scan tool, monitor FAILED THIS IGNITION display under this DTC. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Visually inspect CKP sensor circuits for routing too close to secondary ignition components, after-market components, solenoids, relays and motors. Repair as necessary. After repairs, go step 9 . If routing is okay, go to next step.
Check for poor connections/terminal tension at CKP sensor. Repair as necessary. After repairs, go to step 9 . If connection or terminal tension is okay, go to next step.
Check for poor CKP sensor circuit connections/terminal tension at PCM. Repair as necessary. After repairs, go to step 9 . If connection or terminal tension is okay, go to next step.
Remove and inspect CKP sensor. Replace CKP sensor if necessary. If CKP sensor is okay, go to next step.
Visually inspect CKP sensor reluctor wheel for damage. Replace or repair reluctor wheel as necessary. If reluctor wheel is okay, go to next step.
Replace CKP sensor. After replacing sensor, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for poor connections/terminal tension at CKP sensor. Check for damaged crankshaft reluctor wheel or for improper installation. Check engine front cover assembly for damage or sensor coming in contact with reluctor wheel.

DTC P0336: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT PERFORMANCE (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine speed 500-4000 RPM.
Ignition voltage 5-17 volts.
PCM determines CKP sensor signal out of range for less than one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle for 2 minutes. Using scan tool, monitor FAILED THIS IGNITION display under DTC P0336. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Visually inspect CKP sensor circuits for routing too close to secondary ignition components, after-market components, solenoids, relays and motors. Repair as necessary. After repairs, go step 9 . If routing is okay, go to next step.
Check for poor connections/terminal tension at CKP sensor. Repair as necessary. After repairs, go to step 9 . If connection or terminal tension is okay, go to next step.
Check for poor CKP sensor circuit connections/terminal tension at PCM. Repair as necessary. After repairs, go to step 9 . If connection or terminal tension is okay, go to next step.
Remove and inspect CKP sensor. Replace CKP sensor if necessary. If CKP sensor is okay, go to next step.
Visually inspect CKP sensor reluctor wheel for damage. Replace or repair reluctor wheel as necessary. If reluctor wheel is okay, go to next step.
Replace CKP sensor. After replacing sensor, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0336. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0337: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT-LOW FREQUENCY (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine speed is less than 4000 RPM.
MAF sensor is at least 5 gm/s.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Turn ignition off. Disconnect crankshaft position sensor connector. Turn ignition on, with engine off. Using a test light, probe signal circuit of crankshaft position sensor connector (engine harness side) to ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 8 .
Turn ignition off. Using test light connected to battery voltage, probe ground circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
Disconnect VCM harness connector. Using test light connected to battery voltage, probe ignition feed circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to step 10 . If test light does not illuminate, go to next step.
Reconnect VCM harness connector. Install Gray jumper wires from Connector Test Kit (J-35616-A) between engine harness connector and crankshaft position sensor. Set DVOM to duty cycle position. Connect DVOM between signal circuit and ground circuit of crankshaft position sensor harness connector. Crank engine. If displayed duty cycle is less than 40 percent (4.3L) or 30 percent (5.0L, 5.7L and 7.4L), go to step 11 . If duty cycle is not less than specified, go to next step.
Check for poor connection at crankshaft position sensor. If connection is faulty, go to step 12 .
Check for open in ground circuit. If circuit is open, go to step 12 . If a circuit is okay, go to step 9 .
Check for open or short to ground in ignition feed circuit. If circuit is open or shorted, go to step 12 .
Check for poor connection at VCM connector. If connection is faulty, go to step 12 . If connection is okay, go to step 13 .
Repair short to ground in signal circuit. After repairs, go to step 14 .
Replace crankshaft position sensor. After replacing sensor, go to step 14 .
Repair circuit as necessary. After repairs, go to step 14 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

An intermittent may be caused by a poor connection, rubbed through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. If DTC is intermittent, see appropriate TROUBLE SHOOTING - NO CODES article.

DTC P0337: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT-LOW FREQUENCY (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine speed less than 4000 RPM.
MAF at least 5 grams per second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Disconnect CKP sensor harness connector. Connect a test light between engine ground and signal circuit at CKP sensor. Turn ignition on, engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step 8 .
Turn ignition off. Connect test light between battery voltage and ground circuit at CKP sensor. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
Disconnect VCM harness connector. Connect test light between battery voltage and ignition feed circuit at CKP sensor. If test light illuminates, go to step 10 . If test light does not illuminate, go to next step.
Reconnect VCM harness connector. Install Gray jumpers from Connector Tester Kit (J-35616-A) between CKP sensor and CKP sensor harness connector. Start engine. Connect a DVOM (set to duty cycle) between CKP sensor signal and ground circuits. If duty cycle is less than 40 percent, go to step 11 . If duty cycle is not less than 40 percent, go to next step.
Check for faulty connection at CKP sensor. If a problem is found, go to step 12 .
Check for open in CKP sensor ground circuit. If circuit is open, go to step 12 . If circuit is okay, go to step 9 .
Check for open or short to ground in CKP sensor signal circuit. If circuit is open, go to step 12 .
Check for faulty connection at VCM. If faulty connection is found, go to step 12 . If connection is okay, go to step 13 .
Repair short to ground in CKP sensor signal circuit. After repairs, go to step 14 .
Replace CKP sensor. After replacing sensor, go to step 14 .
Repair circuit as necessary. After repairs, go to step 14 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter this DTC. Operate vehicle within conditions required to set DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Check for faulty connections or damaged harness. Observe scan tool while moving all related harnesses and connectors. A change in scan tool display indicates fault location.

DTC P0338: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT HIGH FREQUENCY (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Crankshaft Position (CKP) sensor sends a reference signal to VCM indicating crankshaft position and RPM. Information is used to determine when to pulse ignition coil, fuel injectors and control ignition timing. Conditions for setting DTC

Engine speed is less than 4000 RPM.
MAF sensor is at least 5 gm/s.
Crank sensor duty cycle is greater than 50 percent.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Check if engine starts. If engine starts, go to step 4 . If engine does not start, go to next step.
Clear DTCs. Crank engine for 10 seconds. Check if DTC P0338 resets. If DTC P0338 resets, go to next step. If DTC P0338 does not reset, see appropriate BASIC DIAGNOSTIC PROCEDURES article.
Install scan tool. Start engine and observe engine RPM on scan tool. If RPM fluctuates up to twice the expected RPM, go to step 14 . If RPM does not fluctuate up to twice the expected RPM, go to next step.
Disconnect crankshaft position sensor connector. Turn ignition on, with engine off. Using test light, probe signal circuit of crankshaft position sensor connector (engine harness side) to ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 8 .
Connect test light between ground circuit and signal circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
Turn ignition off. Install Gray jumper wires from Connector Test Kit (J-35616-A) between engine harness connector and crankshaft position sensor. Start engine. Using DVOM, check voltage on signal circuit. If voltage reading is 2-3 volts, go to step 16 . If voltage reading is not 2-3 volts, go to step 9 .
Turn ignition off. Disconnect VCM harness connector. Using test light connected to battery voltage, probe signal circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to step 11 . If test light does not illuminate, go to step 15 .
Check for open in signal circuit. If circuit is open, go to step 17 . If circuit is okay, go to next step.
Check for short to ground in signal circuit. If circuit is shorted, go to step 17 . If circuit is okay, go to step 13 .
Repair short to ground in ignition feed circuit. After repairs, go to step 19 .
Repair open in ground circuit. After repairs, go to step 19 .
Check for poor connection at crankshaft position sensor. If a problem is found, go to step 17 . If no problem is found, go to next step.
Replace crankshaft position sensor. After replacing sensor, go to step 19 .
Check for open in ignition feed circuit. If ignition feed circuit is open, go to step 17 . If circuit is okay, go to next step.
Check for poor connection at VCM. If connection is faulty, go to next step. If connection is okay, go to step 18 .
Repair circuit as necessary. After repairs, go to step 19 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0338: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT-HIGH FREQUENCY (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Engine speed less than 4000 RPM.
MAF at least 5 grams per second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine starts, go to step 4 . If engine does not start, go to next step.
Using scan tool, clear DTCs. Crank engine for 10 seconds and read DTCs. If DTC P0338 resets, go to next step. If DTC does not reset, go to NO START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Start engine. Using scan tool, monitor engine speed (RPM). If RPM fluctuates up to twice the desired RPM, go to step 14 . If RPM does not fluctuate, go to next step.
Turn engine off. Turn ignition on, with engine off. Disconnect CKP sensor harness connector. Connect a test light between engine ground and signal circuit at CKP sensor. If test light illuminates, go to next step. If test light does not illuminate, go to step 8 .
Connect test light between CKP sensor harness connector ground and signal circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
Turn ignition off. Install Gray jumpers from Connector Tester Kit (J-35616-A) between CKP sensor and CKP sensor harness connector. Using a DVOM, check voltage on CKP sensor harness connector signal circuit. If voltage reading is 2-3 volts, go to step 16 . If voltage reading is not as specified, go to step 9 .
Turn ignition off. Disconnect VCM harness connector. Connect test light between battery voltage and ignition feed circuit at CKP sensor. If test light does not illuminate, go to step 15 . If test light illuminates, go to step 11 .
Check for open in CKP sensor ground circuit. If circuit is open, go to step 17 . If circuit is okay, go to next step.
Check for short to ground in CKP sensor signal circuit. If circuit is shorted, go to step 17 . If circuit is okay, go to step 13 .
Repair short to ground in CKP sensor ignition feed circuit. After repairs, go to step 19 .
Repair open CKP sensor ground circuit. After repairs, go to step 19 .
Check for faulty connection at CKP sensor. If faulty connection is found, go to step 17 . If connection is okay, go to next step.
Replace CKP sensor. After replacing sensor, go to step 19 .
Check for open in CKP sensor harness connector ignition feed circuit. If circuit is open, go to step 17 . If circuit is okay, go to next step.
Check for faulty connection at VCM. If connection is faulty, go to next step. If connection is okay, go to step 18 .
Repair circuit as necessary. After repairs, go to step 19 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter this DTC. Operate vehicle within conditions required to set DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Check for faulty connections or damaged harness. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location.

DTC P0339: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT INTERMITTENT (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

MAF sensor is at least 5 gm/s.
Change in calculated engine speed is at least 1000 RPM.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Check if engine starts and continues to run. If engine starts and continues to run, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If engine does not start and or starts and stall, go to next step.
Turn ignition off. Disconnect crankshaft position sensor connector. Turn ignition on, engine off. Using test light connected to ground, probe ignition feed circuit of crankshaft position sensor connector (engine harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 6 .
Install test light between CKP sensor connector (engine harness side) ignition feed circuit and ground circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
Turn ignition off. Install Gray jumper wires from Connector Test Kit (J-35616-A) between engine harness connector and crankshaft position sensor. Set DVOM to duty cycle position. Connect DVOM between signal circuit and ground circuit of crankshaft position sensor connector (engine harness side). Crank engine. If duty cycle is 40-60 percent, go to step 8 . If duty cycle is not 40-60 percent, go to step 10 .
Repair open or short to ground in ignition feed circuit. After repairs, go to step 13 .
Check for open in ground circuit. If circuit is open, go to step 11 . If circuit is okay, go to step 9 .
With DVOM still connected, set DVOM to AC volt scale. Crank engine. If voltage reading is greater than 10 volts, go to step 11 . If voltage reading is not greater than 10 volts, go to next step.
Check for open in signal circuit or ground circuit. If circuit is open, go to step 11 . If circuit is okay, go to step 12 .
Replace crankshaft position sensor. Inspect sensor mounting surface and clean debris as necessary. After replacing sensor, go to step 13 .
Repair as necessary. After repairs, go to step 13 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Inspect face of crankshaft position sensor for metal shavings. Metal shavings could cause DTC P0339 to set. If DTC is intermittent, see appropriate TROUBLE SHOOTING - NO CODES article.

MAF at least 5 gm/s.
Change in calculated engine speed is at least 1000 RPM.
Calculated engine speed equals zero RPM and 4 or more CMP cycles have occurred for a period of 2-3 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
If engine starts and runs, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If engine does not start and run, go to next step.
Disconnect CKP sensor harness connector. Connect a test light between engine ground and ignition feed circuit at CKP sensor. Turn ignition on, engine off. If test light illuminates, go to next step. If test light does not illuminate, go to step 6 .
Connect test light between CKP sensor harness connector ground and ignition feed circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
Turn ignition off. Install Gray jumper wires from Connector Tester Kit (J-35616-A) between CKP sensor and sensor harness connector. Connect DVOM (set to duty cycle) between CKP sensor signal and ground circuits. Crank engine. If displayed duty cycle is 40-60 percent, go to step 8 . If duty cycle is not 40-60 percent, go to step 10 .
Repair open or short to ground in CKP sensor ignition feed circuit. After repairs, go to step 13 .
Check CKP sensor harness ground circuit for an open. If circuit is open, go to step 11 . If circuit is okay, go to step 9 .
Select DVOM AC volt scale. Crank engine. If voltage reading is greater than 10 volts, go to step 11 . If voltage reading is not greater than 10 volts, go to next step.
Check CKP sensor harness connector signal and ground circuits for an open. If circuit is open, go to step 11 . If circuit is okay, go to step 12 .
Ensure CKP sensor mounting surface is clean and free of debris. Replace CKP sensor. After replacing sensor, go to step 13 .
Repair as necessary. After repairs, go to step 13 .
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter this P0339. Operate vehicle within conditions required to set DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. Check if any undiagnosed DTCs are displayed. Diagnose affected DTCs. If no additional DTCs are displayed, system is okay.

Check for faulty connections or damaged harness. Observe scan tool while moving all related harnesses and connectors. A change in scan tool display indicates fault location. Inspect face of CKP sensor for metal shavings.

DTC P0340: CYLINDER DETECT SIGNAL MISSING (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

The Electronic Ignition (EI) module supplies a signal to the PCM whenever it determines that cylinder No. 4 fired on its compression stroke. Because of opposite coil tower polarity, the simultaneous firing of cylinders No. 1 and 4 are of opposite polarity as well. Under the most conditions, the waste spark cylinder fires before the compression cylinder in sequence. The EI module can determine this polarity sequence and voltage amplitude by using capacitive pickup plates located under cylinders No. 1 and No. 4 coil. If module senses a positive and negative sequence and high negative spike when cylinder No. 4 is on TDC, it pulls the PCM cam signal to ground signaling that cylinder No. 4 has just fired on compression. This signal along with the double pulse received from the CKP sensor, synchronizes spark and fuel timing.

DTC will set if the PCM voltage on cylinder No. 4 signal wire is not pulled to ground (cam signal pulse) when engine has been cranking for 5-10 seconds or when engine is running. Cam signal is continuously checked when crankshaft sensor pulses are received by the PCM, except under deceleration.

Connect scan tool. Start and operate engine for one minute. Using scan tool, check if DTC is active. If DTC is active, go to next step. If DTC is not active, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If engine misfire is present, check for a fault condition on cylinder No. 1 or No. 4. Check wires, plugs and cylinder compression. If engine misfire is not present, go to next step.
Install a jumper wire between IC module terminal "D" and harness connector. With engine running, observe 7X counter by using a test light. Connect test light to ground and momentarily touch jumper wire. Observe 7X counter on scan tool. If 7X counter resets to zero when touched by test light, check tightness of harness connector terminal to EI module or faulty EI module. If 7X counter does not reset to zero, go to next step.
Check cylinder No. 4 signal circuit between PCM and IC module terminal "D" for open, short to ground or short to voltage. Repair as necessary. If circuit is okay, check tightness of harness connector terminals to PCM.

When attempting to diagnose an intermittent problem, use scan tool to review malfunction history information. This data can be used to duplicate a problem.

DTC P0340: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Camshaft Position (CMP) sensor works in conjunction with a single-tooth reluctor wheel on bank 2 intake camshaft. ECM increases CMP sensor signal circuit to 12 volts and monitors this voltage. As reluctor wheel tooth rotates past sensor, sensor's internal circuitry pulls signal circuit to ground, creating a square wave signal used by ECM. Reluctor wheel tooth covers 180 degrees of camshaft circumference.

This causes CMP signal voltage to transition once per crankshaft revolution. This signal, when combined with CKP sensor signal, enables ECM to determine exactly which cylinder is on firing stroke. ECM can then properly synchronize ignition system, fuel injectors and knock control. Note that as long as CKP sensor signal is available, engine can start even if there is no CMP sensor signal. ECM will default to non-sequential fuel injection operation. Conditions required to set DTC are

CMP signal is incorrect for at least 500 milliseconds.
Engine has completed at least 100 revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start engine. Using scan tool, monitor Cam Signal Present. If scan tool indicates HIGH RANDOMLY, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If scan tool does not indicate HIGH RANDOMLY, go to next step.
Turn ignition off. Disconnect CMP sensor connector. Turn ignition on, with engine off. Using DVOM, check voltage between ground and CMP sensor harness connector switched battery feed circuit (ECM side). If battery voltage is present, go to next step. If battery voltage is not present, go to step 10 .
Using DVOM, measure voltage between ground and CMP sensor harness connector signal circuit (ECM side). If battery voltage is present, go to step 7 . If battery voltage is not present, go to next step.
Turn ignition off. Disconnect ECM harness connector located in engine compartment, in relay center. Using DVOM, check harness continuity of CMP sensor signal circuit. If continuity exists, go to next step. If continuity does not exist, go to step 12 .
Using DVOM, check harness continuity between ground and CMP sensor signal circuit. If continuity exists, go to step 11 . If continuity does not exist, go to step 16 .
Using test light connected to battery voltage, probe CMP sensor harness connector ground circuit (ECM side). If test light is on, go to step 9 . If test light is off, go to next step.
Turn ignition off. Disconnect ECM connector located in engine compartment relay center. Using DVOM, check harness continuity of CMP sensor harness connector ground circuit. If continuity exists, go to step 16 . If continuity does not exist, go to step 13 .
Connect Signal Generator Tester (J-33431-B) to CMP sensor harness connector (ECM side). Turn ignition on. Turn tester on and set to generate a 54 MPH signal. Using scan tool, monitor Cam Signal Present. If scan tool indicates HIGH RANDOMLY, go to step 14 . If scan tool does not indicate HIGH RANDOMLY, go to step 16 .
Repair switched battery feed circuit. After repairs, go to step 18 .
Repair short to ground in signal circuit. After repairs, go to step 18 .
Repair open or high resistance in signal circuit. After repairs, go to step 18 .
Repair open or high resistance in ground circuit. After repairs, go to step 18 .
Check for poor connection and terminal tension at CMP sensor harness connector. Check CMP sensor for proper installation. A sensor that is loose or not fully seated could cause an excessive air gap between CMP sensor and reluctor wheel. Repair as necessary. After repairs, go to step 18 . If connections and terminals are okay, go to next step.
Replace CKP sensor. After replacing sensor, go to step 18 .
Check for poor connection and terminal tension at ECM harness connector. Repair as necessary. After repairs, go to step 18 . If connections and terminals are okay, go to next step.
Replace ECM. NEW ECM must be programmed with theft deterrent module frequency code currently on vehicle. After replacing ECM, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0340 is set, go to step 2 . If DTC P0340 is not set, go to next step.
If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.

Check CMP sensor for proper installation. A sensor that is loose or not fully seated, causing an excessive air gap between sensor and reluctor wheel, may cause this DTC to set.

DTC P0340: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT (3.5L "W" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

The Camshaft Position (CMP) sensor signal, when combined with the CKP sensor signal, enables the PCM to determine exactly which cylinder is on a firing stroke. PCM can then properly synchronize the ignition system, fuel injectors and knock control. PCM supplies 12 volts to sensor. Power and reference low circuits are also connected to CKP sensor. DTC will set when PCM detects a problem with the CMP sensor signal.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start engine. If engine starts and runs, go to next step. If engine does not start or starts but stalls/dies, go to step 7 .
Start engine. Using scan tool, select CMP SENSOR and CAM SIGNAL PRESENT data. If scan tool indicates that RPM and CAM signal is present, go to next step. If scan tool does not indicate that RPM and CAM signal is present, go to step 5 .
Wiggle related harnesses and connectors while monitoring scan tool display. If CAM SIGNAL PRESENT display changes to NO or if CMP sensor data RPM becomes erratic, go to step 13 . If CAM SIGNAL PRESENT display does not changes to NO or if CMP sensor data RPM does not becomes erratic, fault is not present. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect CMP sensor harness connector. Turn ignition on. Using DVOM, check voltage between ground and CMP sensor power circuit at sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 14 .
Check voltage between ground and power circuit at CMP sensor harness connector. If battery voltage is present, go to step 9 . If battery voltage is not present, go to step 15 .
Turn ignition off. Disconnect CMP sensor harness connector. Turn ignition on. Check voltage between ground and power circuit at CMP sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 21 .
Check voltage between power circuit and REF LO circuit at CMP sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 22 .
Using scan tool, monitor CAM sensor data. Using a test light connected to battery voltage, momentarily touch test light to signal circuit several times. If RPM is indicated on scan tool, go to step 19 . If RPM is not indicated on scan tool, go to next step.
Turn ignition off. Disconnect PCM harness connector C1. Turn ignition on. Using DVOM, check voltage on sensor signal circuit. If voltage is indicated, go to step 18 . If voltage is not indicated, go to next step.
Check resistance in signal circuit between CMP sensor harness connector and PCM harness connector. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 16 .
Check resistance between ground and sensor signal circuit. If resistance is infinite, go to step 23 . If resistance is not infinite, go to step 17 .
Repair harness/connections as necessary. After repairs, go to step 25 .
Repair open or high resistance in power circuits. After repairs, go to step 25 .
Repair open/high resistance in ground circuit. After repairs, go to step 25 .
Repair open/high resistance in sensor signal circuit. After repairs, go to step 25 .
Repair sensor signal circuit shorted ground. After repairs, go to step 25 .
Repair sensor signal circuit shorted to power. After repairs, go to step 25 .
Check for poor connections at CMP sensor. Repair as necessary. After repairs, go to step 25 . If connections are okay, go to next step.
Replace CMP sensor. After replacing sensor, go to step 25 .
Check power circuit for open/high resistance between PCM and splice or check for short to ground. Repair as necessary. After repairs, go to step 25 . If circuit is okay, go to step 23 .
Check ground circuit for open/high resistance between PCM and splice. Repair as necessary. After repairs, go to step 25 . If circuit is okay, go to next step.
Check poor connections/terminal tension at PCM. Repair as necessary. After repairs, go to step 25 . If connections are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURED INFO. Check if any undiagnosed DTCs are displayed. Diagnose affected DTCs. If no additional DTCs are displayed, system is okay.

Check CMP sensor for proper installation. A sensor that is loose or not fully seated, causing an excessive air gap between sensor and reluctor wheel, may cause this DTC to set.

DTC P0340: IGNITION CONTROL (IC) MODULE CAM REFERENCE CIRCUIT-NO FREQUENCY (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

This test checks for camshaft pulses not received when 4X reference pulses are being received. This indicates that a camshaft sensor circuit failure and DTC will set. Conditions for setting DTC

DTC P0322 not set.
4X reference pulses being received.
Engine speed 1600 RPM or less.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Using scan tool, check if DTC P1376 is also present. If DTC P1376 is present, diagnose DTC first. If DTC P1376 is not present, go to next step.
Turn ignition off. Disconnect IC module connector C2. Using DVOM, check resistance between camshaft position sensor harness connector terminals. If resistance is 800-2100 ohms, go to next step. If resistance is not as specified, go to step 6 .
Individually check resistance to ground at both IC module harness connector terminals. If resistance at either terminals is less than 100 ohms, go to step 12 . If not, go to next step.
Disconnect IC module connector C3. Set DVOM to "peak min/max", 4-volt scale. Connect DVOM across camshaft position sensor harness connector terminals. Crank engine. If DVOM reads greater than 0.2 volt, go to step 9 . If DVOM does not read greater than 0.2 volt, go to step 17 .
If resistance is less than 800 ohms, go to next step. If resistance is not less than 800 ohms, go to step 8 .
Disconnect camshaft position sensor connector. Check resistance between sensor harness connector terminals. If resistance is greater than 10,000 ohms, go to step 17 . If resistance is not greater than 10,000 ohms, go to step 13 .
Disconnect camshaft position sensor. Individually check continuity in sensor low and high signal circuits. If continuity is present on both circuits, go to step 17 . If continuity is not present on both or either circuits, go to step 14 .
Reconnect IC module harness connector C2. Disconnect IC module harness connector C4. Using scan tool, store fluid life index as indicated. Turn ignition off and wait 30 seconds, then disconnect PCM harness connector C2. Using DVOM, check resistance between ground camshaft position sensor signal circuit at PCM harness connector terminal. If resistance is less than 10,000 ohms, go to step 16 . If resistance is not less than 10,000 ohms, go to next step.
Check resistance between camshaft position sensor signal circuit at PCM harness connector terminal. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, go to step 15 .
Reconnect IC module connectors C3 and C4. Using DVOM, set DVOM to "peak min/max" 4-volt DC scale and push HERTZ button. Connect DVOM between IC module harness connector terminal "B" (cam signal circuit) and ground. Crank engine. If frequency reading is greater than 0.4 Hz, go to step 21 . If frequency reading is not greater than 0.4 Hz, go to step 19 .
Repair short to ground in camshaft position sensor circuits between sensor and IC module harness connector.
Repair short between camshaft position sensor circuits.
Repair open or high resistance in camshaft position sensor circuits.
Repair open in cam signal circuit to PCM.
Repair short to ground in cam signal circuit to PCM.
Check terminal contact at camshaft position sensor terminal. Repair as necessary. If terminal contacts are okay, go to next step.
Replace camshaft position sensor.
Check terminal contact at IC module. Repair as necessary. If terminal contact is okay, go to next step.
Replace IC module.
Check terminal contact to cam signal circuit at PCM connector. Repair as necessary. If terminal contact is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment.

DTC P0340: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Camshaft Position (CMP) sensor is used to indicate camshaft position so that VCM can determine which cylinder is misfiring when misfire is present. Sensor also checks if high voltage switch is properly installed. DTC will set when engine is running and camshaft position sensor reference pulse is not seen once every 2 revolutions of crankshaft.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Install scan tool. With engine idling, record FREEZE FRAME and FAILURE RECORDS for DTC. Wait one minute with engine idling. Observe LAST TEST FAILED for DTC recorded in FREEZE FRAME. If failed, turn engine off and restart. Check if Malfunction Indicator Light (MIL) is illuminated. If MIL is illuminated, go to next step. If MIL is not illuminated, go to step 8 .
Turn ignition off. Disconnect camshaft position sensor connector. Turn ignition on, with engine off. Using a test light, probe ignition feed circuit of camshaft position sensor connector (engine harness side) to ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 9 .
Connect test light between ground circuit and ignition feed circuit of camshaft position sensor connector (engine harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 11 .
Turn ignition off. Install Gray jumper wires from Connector Test Kit (J-35616-A) between engine harness connector and camshaft position sensor. Start engine. Using DVOM, check voltage on signal circuit. If voltage reading is 5-7 volts, go to step 15 . If voltage reading is not 5-7 volts, go to next step.
Check for open in camshaft position sensor signal circuit. If a problem is found, go to step 13 . If no problem is found, go to next step.
Check for short to ground in signal circuit. If a problem is found, go to step 13 . If no problem is found, go to step 12 .
DTC is intermittent. If no additional DTCs are set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) . If any additional DTCs are set, go to applicable DTC test.
Check for open in ignition feed circuit. If ignition feed circuit is open, go to step 13 . If circuit is okay, go to next step.
Repair short to ground in ignition feed circuit. After repairs, go to step 17 .
Repair open in ground circuit. After repairs, go to step 17 .
Check for poor connection at camshaft position sensor. If a problem is found, go to next step. If no problem is found, go to step 14 .
Repair circuit as necessary. After repairs, go to step 17 .
Replace camshaft position sensor. After replacing sensor, go to step 17 .
Check for poor connection at VCM connector. If a connection problem is found, go to step 13 . If no problem is found, go to next step.
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0340: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Camshaft Position (CMP) sensor is used to indicate camshaft position so that VCM can determine which cylinder is misfiring if misfire is present. CMP sensor also checks for properly installed high voltage switch. DTC will set when engine is running and CMP sensor reference pulse is not seen once every 6 revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Retrieve and record FREEZE FRAME and FAILED RECORDS data for this DTC. Continue to idle engine for one minute. Observe FREEZE FRAME, LAST TEST FAILED DTC. If this DTC P0340 FAILED is not displayed, go to step 8 . If DTC P0340 FAILED is displayed, turn engine off. Restart engine. If MIL remains on, go to next step. If MIL does not remain on, go to step 8 .
Turn ignition on, with engine off. Disconnect CMP sensor harness connector. Connect a test light between engine ground and CKP sensor harness connector ignition feed circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 9 .
Connect test light between CMP sensor harness connector ground and ignition feed circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 11 .
Turn ignition off. Install Gray jumper wire from Connector Test Kit (J-35616-A) between CMP sensor and CMP sensor harness connector. Using a DVOM, check voltage between on CMP sensor signal circuit. If voltage reading is 5-7 volts, go to step 15 . If voltage reading is not 5-7 volts, go to next step.
Check CMP sensor harness connector signal circuit for open. If circuit is open, go to step 13 . If circuit is not open, go to next step.
Check CMP sensor harness connector signal circuit for short to voltage. If circuit is shorted, go to step 13 . If circuit is not shorted, go to step 12 .
DTC is intermittent. Check if any additional DTCs are set. Diagnose affected DTCs. If no additional DTCs are set, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Check for open in CMP sensor harness connector ignition feed circuit. If circuit is open, go to step 13 . If circuit is okay, go to next step.
Repair short to ground in CMP sensor harness connector ignition feed circuit. After repairs, go to step 17 .
Repair open in CMP sensor harness connector ground circuit. After repairs, go to step 17 .
Check for faulty connection at CMP sensor. If connection is faulty, go to next step. If connection is okay, go to step 14 .
Repair circuit as necessary. After repairs, go to step 17 .
Replace CMP sensor. After replacing sensor, go to step 17 .
Check for faulty connection at VCM harness connector. If connection is faulty, go to step 13 . If connection is okay, go to next step.
Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter this DTC. Operate vehicle within conditions required to set DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Check for faulty connections or damaged harness. Observe scan tool while moving all related harnesses and connectors. A change in scan tool display indicates fault location.

DTC P0341: CYLINDER DETECT SIGNAL ERROR-TOO MANY PULSES (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

The Electronic Ignition (EI) module supplies a signal to the PCM whenever it determines that cylinder No. 4 fired on its compression stroke. Because of opposite coil tower polarity, the simultaneous firing of cylinders No. 1 and 4 are of opposite polarity as well. Under most conditions, the waste spark cylinder fires before the compression cylinder in sequence. The EI module can determine this polarity sequence and voltage amplitude by using capacitive pick-up plates located under cylinder No. 1 and 4 coils. If module senses a positive and negative sequence and high negative spike when cylinder No. 4 is on TDC, it pulls the PCM cam signal to ground, signaling that cylinder No. 4 has just fired on compression. This signal, along with the double pulse received from the CKP sensor, synchronizes spark and fuel timing.

Only one cylinder No. 4 signal should be received every 14 crank pulses. DTC will set if cam signal received at the PCM is incorrect or has too many pulses per crankshaft revolution when engine has been cranking for 5-10 seconds or when engine is running. Cam signal is continuously checked when crankshaft sensor pulses are received by the PCM, except under deceleration.

Connect scan tool. Start and operate engine for one minute. Using scan tool, check if DTC is active. If DTC is active, go to next step. If DTC is not active, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If engine misfire is present, diagnose using misfire DTCs test, then retest for DTC P0341. If engine misfire is not present, go to next step.
Turn ignition off. Disconnect PCM harness connector J3 and remove cylinder No. 4 signal circuit from PCM harness connector. Reconnect PCM harness connector. Start and operate engine for one minute. If DTC P0341 resets, replace PCM. If DTC P0341 does not reset, go to next step.
Turn ignition off. Disconnect EI module harness connector. Check resistance between cylinder No. 4 signal circuit and ground. If circuit is not open, repair short to ground in circuit. If circuit is open, check for intermittent short to ground in circuit. If circuit is not shorted, replace EI module.

When attempting to diagnose an intermittent problem, use scan tool to review malfunction history information. This data can be used to duplicate a problem.

If an open circuit exists on cylinder No. 4, DTC will set, due to polarity and amplitude of the coil during every firing event looking as if cylinder No. 4 is on compression. The PCM thinks cylinder No. 4 is on compression every crankshaft revolution. If engine is misfiring, refer to misfire DTCs for diagnosis. High resistance in the spark plug, wires or connections will also set DTC.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT (2.2L "J" BODY & "S" SERIES & 2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) uses CMP sensor signal to determine which cylinder is misfiring when a misfire is present. When PCM receives an intermittent signal from CMP sensor, the CMP RESYNC counter will increment. Conditions for setting this DTC are as follows

Engine is running.
CMP RESYNC counter is greater than 15 counts in less than 256 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and allow engine to idle. Install scan tool. If CMP RESYNC counter is incrementing, go to next step. If CMP RESYNC counter is not incrementing, go to step 4 .
Turn ignition off. Disconnect CMP sensor connector. Turn ignition on. If CMP RESYNC counter is incrementing, go to step 5 . If CMP RESYNC counter is not incrementing, go to step 6 .
With engine running, carefully wiggle CMP sensor connector. If CMP RESYNC counter is incrementing, go to next step. If CMP RESYNC counter is not incrementing, go to step 9 .
Check for poor connection at CMP sensor connector. Repair as necessary. After repairs, go to step 10 . If connector is okay, go to step 7 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 10 .
Turn ignition off. Disconnect PCM harness connector. Check CMP terminal at PCM harness connector for poor connection. Repair as necessary. After repairs, go to step 10 . If connections are okay, go to next step.
Replace CMP sensor. After replacing sensor, go to step 10 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If CMP RESYNC counter is incrementing, go to step 3 . If CMP RESYNC counter is not incrementing, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0341. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

An intermittent problem can be caused by a poor connection, rubbed-through wire insulation or broken wire inside insulation. Whenever PCM sees less than 15 resyncs in 256 seconds, counter is reset to zero. If a poor CMP sensor connection is present, CAM SENSOR REFERENCE ACTIVITY counter will stop incrementing and CAM SENSOR RESYNC counter will start incrementing.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT PERFORMANCE (3.0L "V" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Inspect CMP sensor harness routing. Ensure harness does not interfere with high voltage sources. If a problem is found, go to next step. If harness routing is okay, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Reroute wire harness as necessary. After repairs, go to next step.
Using scan tool, clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0341. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, go to step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, system is okay.

Check CMP sensor for proper installation. A sensor that is loose or not fully seated, causing an excessive air gap between sensor and reluctor wheel, may cause this DTC to set.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC P0341 will set if Camshaft Position (CMP) sensor pulses are not in proper ratio to 24X and 3X pulses. Conditions required to set DTC are

Engine running and PCM receiving 3X reference pulses.
CMP reference pulse signal not detected in every engine cycle.
Conditions present for 30 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Using scan tool, read and record FAILURE RECORDS data for DTC P0341. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0341 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0341 FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect PCM harness connectors. Connect a test light between battery voltage and PCM harness connector sensor feed circuit. If test light illuminates, leave test light connected and go to next step. If test light does not illuminate, go to step 6 .
Disconnect CMP sensor connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 11 .
Check for short to ground in CMP and 24X CKP sensors feed circuit. Repair as necessary. After repairs, go to step 14 . If circuit is okay, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Connect a fused jumper wire between PCM harness connector sensor feed circuit and battery voltage. Using a DVOM, check voltage between engine ground and PCM harness connector CMP signal circuit. If voltage reading is near battery voltage, leave fused jumper wire connected and go to next step. If voltage reading is not near battery voltage, go to step 8 .
Check voltage between engine ground and PCM harness connector sensor ground circuit. If voltage reading is near battery voltage, go to step 12 . If voltage reading is not near battery voltage, go to step 10 .
Check for open CMP sensor feed circuit. If circuit is open, repair as necessary. After repairs, go to step 14 . If circuit is okay, go to next step.
Check for open or short in CMP sensor signal circuit. Repair as necessary. After repairs, go to step 14 . If circuit is okay, go to step 11 .
Check for open CMP sensor ground circuit. Repair as necessary. After repairs, go to step 14 . If circuit is okay, go to next step.
Replace CMP sensor. After replacing sensor, go to step 14 .
Check for faulty connections at PCM. If a faulty connection is found, repair as necessary. After repairs, go to step 14 . If connections are okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Read and record FAILURE RECORDS data for DTC P0336. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0336 FAILED THIS IGN, repeat step 2 . If scan tool does not display DTC P0336 FAILED THIS IGN, repair is complete.

Check for faulty connections or damaged harness. Observe a voltmeter connected to CMP sensor signal circuit at PCM harness connector while moving all related harness and connectors. A change in voltage indicates fault location.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT PERFORMANCE (3.8L "C", "F", "G", "H" & "W" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC P0341 will set if Camshaft Position (CMP) sensor pulses are not in proper ratio to 18X and 3X pulses. Conditions required to set DTC are

Engine running and PCM receiving 3X reference pulses.
Ratio of 3X reference pulses to CMP pulses received by PCM does not equal 6.
Ratio of 18X reference pulses to 3X reference pulses received by PCM does not equal 6.
Conditions present for 600 engine revolutions.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Using scan tool, read and record FAILURE RECORDS data for DTC P0341. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0341 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0341 FAILED THIS IGN, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect PCM harness connectors. Using DVOM, check voltage on CMP sensor signal circuit at PCM harness connector. Turn ignition on. If voltage reading is about 5 volts, go to next step. If voltage reading is not about 5 volts, go to step 5 .
Remove CMP sensor, leaving harness connector connected. Place a magnet on sensor. If voltage reading is now about zero volts, go to step 16 . If voltage reading is not about zero volts, go to step 8 .
If voltage reading is greater than 5 volts, go to step 7 . If voltage reading is not greater than 5 volts, go to next step.
Turn ignition off. Disconnect Ignition Control Module (ICM) harness connector. Leave PCM harness connector disconnected. Turn ignition on. Connect a test light between battery voltage and ICM harness connector CMP sensor signal and CMP sensor input circuits. If test light illuminates, locate and repair short to ground in CMP sensor signal or input circuit and go to step 24 . If test light does not illuminate, go to step 13 .
Turn ignition off. Disconnect Ignition Control Module (ICM) harness connector. Leave PCM harness connector disconnected. Turn ignition on. Connect a test light between engine ground and ICM harness connector CMP sensor input circuit. If test light illuminates, locate and repair short to voltage in CMP sensor input circuit. After repairs, go to step 24 . If test light does not illuminate, go to step 18 .
Disconnect CMP sensor. Check voltage between CMP sensor harness connector sensor feed and sensor ground circuit. If voltage reading is about battery voltage, go to next step. If voltage reading is not about battery voltage, go to step 12 .
Check voltage CMP sensor harness connector sensor signal and sensor ground circuits. If voltage reading is 5-7 volts, go to next step. If voltage reading is not 5-7 volts, go to step 11 .
Check voltage on PCM harness connector CMP sensor input signal circuit. Connect a test light to CMP sensor harness connector sensor signal circuit. Repeatedly touch other end of test light to engine ground. If voltage switches from zero to 5 volts, go to step 15 . If voltage does not switch, go to step 14 .
Turn ignition off. Disconnect Ignition Control Module (ICM) connector. Leave CMP sensor connector disconnected. Turn ignition on. Check CMP sensor signal circuit for open or short to voltage. Check CMP sensor input signal circuit for short to voltage. Repair as necessary. After repairs, go to step 24 . If no problem is found, go to step 14 .
Turn ignition off. Disconnect ICM and CMP sensor connectors. Check sensor feed and sensor ground circuits for open between ICM and CMP sensor. Repair as necessary. After repairs, go to step 24 . If no problem is found, go to step 14 .
Check for open in CMP sensor input signal circuit between ICM and PCM. Repair as necessary. After repairs, go to step 24 . If circuit is okay, go to next step.
Check for faulty connection at ICM. Repair as necessary. After repairs, go to step 24 . If ICM connection is okay, go to step 17 .
Check for faulty connection at CMP sensor. Repair as necessary. After repairs, go to step 24 . If connection is okay, go to step 19 .
Check for faulty connection at PCM. Repair as necessary. After repairs, go to step 24 . If PCM connection is okay, go to step 20 .
Check for incorrect harness routing near secondary ignition components, ignition coil arcing to wiring harness or ICM. Check ignition coils for cracks, carbon tracking or other signs of damage. Check for secondary ignition wire(s) arcing to wiring harness. Repair as necessary. After repairs, go to step 24 . If no problem is found, go to next step.
Replace ICM. After replacing module, go to step 24 .
Replace CMP sensor. After replacing sensor, go to step 24 .
Check for incorrect harness routing near secondary ignition components, ignition coil arcing to wiring harness or ICM. Check ignition coils for cracks, carbon tracking or other signs of damage. Check for secondary ignition wire(s) arcing to wiring harness. Repair as necessary. After repairs, go to step 24 . If no problem is found, go to next step.
Reinstall CMP sensor. Using DVOM, check voltage on CMP sensor input signal circuit while cranking engine. If voltage switches from zero to 4 volts, go to next step. If voltage does not switch, go to step 23 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to step 24 .
Replace faulty or missing CMP sensor. After repairs, go to next step.
Read and record FAILURE RECORDS data for DTC P0341. Clear DTCs. Operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0341 FAILED THIS IGN, repeat step 2 . If scan tool does not display DTC P0341 FAILED THIS IGN, repair is complete.

Check for faulty connections or damaged harness. Observe a voltmeter connected to CMP sensor input circuit at PCM harness connector while moving all related harness and connectors. A change in voltage indicates fault location.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT PERFORMANCE (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

If cam/crank sensor pulse ratio is skewed, DTC will set. Fault is not a solid or consistent failure and may not act the same way twice. DTC will set when engine is running, and CMP sensor reference pulse is not detected at correct interval.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Check for intermittent short to voltage or electromagnetic interference (i.e., wires running along side spark plug wires, high power transmitters such as mobile radios) in camshaft position sensor wires. If a problem is found, go to next step. If no problem is found, go to step 4 .
Repair short to voltage or EMI interference as necessary. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT (4.3L "L", "M", "S" & "T" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC P0341 will set if cam pulses are not in proper ratio to crank pulses. Conditions for setting DTC

Engine running.
Cam sensor reference pulse is not detected at correct interval.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Check for intermittent short to voltage or Electromagnetic Interference (EMI) on CMP sensor wires such as wires run alongside spark plug wires or high power transistors (like mobile radios operating nearby). If problem is found, go to next step. If no problem is found, go to step 4 .
Repair short to voltage or correct EMI interference. After repairs, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter this DTC. Operate vehicle within conditions required to set DTC. If scan tool indicates that this DTC RAN AND PASSED, go to next step. If scan tool does not indicate that this DTC RAN AND PASSED, repeat step 2 .
Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.

Check for faulty connections or damaged harness. Observe scan tool while moving all related harness and connectors. A change in scan tool display indicates fault location.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT PERFORMANCE (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Camshaft Position (CMP) sensor is mounted on top of engine block at rear of valley cover. CMP works in conjunction with CMP reluctor (1X). Reluctor is located on inside engine, immediately in front of rear cam bearing. CMP sensor is used to determine whether a cylinder is on a firing or exhaust stroke. As camshaft rotates, reluctor wheel interrupts a magnetic field produced by magnet inside sensor. Sensor produces signal sent to PCM. PCM uses 1X signal along with CKP sensor 24X signal to determine crankshaft position and stroke. A slightly longer cranking time may be a symptom of this DTC.

DTC will set when PCM detects that a CMP to CKP mismatch has occurred.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle for 2 minutes. Using scan tool, monitor FAILED THIS IGNITION display under DTC P0341. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Visually inspect CMP sensor circuits for routing too close to secondary ignition components, after-market components, solenoids, relays and motors. Repair as necessary. After repairs, go step 8 . If routing is okay, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Check for poor connections/terminal tension at CMP sensor. Repair as necessary. After repairs, go to step 8 . If connection or terminal tension is okay, go to next step.
Check for poor CMP sensor circuit connections/terminal tension at PCM. Repair as necessary. After repairs, go to step 8 . If connection or terminal tension is okay, go to next step.
Remove CMP and inspect sensor. Replace CMP sensor if necessary. If CMP sensor is okay, go to next step.
Replace CMP sensor. After replacing sensor, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for poor connections/terminal tension at CMP sensor. Check for damaged camshaft reluctor wheel or for improper installation. Check engine front cover assembly for damage or sensor coming in contact with reluctor wheel.

DTC P0341: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT PERFORMANCE (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Ignition voltage is 5-17 volts.
Engine speed is less than 4000 RPM.
PCM detects CMP-to-CKP mismatch has occurred for 10 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle for 2 minutes. Using scan tool, monitor FAILED THIS IGNITION display under DTC P0341. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Visually inspect CMP sensor circuits for routing too close to secondary ignition components, after-market components, solenoids, relays and motors. Repair as necessary. After repairs, go step 9 . If routing is okay, go to next step.
Check for poor connections/terminal tension at CMP sensor. Repair as necessary. After repairs, go to step 9 . If connection or terminal tension is okay, go to next step.
Check for poor CMP sensor circuit connections/terminal tension at PCM. Repair as necessary. After repairs, go to step 9 . If connection or terminal tension is okay, go to next step.
Remove CMP and inspect sensor. Replace CMP sensor if necessary. If CMP sensor is okay, go to next step.
Visually inspect CMP sensor reluctor wheel for damage. Replace or repair reluctor wheel as necessary. If reluctor wheel is okay, go to next step.
Replace CMP sensor. After replacing sensor, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0341. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0342: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT LOW (2.2L "J" BODY & "S" SERIES & 2.4L "J" & "N" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Powertrain Control Module (PCM) uses CMP sensor signal to determine which cylinder is misfiring when a misfire is present. When PCM receives an intermittent signal from CMP sensor, the CMP ACTIVITY counter will increment. Conditions for setting this DTC are as follows

Engine is running.
CMP ACTIVITY counter does not increment.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start engine and allow it to idle. Install scan tool. If CMP ACTIVITY counter is incrementing, go to next step. If CMP ACTIVITY counter is not incrementing, go to step 4 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME data and note parameters. Start engine and operate vehicle within conditions required for setting this DTC, and as close to conditions recorded in FREEZE FRAME as possible. If CMP ACTIVITY counter is incrementing, go to step 16 . If CMP ACTIVITY counter is not incrementing, go to next step.
Disconnect CMP sensor connector. With test light connected to ground, probe CMP feed circuit terminal at CMP sensor harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 6 .
With test light connected to positive battery terminal, probe CMP ground circuit terminal at CMP sensor harness connector. If test light illuminates, go to step 7 . If test light does not illuminate, go to step 8 .
Check for poor connection at CMP feed circuit at PCM connector. Repair as necessary. After repairs, go to step 16 . If connection is okay, go to step 15 .
Reconnect CMP harness sensor connector. Turn ignition off. Disconnect PCM C2 harness connector. Connect a jumper wire between positive battery terminal and ignition feed circuit terminal at PCM C2 harness connector. With DVOM connected to ground, probe CMP signal circuit terminal at PCM connector. If voltage reading varies from zero volts to battery voltage, go to step 15 . If voltage reading does not vary from zero volts to battery voltage, go to step 9 .
Check for poor connection or open in CMP ground circuit. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to step 15 .
If DVOM reading in step 7 is a constant voltage (either zero or battery voltage), go to next step. If voltage reading is not a constant voltage, go to step 11 .
Check for a short to voltage in CMP signal circuit. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to step 14 .
Disconnect CMP sensor connector. With DVOM connected to positive battery terminal, probe CMP signal circuit terminal at CMP sensor harness connector. If voltage reading is greater than 0.5 volt, go to next step. If voltage reading is not greater than 0.5 volt, go to step 13 .
Repair short to ground in CMP signal circuit. After repairs, go to step 16 .
Check for poor connection or an open in CMP signal circuit. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to next step.
Replace CMP sensor. After replacing sensor, go to step 16 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function then enter DTC P0342. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step 2 .
If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.

DTC P0342: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT-LOW VOLTAGE (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC will set when PCM detects that CMP signal is stuck low when signal should be high for 1.5 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, select CAM SIGNAL INPUT and monitor HIGH/LOW TRANSITION counter. If counter is incrementing, go to next step. If counter is not incrementing, go to step 4 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter this DTC. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect CMP sensor harness connector. Turn ignition on, with engine off. Using s DVOM, check voltage between ground and CMP sensor ignition feed circuit. If battery voltage is present, go to next step. If battery voltage is not present, go to step 7 .
Check voltage between CMP sensor ignition feed and ground circuit at harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 9 .
Start engine. Connect a test light to battery voltage. Using scan tool in ENGINE DATA LIST 1 function, monitor CAM signal input high-to-low and low-to-high transition counter while momentarily and repeatedly probing test light to sensor signal circuit. If transition counters increment when test light makes contact, go to step 15 . If transition counters does not increment when test light makes contact, go to step 10 .
Turn ignition off. Disconnect PCM harness connector. Using a DVOM, check continuity and resistance in ignition feed circuit. If continuity exists and resistance is 0-5 ohms, go to next step. If continuity does not exist and resistance is not 0-5 ohms, go to step 12 .
Check for poor connection or grounded circuit at CMP sensor ignition feed circuit. Repair as necessary. After repairs, go to step 19 . If circuit is okay, go to step 16 .
Turn ignition off. Disconnect PCM harness connector C1. Using DVOM, check continuity and resistance of CMP sensor ground circuit. If continuity exists and resistance is 0-5 ohms, go to step 16 . If continuity does not exists and resistance is not 0-5 ohms, go to step 13 .
Turn ignition off. Disconnect PCM harness connector C1. Using DVOM, check continuity and resistance of CMP sensor signal circuit. If continuity exists and resistance is 0-5 ohms, go to next step. If continuity does not exist and resistance is not 0-5 ohms, go to step 14 .
Turn ignition on, with engine off. Check for grounded or shorted to voltage in CMP signal circuit. Repair as necessary. After repairs, go to step 19 . If circuit is okay, go to step 16 .
Check for open in CMP sensor ignition feed circuit. Repair as necessary. After repairs, go to step 19 . If circuit is okay, go to step 16 .
Repair open in CMP sensor ground circuit. After repairs, go to step 19 .
Repair open in CMP sensor signal circuit. After repairs, go to step 19 .
Check for poor connections at CMP harness connector. Repair as necessary. After repairs, go to step 19 . If connections are okay, go to step 17 .
Check for poor connections at PCM harness connector. Repair as necessary. After repairs, go to step 19 . If connections are okay, go to step 18 .
Replace CMP sensor. After replacing sensor, go to step 19 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0342: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT-LOW VOLTAGE (5.7L "F" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Ignition voltage is 9-17 volts.
Engine speed is less than 4000 RPM.
PCM detects CMP signal is stuck low when signal should be high for 5 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor CAM signal input High-To-Low and Low-To-High transition parameter in ENGINE DATA LIST 1. If scan tool parameter increments, go to next step. If scan tool parameter does not increment, go to step 4 .
Turn ignition on, engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data for this DTC and observe parameters. Turn ignition off for 15 seconds. Start and operate engine at idle. Operate vehicle within conditions required for this DTC to set. Select DTC option, SPECIFIC DTC option and enter DTC P0342. If scan tool indicates that this DTC failed this ignition, go to next step. If scan tool does not indicate that this DTC failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect CMP jumper harness connector located near EGR valve. Turn ignition on, engine off. Using Brown terminal from Terminal Kit (J-35616-A), install terminal into CMP sensor ignition feed circuit on PCM harness side. Using DVOM, check voltage between CMP sensor ignition feed circuit and battery ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 14 .
Check voltage between CMP sensor ignition feed circuit and CMP sensor ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 16 .
Start engine. Using scan tool in ENGINE DATA LIST 1, monitor CAM signal input High-To-Low and Low-To-High transition. Momentarily and repeatedly probe signal circuit using a fused jumper wire connected to battery voltage. If CAM signal input increments when jumper contacts signal circuit, go to next step. If CAM signal input does not increment, go to step 17 .
At the CMP jumper harness, jumper ignition feed and ground circuit between PCM side of harness to CMP sensor side of harness. Connect a third jumper to signal circuit of CMP sensor side of harness. Start and operate engine at idle. Set DVOM to DC scale and duty cycle position. Connect DVOM between ground and CMP sensor signal circuit. If DVOM reads 45-55 percent, go to next step. If DVOM does not read 45-55 percent, go to step 9 .
Check PCM to CMP sensor jumper harness for proper connection. Repair as necessary. After repairs, go to step 35 . If connection is okay, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Remove intake manifold. Disconnect and the reconnect CMP sensor harness connector. Turn ignition on, engine off. Check voltage between CMP sensor ignition feed circuit and battery ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 19 .
Check voltage between CMP sensor ignition feed circuit and sensor ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 21 .
Disconnect CMP sensor jumper harness connector. Check continuity of CMP signal circuit. If continuity is present or resistance is 0-5 ohms, go to next step. If continuity is not present or resistance is not 0-5 ohms, go to step 23 .
Check voltage between ground and CMP signal circuit. If voltage reading is less than one volt, go to next step. If voltage reading is not less than one volt, go to step 25 .
Using a test light connected to battery voltage, probe CMP signal circuit. If test light illuminates, go to step 26 . If test light does not illuminate, go to step 31 .
Turn ignition off. Disconnect PCM harness connector. Check continuity of CMP ignition feed circuit. If continuity exists or resistance is 0-5 ohms, go to next step. If continuity does not exist or resistance is not 0-5 ohms, go to step 28 .
Check CMP ignition feed circuit for short to ground or short to voltage. Repair as necessary. After repairs, go to step 35 . If circuit is okay, go to step 33 .
Turn ignition off. Disconnect PCM harness connector. Check continuity of CMP ground circuit. If continuity exists or resistance is 0-5 ohms, go to step 33 . If continuity does not exist or resistance is not 0-5 ohms, go to step 29 .
Turn ignition off. Disconnect PCM harness connector. Check continuity of CMP signal circuit. If continuity exists or resistance is 0-5 ohms, go to next step. If continuity does not exist or resistance is not 0-5 ohms, go to step 30 .
Check CMP signal circuit for short to ground or short to voltage. Repair as necessary. After repairs, go to step 35 . If circuit is okay, go to step 33 .
Check for proper connection at CMP sensor connector and jumper connector. Repair as necessary. After repairs, go to step 35 . If connections are okay, go to next step.
Repair CMP ignition feed circuit for an open or short to ground. After repairs, go to step 35 .
Check for proper connection at CMP sensor connector and jumper connector. Repair as necessary. After repairs, go to step 35 . If connections are okay, go to next step.
Repair open in CMP ground circuit. After repairs, go to step 35 .
Check for proper connection at CMP sensor connector and jumper connector. Repair as necessary. After repairs, go to step 35 . If connections are okay, go to next step.
Repair open in CMP signal circuit. After repairs, go to step 35 .
Repair short to voltage in CMP signal circuit. After repairs, go to step 35 .
Repair short to ground in CMP signal circuit. After repairs, go to step 35 .
Repair short to ground in CMP ignition feed circuit. After repairs, go to step 35 .
Check CMP ignition feed circuit for an open circuit. Repair as necessary. After repairs, go to step 35 . If circuit is okay, go to step 33 .
Repair open in CMP ground circuit. After repairs, go to step 35 .
Repair open in CMP signal circuit. After repairs, go to step 35 .
Check for proper connection at CMP harness connector. Repair as necessary. After repairs, go to step 35 . If connection is okay, go to next step.
Replace CMP sensor. After replacing sensor, go to step 35 .
Check for proper connection at PCM harness connector. Repair as necessary. After repairs, go to step 35 . If connection is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0342. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0342: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT-LOW VOLTAGE (5.7L "Y" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

System voltage is 9-17 volts.
Engine speed is less than 4000 RPM.
PCM detects CMP signal is stuck low for 1.5 seconds when signal should be high.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, select CAM SIGNAL INPUT and monitor HIGH/LOW TRANSITION counter. If counter is incrementing, go to next step. If counter is not incrementing, go to step 4 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter DTC P0342. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect PCM harness connector. Connect a DVOM to ground. Using Brown wire from Connector Kit (J-35616-A), connect DVOM (set to duty cycle) to CMP sensor signal circuit at PCM connector (harness side). Crank engine. If duty cycle is 45-55 percent, go to step 16 . If duty cycle is not as specified, go to next step.
Turn ignition off. Reconnect PCM harness connector. Remove intake manifold. Disconnect CMP sensor connector. Turn ignition on. Using DVOM, check voltage between battery ground and CMP sensor connector B+ reference circuit. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 8 .
Using DVOM, check voltage between CMP sensor connector B+ reference and ground circuits. If DVOM reads battery voltage, go to step 9 . If DVOM does not read battery voltage, go to next step.
Check for open in CMP sensor connector ground circuit. Repair circuit as necessary. After repairs, go to step 20 . If circuit is okay, go to step 16 .
Check for open or short to ground in CMP sensor connector B+ reference circuit. Repair circuit as necessary. After repairs, go to step 20 . If circuit is okay, go to step 16 .
Turn ignition on. Using DVOM, check voltage between ground CMP sensor connector signal circuit. If voltage reading is less than one volt, go to next step. If voltage reading is not as specified, go to step 13 .
Check voltage between battery positive and CMP sensor connector signal circuit. If voltage reading is less than one volt, go to next step. If voltage reading is not as specified, go to step 14 .
Turn ignition off. Disconnect PCM harness connector. Using DVOM, check resistance between CMP sensor signal circuit between CMP sensor connector and PCM. If resistance is less than 5 ohms, go to step 16 . If resistance is not less than 5 ohms, go to step 15 .
Repair open or short to ground in CMP sensor B+ reference circuit. After repairs, go to step 20 .
Repair open CMP sensor ground circuit. After repairs, go to step 20 .
Repair short to voltage in CMP sensor signal circuit. After repairs, go to step 20 .
Repair short to ground in CMP sensor signal circuit. After repairs, go to step 20 .
Repair open CMP sensor signal circuit. After repairs, go to step 20 .
Check connections at PCM. Repair as necessary. After repairs, go to step 20 . If connections are okay, go to next step.
Replace CMP sensor. After replacing sensor, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0342. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0343: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT-HIGH VOLTAGE (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

DTC will set when PCM detects that CMP signal is stuck high when signal should be low for 1.5 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, select CAM SIGNAL INPUT and monitor HIGH/LOW TRANSITION counter. If counter is incrementing, go to next step. If counter is not incrementing, go to step 4 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter this DTC. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect CMP sensor harness connector. Turn ignition on, with engine off. Using DVOM, measure voltage between ground and CMP sensor ignition feed circuit. If battery voltage is present, go to next step. If battery voltage is not present, go to step 7 .
Check voltage between CMP sensor ignition feed and ground circuit at harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 9 .
Start engine. Connect a test light to battery voltage. Using scan tool in ENGINE DATA LIST 1 function, monitor CAM signal input high-to-low and low-to-high transition counter while momentarily and repeatedly probing test light to sensor signal circuit. If transition counters increment when test light makes contact, go to step 15 . If transition counters does not increment when test light makes contact, go to step 10 .
Turn ignition off. Disconnect PCM harness connector. Using a DVOM, check continuity and resistance in ignition feed circuit. If continuity exists and resistance is 0-5 ohms, go to next step. If continuity does not exist and resistance is not 0-5 ohms, go to step 12 .
Check for poor connection or grounded circuit at CMP sensor ignition feed circuit. Repair as necessary. After repairs, go to step 19 . If circuit is okay, go to step 16 .
Turn ignition off. Disconnect PCM harness connector C1. Using DVOM, check continuity and resistance of CMP sensor ground circuit. If continuity exists and resistance is 0-5 ohms, go to step 16 . If continuity does not exists and resistance is not 0-5 ohms, go to step 13 .
Turn ignition off. Disconnect PCM harness connector C1. Using DVOM, check continuity and resistance of CMP sensor signal circuit. If continuity exists and resistance is 0-5 ohms, go to next step. If continuity does not exist and resistance is not 0-5 ohms, go to step 14 .
Turn ignition on, with engine off. Check for grounded or shorted to voltage in CMP signal circuit. Repair as necessary. After repairs, go to step 19 . If circuit is okay, go to step 16 .
Check for open in CMP sensor ignition feed circuit. Repair as necessary. After repairs, go to step 19 . If circuit is okay, go to step 16 .
Repair open in CMP sensor ground circuit. After repairs, go to step 19 .
Repair open in CMP sensor signal circuit. After repairs, go to step 19 .
Check for poor connections at CMP harness connector. Repair as necessary. After repairs, go to step 19 . If connections are okay, go to step 17 .
Check for poor connections at PCM harness connector. Repair as necessary. After repairs, go to step 19 . If connections are okay, go to step 18 .
Replace CMP sensor. After replacing sensor, go to step 19 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0343: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT-HIGH VOLTAGE (5.7L "F" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Ignition voltage is 5-17 volts.
Engine speed is less than 4000 RPM.
PCM detects CMP signal is stuck high when signal should be low for 5 seconds.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, monitor CAM signal input High-To-Low and Low-To-High transition parameter in ENGINE DATA LIST 1. If scan tool parameter increments, go to next step. If scan tool parameter does not increment, go to step 4 .
Turn ignition on, engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data for this DTC and observe parameters. Turn ignition off for 15 seconds. Start and operate engine at idle. Operate vehicle within conditions required for this DTC to set. Select DTC option, SPECIFIC DTC option and enter DTC P0342. If scan tool indicates that this DTC failed this ignition, go to next step. If scan tool does not indicate that this DTC failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect CMP jumper harness connector located near EGR valve. Turn ignition on, engine off. Using Brown terminal from Terminal Kit (J-35616-A), install terminal into CMP sensor ignition feed circuit on PCM harness side. Using DVOM, check voltage between CMP sensor ignition feed circuit and battery ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 14 .
Check voltage between CMP sensor ignition feed circuit and CMP sensor ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 16 .
Start engine. Using scan tool in ENGINE DATA LIST 1, monitor CAM signal input High-To-Low and Low-To-High transition. Momentarily and repeatedly probe signal circuit using a fused wire jumper connected to battery voltage. If CAM signal input increments when jumper contacts signal circuit, go to next step. If CAM signal input does not increment, go to step 17 .
At the CMP jumper harness, jumper ignition feed and ground circuit between PCM side of harness to CMP sensor side of harness. Connect a third jumper to signal circuit of CMP sensor side of harness. Start and operate engine at idle. Set DVOM to DC scale and duty cycle position. Connect DVOM between ground and CMP sensor signal circuit. If DVOM reads 45-55 percent, go to next step. If DVOM does not read 45-55 percent, go to step 9 .
Check PCM to CMP sensor jumper harness for proper connection. Repair as necessary. After repairs, go to step 35 . If connection is okay, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Remove intake manifold. Disconnect and then reconnect CMP sensor harness connector. Turn ignition on, engine off. Check voltage between CMP sensor ignition feed circuit and battery ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 19 .
Check voltage between CMP sensor ignition feed circuit and sensor ground. If DVOM reads battery voltage, go to next step. If DVOM does not read battery voltage, go to step 21 .
Disconnect CMP sensor jumper harness connector. Check continuity of CMP signal circuit. If continuity is present or resistance is 0-5 ohms, go to next step. If continuity is not present or resistance is not 0-5 ohms, go to step 23 .
Check voltage between ground and CMP signal circuit. If voltage reading is less than 1.0 volt, go to next step. If voltage reading is not less than 1.0 volt, go to step 25 .
Using a test light connected to battery voltage, probe CMP signal circuit. If test light illuminates, go to step 26 . If test light does not illuminate, go to step 31 .
Turn ignition off. Disconnect PCM harness connector. Check continuity of CMP ignition feed circuit. If continuity is present or resistance is 0-5 ohms, go to next step. If continuity is not present or resistance is not 0-5 ohms, go to step 28 .
Check CMP ignition feed circuit for short to ground or short to voltage. Repair as necessary. After repairs, go to step 35 . If circuit is okay, go to step 33 .
Turn ignition off. Disconnect PCM harness connector. Check continuity of CMP ground circuit. If continuity is present or resistance is 0-5 ohms, go to step 33 . If continuity is not present or resistance is not 0-5 ohms, go to step 29 .
Turn ignition off. Disconnect PCM harness connector. Check continuity of CMP signal circuit. If continuity is present or resistance is 0-5 ohms, go to next step. If continuity is not present or resistance is not 0-5 ohms, go to step 30 .
Check CMP signal circuit for short to ground or short to voltage. Repair as necessary. After repairs, go to step 35 . If circuit is okay, go to step 33 .
Check for proper connection at CMP sensor connector and jumper connector. Repair as necessary. After repairs, go to step 35 . If connections are okay, go to next step.
Repair CMP ignition feed circuit for an open or short to ground. After repairs, go to step 35 .
Check for proper connection at CMP sensor connector and jumper connector. Repair as necessary. After repairs, go to step 35 . If connections are okay, go to next step.
Repair open in CMP ground circuit. After repairs, go to step 35 .
Check for proper connection at CMP sensor connector and jumper connector. Repair as necessary. After repairs, go to step 35 . If connections are okay, go to next step.
Repair open in CMP signal circuit. After repairs, go to step 35 .
Repair short to voltage in CMP signal circuit. After repairs, go to step 35 .
Repair short to ground in CMP signal circuit. After repairs, go to step 35 .
Repair short to ground in CMP ignition feed circuit. After repairs, go to step 35 .
Check CMP ignition feed circuit for an open circuit. Repair as necessary. After repairs, go to step 35 . If circuit is okay, go to step 33 .
Repair open in CMP ground circuit. After repairs, go to step 35 .
Repair open in CMP signal circuit. After repairs, go to step 35 .
Check for proper connection at CMP harness connector. Repair as necessary. After repairs, go to step 35 . If connection is okay, go to next step.
Replace CMP sensor. After replacing sensor, go to step 35 .
Check for proper connection at PCM harness connector. Repair as necessary. After repairs, go to step 35 . If connection is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0342. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0343: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT-HIGH VOLTAGE (5.7L "Y" BODY)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

Camshaft Position (CMP) sensor is mounted on top of engine block, at rear of valley cover. CMP works in conjunction with CMP reluctor (1X signal). Reluctor is located on inside of engine, immediately in front of rear cam bearing. CMP sensor is used to determine whether a cylinder is on a firing or exhaust stroke. As camshaft rotates, reluctor wheel interrupts a magnetic field produced by magnet inside sensor. Sensor produces signal to PCM. PCM uses 1X signal along with CKP sensor 24X signal to determine crankshaft position and stroke. A slightly longer cranking time may be a symptom of this DTC. Conditions for setting DTC

System voltage is 9-17 volts.
Engine speed is less than 4000 RPM.
PCM detects CMP signal is stuck high for 1.5 seconds when signal should be low.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, select CAM SIGNAL INPUT and monitor HIGH/LOW TRANSITION counter. If counter is incrementing, go to next step. If counter is not incrementing, go to step 4 .
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter DTC P0343. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect PCM harness connector. Connect a DVOM to ground. Using Brown wire from Connector Kit (J-35616-A), connect DVOM (set to duty cycle) to CMP sensor signal circuit at PCM connector (harness side). Crank engine. If duty cycle is 45-55 percent, go to step 17 . If duty cycle is not as specified, go to next step.
Turn ignition off. Reconnect PCM harness connector. Remove intake manifold. Disconnect CMP sensor connector. Turn ignition on. Using DVOM, check voltage between battery ground and CMP sensor connector B+ reference circuit. If battery voltage is present, go to next step. If battery voltage is not present, go to step 8 .
Using DVOM, check voltage between CMP sensor connector B+ reference and ground circuits. If voltage reading is 13-16 volts, go to step 9 . If voltage reading is not as specified, go to next step.
Check for open in CMP sensor connector ground circuit. Repair circuit as necessary. After repairs, go to step 21 . If circuit is okay, go to step 17 .
Check for open or short to ground in CMP sensor connector B+ reference circuit. Repair circuit as necessary. After repairs, go to step 20 . If circuit is okay, go to step 17 .
Turn ignition on. Using DVOM, check voltage between ground CMP sensor connector signal circuit. If voltage reading is less than 1.0 volt, go to next step. If voltage reading is not less than 1.0 volt, go to step 14 .
Check voltage between battery positive and CMP sensor connector signal circuit. If voltage reading is less than 1.0 volt, go to next step. If voltage reading is not less than 1.0 volt, go to step 15 .
Turn ignition off. Disconnect PCM harness connector. Using DVOM, check resistance between CMP sensor signal circuit between CMP sensor connector and PCM. If resistance is less than 5 ohms, go to step 17 . If resistance is not as specified, go to step 16 .
Repair open or short to ground in CMP sensor B+ reference circuit. After repairs, go to step 20 .
Repair open CMP sensor ground circuit. After repairs, go to step 20 .
Repair short to voltage in CMP sensor signal circuit. After repairs, go to step 20 .
Repair short to ground in CMP sensor signal circuit. After repairs, go to step 20 .
Repair open CMP sensor signal circuit. After repairs, go to step 20 .
Check connections at PCM. Repair as necessary. After repairs, go to step 20 . If connections are okay, go to next step.
Replace CMP sensor. After replacing sensor, go to step 20 .
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0343. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

DTC P0351 &/OR P1351: IC CIRCUITS NO. 1 & 4 MALFUNCTION OR SHORTED (1.9L SATURN)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

PCM control dwell and spark timing during all engine running conditions. The Electronic Ignition (EI) module charges the coil pack when the PCM supplies 5 volts to the 1/4 coil. The coil will then discharge or fire through its secondary coil towers whenever the voltage has been turned off by the PCM.

During long cranking, PCM pulses the Ignition Control (IC) circuit high and low. The PCM monitors the diagnostic feedback circuit to diagnose circuit faults. DTC P0351 will set if there is an open, short to voltage or short to ground in IC 1 and 4 circuits or DTC P0351 or P1351 will set if there is a short to voltage in IC 1 and 4 circuits when engine is in cranking mode. IC circuits No. 1 and No. 4 are checked continuously whenever crankshaft position sensor pulses are received by the PCM during cranking mode only.

Connect scan tool. Start engine and check if DTC P0351 or P1351 is set. If DTCs are present, go to next step. If DTCs are not present, problem is intermittent. See «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
If only DTC P0351 is present, go to next step. If both DTCs P0351 and P1351 are present, turn ignition off. Disconnect EI module harness connector. Attempt to start engine. If only DTC P0351 resets, replace EI module. If DTCs P0351 and P1351 resets, check for short to voltage in IC 1/4 diagnostic feedback circuit or faulty PCM.
Turn ignition off. Disconnect EI module harness connector. Using DVOM connected to ground, probe IC 1/4 diagnostic feedback circuit while cranking engine. If voltage is varying between 0-5 volts, check terminal tightness to EI module or for faulty EI module. If voltage is not varying, go to next step.
Check IC 1/4 circuit for open or short to ground. Repair as necessary. If circuit is okay, check for tightness at EI module harness connector.

When attempting to diagnose an intermittent problem, use scan tool to review malfunction history information. This data can be used to duplicate a problem.

A malfunctioning 1/4 coil, 1/4 ignition wire or 1/4 spark plug will not cause DTC P0351 and/or P1351 to set. A blown EIS fuse will cause a no-start condition but an IC 1/4 DTC may not set. An IC 1/4 circuit fault may set a cam missing DTC P0340. If engine starts with a fault on the IC circuit, a misfire DTC P0300 may also be set. If there is an open in the IC 1/4 circuit a misfire on those cylinders will occur.

DTC P0351: IGNITION COIL NO. 1 CONTROL CIRCUIT (4.8L, 5.3L, 6.0L "C" & "K" SERIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

This engine uses an individual ignition coil/module and circuit for each cylinder. Sequencing and timing are controlled by PCM. DTC will set if PCM detects ignition control circuit is grounded, open or shorted to voltage within one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, select MISFIRE DATA LIST and monitor IC NO. 1 status. If scan tool displays DTC P0351, go to step 4 . If scan tool does not display this DTC, go to next step.
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter this DTC. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect ignition coil No. 1 connector. Using a DVOM in AC Hertz (Hz) scale, check frequency of IC No. 1 signal circuit. Start and operate engine at idle. If frequency is 3-20 Hz, go to step 8 . If frequency is not as specified, go to next step.
Using DVOM, check voltage on IC No. 1 signal circuit. If voltage reading is greater than 1.0 volt, go to step 9 . If voltage reading is not greater than 1.0 volt, go to next step.
Turn ignition off. Disconnect PCM harness connector. Using DVOM, check continuity of IC signal circuit from ignition coil No. 1 connector to PCM connector. If continuity exists, go to next step. If continuity does not exist, go to step 10 .
Using DVOM, check resistance of IC signal between ground and ignition coil No. 1 connector. If resistance is infinite, go to step 11 . If resistance is not infinite, go to step 10 .
Replace ignition coil. After replacing ignition coil, go to step 13 .
Repair IC signal circuit for short to voltage. After repairs, go to step 13 .
Repair IC signal circuit for open or short to ground. After repairs, go to step 13 .
Check for poor connections/terminal tension at PCM connector. Repair as necessary. After repairs, go to step 13 . If connection or terminal tension is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for poor connections/terminal tension at ignition coil and PCM. Check for rubbed-through wire insulation, broken wire inside insulation or misrouted harness.

DTC P0351: IGNITION COIL NO. 1 CONTROL CIRCUIT (5.7L "F" & "Y" BODIES)

Note. For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.

This engine uses an individual ignition coil/module and circuit for each cylinder. Sequencing and timing are controlled by PCM. DTC will set if IC circuit is out of range. DTC will set when the following conditions are present

System voltage is 9-17 volts.
PCM detects IC circuit is open or shorted to ground or voltage.
Conditions met for less than one second.

Perform On-Board Diagnostic (OBD) system check. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
Start and operate engine at idle. Using scan tool, select MISFIRE DATA LIST and monitor IC NO. 1 status. If scan tool displays DTC P0351, go to step 4 . If scan tool does not display this DTC, go to next step.
Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter DTC P0351. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see «DIAGNOSTIC AIDS»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-control-system-tests-wcodes-dtc-p0205-p0351) .
Turn ignition off. Disconnect ignition coil No. 1 connector. Using a DVOM in AC Hertz (Hz) scale, check frequency of IC No. 1 signal circuit. Start and operate engine at idle. If frequency is 3-20 Hz, go to step 8 . If frequency is not as specified, go to next step.
Using DVOM, check voltage on IC No. 1 signal circuit. If voltage reading is greater than 1.0 volt, go to step 9 . If voltage reading is not greater than 1.0 volt, go to next step.
Turn ignition off. Disconnect PCM harness connector. Using DVOM, check continuity of IC signal circuit from ignition coil No. 1 connector to PCM connector. If continuity exists, go to next step. If continuity does not exist, go to step 10 .
Using DVOM, check resistance of IC signal between ground and ignition coil No. 1 connector. If resistance is infinite, go to step 11 . If resistance is not infinite, go to step 10 .
Replace ignition coil. After replacing ignition coil, go to step 13 .
Repair IC signal circuit for short to voltage. After repairs, go to step 13 .
Repair IC signal circuit for open or short to ground. After repairs, go to step 13 .
Check for poor connections/terminal tension at PCM connector. Repair as necessary. After repairs, go to step 13 . If connection or terminal tension is okay, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0351. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2 .
Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.

Check for poor connections/terminal tension at ignition coil and PCM. Check for rubbed-through wire insulation, broken wire inside insulation or misrouted harness.

See also:
• DIAGNOSTIC AIDS
• DIAGNOSTIC AIDS

Engine Control System - Tests W/codes - DTC p0205-p0351 GMC Savana I

MODEL IDENTIFICATION

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.0L "V" BODY)

Circuit Description

Diagnostic Procedures

Diagnostic Aids

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.5L "W" BODY)

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

DTC P0205: INJECTOR NO. 5 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.0L "V" BODY)

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.5L "W" BODY)

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

DTC P0206: INJECTOR NO. 6 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0207: INJECTOR NO. 7 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0208: INJECTOR NO. 8 CONTROL CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.0L "V" BODY)

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.5L "W" BODY)

DTC P0230: FUEL PUMP CONTROL CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

DTC P0230: FUEL PUMP CONTROL CIRCUIT (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

DTC P0230: FUEL PUMP CONTROL CIRCUIT (5.7L "F" & "Y" BODIES)

DTC P0231: FUEL PUMP FEEDBACK CIRCUIT-LOW VOLTAGE (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0232: FUEL PUMP FEEDBACK CIRCUIT-HIGH VOLTAGE (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0243: SUPERCHARGER BOOST SOLENOID CONTROL CIRCUIT (3.8L "C", "G" & "W" BODIES - VIN 1)

DTC P0300: RANDOM CYLINDER MISFIRE DETECTED (1.9L SATURN)

DTC P0300: ENGINE MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

DTC P0300: ENGINE MISFIRE DETECTED (2.4L "J" & "N" BODIES)

DTC P0300: ENGINE MISFIRE DETECTED (3.0L "V" BODY)

DTC P0300: ENGINE MISFIRE DETECTED (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

DTC P0300: ENGINE MISFIRE DETECTED (3.8L "C", "F", "G", "H" & "W" BODIES)

DTC P0300: ENGINE MISFIRE DETECTED (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0300: MISFIRE DETECTED (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

DTC P0300: ENGINE MISFIRE DETECTED (4.3L "L", "M", "S" & "T" SERIES)

DTC P0300: ENGINE MISFIRE DETECTED (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

DTC P0300: ENGINE MISFIRE DETECTED (5.7L "F" BODY)

DTC P0300: ENGINE MISFIRE DETECTED (5.7L "Y" BODY)

DTC P0301, P0302, P0303 OR P0304: SPECIFIC CYLINDER MISFIRE DETECTED (1.9L SATURN)

DTC P0301: CYLINDER NO. 1 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

DTC P0301: CYLINDER NO. 1 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

DTC P0301: CYLINDER NO. 1 MISFIRE DETECTED (3.0L "V" BODY)

DTC P0302: CYLINDER NO. 2 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

DTC P0302: CYLINDER NO. 2 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

DTC P0302: CYLINDER NO. 2 MISFIRE DETECTED (3.0L "V" BODY)

DTC P0303: CYLINDER NO. 3 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

DTC P0303: CYLINDER NO. 3 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

DTC P0303: CYLINDER NO. 3 MISFIRE DETECTED (3.0L "V" BODY)

DTC P0304: CYLINDER NO. 4 MISFIRE DETECTED (2.2L "J" BODY & "S" SERIES)

DTC P0304: CYLINDER NO. 4 MISFIRE DETECTED (2.4L "J" & "N" BODIES)

DTC P0304: CYLINDER NO. 4 MISFIRE DETECTED (3.0L "V" BODY)

DTC P0305: CYLINDER NO. 5 MISFIRE DETECTED (3.0L "V" BODY)

DTC P0306: CYLINDER NO. 6 MISFIRE DETECTED (3.0L "V" BODY)

DTC P0322: IGNITION CONTROL (IC) MODULE 4X REFERENCE CIRCUIT-NO FREQUENCY (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0325: KNOCK SENSOR CIRCUIT (2.2L "J" BODY & "S" SERIES & 2.4L "J" & "N" BODIES)

DTC P0325: KNOCK SENSOR CIRCUIT-BANK 1 (3.0L "V" BODY)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (3.5L "W" BODY)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (3.8L "C", "F", "G", "H" & "W" BODIES)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.3L "L", "M", "S" & "T" SERIES)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

DTC P0325: KNOCK SENSOR MODULE CIRCUIT (5.7L "F" & "Y" BODIES)

DTC P0326: KNOCK SENSOR CIRCUIT-EXCESSIVE KNOCK PRESENT (1.9L SATURN)

DTC P0326: KNOCK SENSOR CIRCUIT-EXCESSIVE SPARK RETARD (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0327: KNOCK SENSOR CIRCUIT MALFUNCTION (1.9L SATURN)

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (3.1L "N" & "W" BODIES & 3.4L "N" BODY & "U" SERIES)

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (3.5L "W" BODY)

DTC P0327: KNOCK SENSOR CIRCUIT-BANK 1 (3.8L "C", "F", "G", "H" & "W" BODIES)

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (4.0L "G" BODY & 4.6L "E" & "K" BODIES)

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (4.3L, 5.0L, 5.7L & 7.4L "C", "G", "K" & "P" SERIES)

DTC P0327: KNOCK SENSOR CIRCUIT-LOW VOLTAGE (4.3L "L", "M", "S" & "T" SERIES)

DTC P0327: KNOCK SENSOR CIRCUIT-FRONT (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

DTC P0327: KNOCK SENSOR CIRCUIT-FRONT (5.7L "F" & "Y" BODIES)

DTC P0330: KNOCK SENSOR CIRCUIT-BANK 2 (3.0L "V" BODY)

DTC P0332: KNOCK SENSOR CIRCUIT-BANK 2 (3.8L "C", "F", "G", "H" & "W" BODIES)

DTC P0332: KNOCK SENSOR CIRCUIT-REAR (4.8L, 5.3L & 6.0L "C" & "K" SERIES)

DTC P0332: KNOCK SENSOR CIRCUIT (5.7L "F" & "Y" BODIES)

DTC P0335: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT (2.2L "J" BODY & "S" SERIES & 2.4L "J" & "N" BODIES)