Engine Controls - Tests W/codes - 7.3L Diesel: Diagnosis Ford Econoline E350

DIAGNOSTIC FORMATS

QUICK TEST and CIRCUIT TESTS are diagnostic formats used to test and service the diesel EEC-V system. QUICK TEST allows technician to identify problems and retrieve Diagnostic Trouble Codes (DTCs). CIRCUIT TESTS check circuits, sensors and actuators.

Before starting any CIRCUIT TEST, follow all steps under QUICK TEST to find appropriate circuit test to perform. If vehicle passes QUICK TEST and no driveability symptoms or intermittent faults exist, EEC-V system is functioning properly at this time.

DIAGNOSTIC TROUBLE CODES (DTC)

During QUICK TEST, 3 types of DTCs are retrieved: KOEO, KOER and Continuous Memory DTCs. See QUICK TEST for self-test procedures. DTCs may be cleared from PCM memory after they have been recorded or repaired. See CLEARING CODES .

KOEO & KOER ON-DEMAND SELF-TEST Codes

Record DTCs in order received. These DTCs indicate current faults in system and should be serviced in order of appearance. Use DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART to identify correct CIRCUIT TEST to perform.

Note. If self-test will not activate or TOOL COMMUNICATION ERROR is received, go to CIRCUIT TEST AF.

Diagnostic Aids

After each service or repair procedure has been completed, repeat QUICK TEST to ensure all EEC-V systems work properly and diagnostic trouble codes are no longer present. To keep battery from going dead when performing QUICK TEST, disconnect glow plug relay. Relay is located on top, right side of engine. Ignore Code P0380 while glow plug relay is disconnected.

Generic Scan Tool

Ensure scan tool meets or exceeds OBD-II standard. Follow manufacturers instructions to hook up equipment and record diagnostic trouble codes.

New Generation STAR (NGS) Scan Tool

Turn ignition off. Ensure proper memory (EPROM) card is inserted into NGS scan tool. Connect service connectors of adapter cable to vehicle Data Link Connector (DLC) and NGS scan tool. (Scheme 278) Connect NGS scan tool power supply cable to power and go to KOEO ON-DEMAND SELF-TEST.

Scheme 278

Performing Self-Test

To perform self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select PCM - POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select KOEO ON-DEMAND SELF-TEST.
7. Turn ignition on.
8. Follow operating instructions from scan tool menu.
9. If any Injector Driver Module (IDM) module DTCs are present, note and clear DTCs. IDM stores both history and hard DTCs. To ensure IDM is a hard DTC, repeat ON-DEMAND SELF-TEST.
10. Record DTCs and perform appropriate circuit test. See «DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART»(ref-24260-S41713808952001010400000) . After test is completed, cycle ignition switch before performing other self-tests or driving vehicle.

To perform self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select PCM - POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select KOER ON-DEMAND SELF-TEST.
7. Start engine and allow to idle.
8. Follow operating instructions from scan tool menu.
9. Record DTCs and perform appropriate circuit test. See «DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART»(ref-24260-S41713808952001010400000) . After test is completed, cycle ignition switch before performing other self-tests or driving vehicle.

To perform self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select PCM - POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select RETRIEVE/CLEAR CONTINUOUS DTCs.
7. Turn ignition on.
8. Follow operating instructions from scan tool menu.
9. If any Injector Driver Module (IDM) module DTCs are present, note and clear DTCs. IDM stores both history and hard DTCs. To ensure IDM is a hard DTC, repeat «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) .
10. Record DTCs and perform appropriate circuit test. See «DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART»(ref-24260-S41713808952001010400000) . After test is completed, cycle ignition switch before performing other self-tests or driving vehicle.

To perform self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select PCM - POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select KOEO INJECTOR ELECTRICAL SELF-TEST.
7. Turn ignition on.
8. Follow operating instructions from scan tool menu.
9. If any Injector Driver Module (IDM) module DTCs are present, note and clear DTCs. IDM stores both history and hard DTCs. To ensure IDM is a hard DTC, repeat «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) .
10. Record DTCs and perform appropriate circuit test. See «DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART»(ref-24260-S41713808952001010400000) . After test is completed, cycle ignition switch before performing other self-tests or driving vehicle.

Note. If no DTCs are present and injector self-test aborts while trying to perform test, go to CIRCUIT TEST AB, step 29).

To perform self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select PCM - POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select KOER SWITCH SELF-TEST.
7. Start engine and allow it to idle.
8. Follow operating instructions from scan tool menu.
9. Record DTCs and perform appropriate circuit test. See «DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART»(ref-24260-S41713808952001010400000) . After test is completed, cycle ignition switch before performing other self-tests or driving vehicle.

Note. Speed control DTCs will be set during KOER SWITCH SELF-TEST if vehicle is not equipped with speed control. This is a normal condition. On vehicles without speed control, ignore DTCs P0565, P0566, P0567, P0568 and P0569.

To perform self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select PCM - POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select KOER CYLINDER CONTRIBUTION SELF-TEST.
7. Start engine and allow it to idle.
8. Follow operating instructions from scan tool menu.
9. Record DTCs and perform appropriate circuit test. See «DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART»(ref-24260-S41713808952001010400000) . After test is completed, cycle ignition switch before performing other self-tests or driving vehicle.

To perform self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Start engine and allow it to idle.
2. Select VEHICLE & ENGINE SELECTION menu.
3. Select NEW VEHICLE, YEAR & MODEL.
4. Select DIAGNOSTIC DATA LINK.
5. Select PCM - POWERTRAIN CONTROL MODULE.
6. Select DIAGNOSTIC TEST MODE.
7. Select KOER GLOW PLUG MONITOR SELF-TEST.
8. Follow operating instructions from scan tool menu.
9. Maintain system voltage until test is complete.
10. Record DTCs and perform appropriate circuit test. See «DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART»(ref-24260-S41713808952001010400000) .

To perform output state self-test, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select PCM - POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select KOEO OUTPUT STATE SELF-TEST.
7. Turn ignition on.
8. Follow operating instructions from scan tool menu.

To perform freeze frame data mode, turn ignition off. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Follow operating instructions from scan tool menu.
4. Select GENERIC OBD-II FUNCTIONS. Press CONT button if OBD-II monitors are not complete.
5. Turn ignition on.
6. Select FREEZE FRAME PID REQUEST.

DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART

DIAGNOSTIC TROUBLE CODE (DTC) REFERENCE CHART

CIRCUIT TEST A - VEHICLE BATTERY

Note. In following tests, circuit diagrams and illustrations are courtesy of Ford Motor Co.

Enter this CIRCUIT TEST only if directed here from QUICK TEST, another test or chart. This test is only intended to diagnose

1. Closed loop power relay.
2. Powertrain Control Module (PCM).
3. Battery positive voltage (B+).
4. Wiring harness circuits (SIG RTN, PWR GND, KAPWR and VPWR).

To prevent replacement of good components, be aware the following non-EEC related areas and components may be cause of problem

1. Battery cables.
2. Ignition switch.
3. Voltage regulator.
4. Ground straps.
5. Alternator.

Vehicle Battery Test Circuits. Scheme 279

1. 1) DTC P0560, P0562 Or P0563: Check Battery Voltage Turn ignition off. Measure voltage between battery terminals. If voltage is 9.5 volts or less, repair charging system as necessary. If voltage is more than 9.5 volts, go to step 12).
2. 2) Check For Battery Voltage Measure voltage between negative battery terminal and output terminal (Yellow wire) of fuse No. 9 at power distribution box. If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open circuit in Yellow wire.
3. 3) Check Fuse Remove and inspect fuse No. 9 at power distribution box. If fuse is okay, go to next step. If fuse is blown, locate and repair short to ground and replace fuse.
4. 4) Check Circuit No. 37 Turn ignition off. Remove PCM relay from power distribution box. Measure resistance between non-powered side of No. 9 fuse holder and Yellow wire at PCM relay connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in Yellow wire.
5. 5) Check Ignition Feed To Diode Remove diode from power distribution box. Turn ignition on. Measure voltage between negative battery terminal and ignition feed side of diode connector. If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open in Red/Light Green wire or replace defective ignition switch.
6. 6) Check Diode Turn ignition off. Using an ohmmeter, check diode continuity. Ensure continuity exists in one direction only. Replace diode as necessary. If diode is okay, go to step 13). NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 6) to step 8). No test procedures have been omitted.
7. 8) Check Ground Circuit Turn ignition off. Measure resistance between negative battery terminal and circuit No. 57 (Black wire) at PCM relay connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit in Black wire.
8. 9) Check Circuit No. 361 Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance of Red wire between PCM relay connector and test pins No. 71 and 97 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in Red wire between PCM relay and PCM connector.
9. 10) Check PWR GND Circuit Measure resistance between negative battery terminal and test pins No. 25, 51, 76, 77 and 103 at breakout box. If each reading is less than 5 ohms, go to step 14). NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 10) to step 12). No test procedures have been omitted.
10. 12) Check Voltage At PCM Relay Turn ignition off. Remove PCM relay from power distribution box. Measure voltage between negative battery terminal and circuit No. 37 (Yellow wire) at PCM relay connector. If battery voltage is present, go to step 5). If battery voltage is not present, locate and repair open circuit in Yellow wire between PCM relay and starter relay.
11. 13) Check Circuit No. 16 Turn ignition off. Measure resistance of Red/Light Green wire between non-powered side of diode connector and PCM relay connector. If resistance is less than 5 ohms, go to step 8). If resistance is 5 ohms or more, repair open circuit in Red/Light Green wire between diode and relay.
12. 14) Check PCM Relay Turn ignition on. Measure voltage between negative battery terminal and test pins No. 71 and 97 at breakout box. If battery voltage is present, replace PCM. If battery voltage is not present, replace PCM relay.

SIG RTN is a dedicated ground used by most EEC-V system sensors. VREF is a 5-volt reference voltage that is continuously output by PCM. This consistent voltage signal is used on all 3-wire sensors. This CIRCUIT TEST is only intended to diagnose the following components and circuits

1. Three-wire sensors.
2. Vehicle wiring harness circuits (SIG RTN and VREF).
3. Powertrain Control Module (PCM).

Identifying Reference Voltage Circuits. Scheme 280

1. 1) Check Vehicle Battery Power Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950) and connect PCM to breakout box. Turn ignition on. Measure voltage between test pins No. 55, 71 and 97 and test pins No. 25, 51, 76, 77 and 103 at breakout box. If all readings are more than 10.5 volts and within one volt of each other, go to next step. If any reading is 10.5 volts or less or not within one volt of each other, go to «CIRCUIT TEST A»(ref-24260-S17790910942001010400000) .
2. 2) Check VREF Voltage Measure voltage between test pins No. 90 and 91 at breakout box. If voltage is 4-6 volts, go to next step. If voltage is less than 4 volts, go to step 5). If voltage is more than 6 volts, go to step 4).
3. 3) Check VREF & SIG RTN Circuits Turn ignition off. Disconnect suspect sensor connector. Disconnect PCM from breakout box. Measure resistance between test pin No. 90 at breakout box and VREF circuit terminal at suspect sensor wiring harness connector. Also, measure resistance between test pin No. 91 at breakout box and SIG RTN circuit terminal at suspect sensor wiring harness connector. If both readings are less than 5 ohms, no problem is indicated at this time. Fault may be intermittent. If any reading is 5 ohms or more, locate and repair open in VREF or SIG RTN circuit. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check For Excess Voltage Disconnect PCM connector from breakout box. Disconnect scan tool. Turn ignition on. Measure voltage between ground and test pin No. 90 at breakout box. If voltage is less than 5 volts, replace PCM. Reconnect all components and repeat QUICK TEST. If voltage is 5 volts or more, locate and repair short to power. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 5) Check SIG RTN Circuit Turn ignition off. Measure resistance between test pin No. 91 and test pins No. 25, 51, 76 and 103 at breakout box. If all readings are less than 5 ohms, go to next step. If any reading is 5 ohms or more, replace PCM.
6. 6) Check For Shorted Accelerator Pedal (AP) Sensor Disconnect AP sensor connector. Sensor is located above accelerator pedal. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. Measure voltage between test pins No. 90 and 91 at breakout box. If voltage is less than 4 volts, leave sensor disconnected and go to next step. If voltage is 4 volts or more, replace AP sensor. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check For Shorted Camshaft Position (CMP) Sensor Disconnect CMP sensor connector. Sensor is located in front of engine. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. Measure voltage between test pins No. 90 and 91 at breakout box. If voltage is less than 4 volts, leave sensor disconnected and go to next step. If voltage is 4 volts or more, replace CMP sensor. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
8. 8) Check For Shorted Injection Control Pressure (ICP) Sensor Disconnect ICP sensor connector. Sensor is located on top left side of engine. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. Measure voltage between test pins No. 90 and 91 at breakout box. If voltage is less than 4 volts, leave sensor disconnected and go to next step. If voltage is 4 volts or more, replace ICP sensor. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
9. 9) Check Exhaust Backpressure (EPB) Sensor Disconnect EPB sensor connector. Sensor is located on top center of engine. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. Measure voltage between test pins No. 90 and 91 at breakout box. If voltage is less than 4 volts, leave sensor disconnected and go to next step. If voltage is 4 volts or more, replace EPB sensor. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
10. 10) Check For Shorted Manifold Absolute Pressure (MAP) Sensor Disconnect MAP sensor connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. Measure voltage between test pins No. 90 and 91 at breakout box. If voltage is less than 4 volts, leave sensor disconnected and go to next step. If voltage is 4 volts or more, replace MAP sensor. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
11. 11) Check For Shorted Barometric Pressure (BARO) Sensor Disconnect BARO sensor connector. Sensor is located behind left side of instrument panel. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. Measure voltage between test pins No. 90 and 91 at breakout box. If voltage is less than 4 volts, leave sensor disconnected and go to next step. If voltage is 4 volts or more, replace BARO sensor. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
12. 12) Check For Shorted VREF Circuit Disconnect PCM connector from breakout box. Ensure all 6 sensors are disconnected. Measure resistance between test pin No. 90 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Reconnect all components and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 10,000 ohms or less, locate and repair short to ground. Reconnect all components and repeat QUICK TEST.

This circuit test is intended to diagnose the following components and circuits

1. Intake Air Temperature (IAT) sensor.
2. Wiring harness circuits (IAT and SIG RTN).
3. Powertrain Control Module (PCM).

Intake Temperature Sensor Circuits & Connector Terminals. Scheme 281

1. 1) DTC P0113 This DTC indicates sensor signal voltage is more than self-test maximum. Check for following possible causes: Faulty sensor. Faulty harness connector. Faulty Powertrain Control Module (PCM). Ensure scan tool is connected to Data Link Connector (DLC). See «VEHICLE PREPARATION & EQUIPMENT HOOKUP»(ref-24260-S20186903922001010400000) under QUICK TEST. Turn ignition on. Using scan tool, access IAT V PID (voltage) from PID/DATA monitor menu. If voltage is 4.9 volts or more, go to next step. If voltage is less than 4.9 volts, go to step 8).
2. 2) Induce Opposite Failure Disconnect IAT sensor connector. Connect a jumper wire between negative battery terminal and terminal "B" (Gray/Yellow wire) at IAT sensor wiring harness connector. If reading is more than zero volts, go to step 4). If reading is zero volts, go to next step.
3. 3) Check SIG RTN Circuit Turn ignition off. Measure resistance between ground and terminal "A" (Gray/Red wire) at IAT sensor wiring harness connector. If resistance is less than 5 ohms, replace IAT sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat QUICK TEST.
4. 4) Check Sensor Signal Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between terminal "B" (Gray/Yellow wire) at IAT sensor wiring harness connector and test pin No. 39 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Gray/Yellow wire. Clear DTCs and repeat QUICK TEST.
5. 5) DTC P0112 This DTC indicates sensor signal is less than self-test minimum. Possible causes for this fault are: Circuit grounded in wiring harness. Faulty sensor. Faulty harness connector. Faulty Powertrain Control Module (PCM). Ensure scan tool is connected to Data Link Connector (DLC). See «VEHICLE PREPARATION & EQUIPMENT HOOKUP»(ref-24260-S20186903922001010400000) under QUICK TEST. Turn ignition on. Using scan tool, access IAT V PID (voltage) from PID/DATA monitor menu. If voltage is .13 volt or less, go to next step. If voltage is more than .13 volt, go to step 8).
6. 6) Induce Opposite Failure Observe scan tool and disconnect IAT sensor connector. If voltage is 4.59 volts or more, replace IAT sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage is less than 4.59 volts, go to next step.
7. 7) Check For Short To Ground Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 39 and test pins No. 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 10,000 ohms or less, locate and repair short to ground in Gray/Yellow wire. Clear DTCs and repeat QUICK TEST.
8. 8) Continuous Memory DTC P0112 Or P1113: Check Sensor These DTCs indicate possible intermittent fault. Possible causes for this fault are: Faulty sensor. Faulty sensor connector. Open or grounded circuit in harness. Faulty PCM. With scan tool connected, turn ignition on. Access IAT V PID (voltage) from PID/DATA monitor menu. While observing scan tool, tap on sensor to simulate road shock. Wiggle sensor connector. If no change in voltage occurs, go to next step. If any change in voltage occurs, isolate fault and repair as necessary.
9. 9) Check Wiring Harness While observing IAT V PID, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (voltage fluctuates), isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no fault is found, go to next step.
10. 10) Inspect PCM & Wiring Harness Connectors Turn ignition off. Disconnect PCM 104-pin connector and IAT connector. Inspect connectors for damaged pins, corrosion and loose wires. If connectors and terminals are damaged, repair as necessary and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If connectors and terminals are okay, fault cannot be duplicated at this time and testing is complete.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose the following

1. MAP sensor.
2. Wiring harness circuits (VREF, SIG RTN and MAP SIG).
3. Powertrain Control Module (PCM).

Identifying MAP Sensor Circuits & Connector Terminals. Scheme 282

1. 1) DTC P0236 DTC P0236 indicates faulty turbo boost sensor circuit performance. Possible causes for this fault are: Damaged MAP sensor hose. Faulty MAP sensor. Low turbo boost. Intake manifold or crossover leaks. Inspect MAP sensor hose for damage, misrouting or restriction. Replace hose as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If hose is okay, go to next step.
2. 2) MAP Sensor Frequency Check Disconnect MAP sensor connector. Connect MAP sensor tester between MAP sensor and MAP sensor wiring harness connector. Connect DVOM to MAP sensor. Set DVOM to frequency scale. Turn ignition on. If frequency is 90-115 Hz, leave MAP sensor tester connected and go to next step. If frequency is not 90-115 Hz, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
3. 3) MAP Sensor Pressure Check Disconnect MAP sensor vacuum hose. Using Pressure Adapter (014-00761), apply 10 psi to MAP sensor. If frequency is 135-155 Hz, go to next step. If frequency is not 135-155 Hz, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) MAP Sensor Performance Test Reconnect vacuum hose to MAP sensor. Disconnect MAP sensor vacuum hose from intake manifold. Install a pressure (boost) gauge to intake manifold. Road test vehicle and accelerate vehicle to achieve full boost. If boost is 12 psi or more, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If boost is less than 12 psi, inspect intake manifolds and crossover tubes for leaks. Check turbo condition. Repair as necessary.
5. 5) KOEO DTC P0237 DTC P0237 indicates low input to turbo boost sensor. Possible causes for this fault are: Faulty MAP sensor. Open or shorted wiring harness circuits. Faulty PCM. Turn ignition off. Disconnect MAP sensor connector. Connect MAP sensor tester between MAP sensor and MAP sensor wiring harness connector. Connect banana plugs of tester into DVOM. Turn ignition on and observe tester. If Green light is on, VREF and SIG RTN circuits are okay. Go to next step. If voltage reading is less than 4 volts and Red light is on or no light is on, go to step 11). If voltage reading is more than 6 volts and Red light is on, go to step 14).
6. 6) Check For Short To Ground In MAP Sensor Signal Circuit Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect MAP sensor connector. Measure resistance between test pin No. 88 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground in MAP sensor signal circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check For Short To Power In MAP Sensor Signal Circuit Turn ignition on. Measure resistance between test pin No. 88 and test pins No. 55, 71 and 97 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to power in MAP sensor signal circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
8. 8) Check For Shorted VREF-To-MAP Sensor Signal Circuit Turn ignition off. Measure resistance between test pins No. 90 and No. 88 at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, VREF is shorted to MAP sensor signal circuit. Repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
9. 9) Check MAP Sensor Signal Circuit Continuity Measure resistance between test pin No. 88 at breakout box and Light Green/Black wire at MAP sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Light Green/Black wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
10. 10) Check PCM Connect PCM to breakout box. Turn ignition on. Measure voltage between ground and Light Green/Black wire at MAP sensor wiring harness connector. If voltage is 4.5-5.5 volts, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage is not 4.5-5.5 volts, replace PCM. Clear DTCs and repeat QUICK TEST.
11. 11) Check VREF Circuit Voltage Disconnect MAP sensor tester from MAP sensor, leaving tester connected to MAP sensor vehicle wiring harness connector. Turn ignition on and observe tester. If Green light is on, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If Red light is on or no light is on, go to next step.
12. 12) Check VREF Circuit Continuity Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect MAP sensor connector. Measure resistance between Brown/White wire at MAP sensor wiring harness connector and test pin No. 90 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Brown/White wire between MAP sensor connector and PCM connector. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
13. 13) Check SIG RTN Circuit Continuity Measure resistance between test pin No. 88 at breakout box and Gray/Red wire at MAP sensor wiring harness connector. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open in Gray/Red wire. Clear DTCs and repeat QUICK TEST.
14. 14) Check For Short To Power Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pin No. 90 at breakout box. If voltage is less than .25 volt, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage is .25 volt or more, locate and repair short to power in VREF circuit. Clear DTCs and repeat QUICK TEST.
15. 15) KOEO DTC P0238 DTC P0238 indicates high input in turbo boost sensor circuit. Possible causes for this fault are: Faulty MAP sensor. Faulty PCM. Disconnect MAP sensor connector. Connect MAP sensor tester between MAP sensor and MAP sensor wiring harness connector. Connect banana plugs of tester into DVOM. Set DVOM to frequency scale. Turn ignition on. If frequency is more than 125 Hz, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If frequency is 125 Hz or less, replace PCM. Clear DTCs and repeat QUICK TEST.
16. 16) Continuous DTC P0237 Continuous DTC P0237 indicates low input to turbo boost sensor. DTC P0235 indicates MAP sensor signal is inactive. Possible causes for these faults are: Faulty MAP sensor. Open or shorted wiring harness circuits. Faulty PCM. Turn ignition off. Disconnect MAP sensor connector. Connect MAP sensor tester between MAP sensor and MAP sensor wiring harness connector. Connect banana plugs of tester into DVOM. Set DVOM to frequency scale. Turn ignition on. If frequency is 105-115 Hz, go to next step. If frequency is not 105-115 Hz, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
17. 17) Check MAP Sensor While observing DVOM frequency, tap on sensor to simulate road shock. Wiggle sensor connector. If no change in frequency occurs, go to next step. If any change in frequency occurs, locate and repair intermittent open in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
18. 18) MAP Sensor Pressure Check Disconnect MAP sensor vacuum hose. Using Pressure Adapter (014-00761), apply 10 psi to MAP sensor. While observing DVOM, tap on sensor to simulate road shock. Wiggle sensor connector. If no change in frequency occurs, go to next step. If any change in frequency occurs, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
19. 19) Check SIG RTN Circuit Remove MAP sensor tester. Leave MAP sensor disconnected. Connect DVOM between ground and Gray/Red wire at MAP sensor wiring harness connector. Set DVOM to ohms scale. While observing DVOM, wiggle and bend small sections of wiring harness starting at MAP sensor wiring harness connector and working toward PCM. If fault is indicated (resistance fluctuates), repair intermittent open circuit in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no fault is found, go to next step.
20. 20) Check VREF Circuit Turn ignition on. Connect DVOM between ground and Brown/White wire at MAP sensor wiring harness connector. Set DVOM to volt scale. While observing DVOM, wiggle and bend small sections of wiring harness starting at MAP sensor wiring harness connector and working toward PCM. If fault is indicated (voltage fluctuates), locate and repair intermittent open circuit in Brown/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no fault is found, go to next step.
21. 21) Check MAP Sensor Signal Circuit Continuity Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect MAP sensor connector. Measure resistance between Light Green/Black wire at MAP sensor wiring harness connector and test pin No. 88. Resistance should be less than 5 ohms. While observing DVOM, wiggle and bend small sections of wiring harness starting at MAP sensor wiring harness connector and working toward PCM. If resistance stays at less than 5 ohms, go to next step. If resistance does not stay at less than 5 ohms, locate and repair intermittent open circuit in Light Green/Black wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
22. 22) Check For Short To Ground Measure resistance between test pin No. 88 and test pins No. 25, 51, 76, 77 and 103 at breakout box. While observing DVOM, wiggle and bend small sections of wiring harness starting at MAP sensor wiring harness connector and working toward PCM. If all readings are more than 10,000 ohms, go to next step. If any reading is less than 10,000 ohms, locate and repair intermittent short to ground in Light Green/Black wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
23. 23) Check For Short To Power Turn ignition on. Measure voltage between ground and test pin No. 88 at breakout box. While observing DVOM, wiggle and bend small sections of wiring harness starting at MAP sensor wiring harness connector and working toward PCM. If voltage stays at zero volts, fault cannot be duplicated at this time and testing is complete. If voltage does not stay at zero volts, locate and repair intermittent short to power in Light Green/Black wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
24. 24) Continuous DTC P0238 Continuous DTC P0238 indicates high input to turbo boost sensor circuit. Possible causes for this fault are: Faulty MAP sensor. Open or shorted wiring harness circuits. Faulty PCM. Turn ignition off. Disconnect MAP sensor connector. Connect MAP sensor tester between MAP sensor and MAP sensor wiring harness connector. Connect banana plugs of tester into DVOM. Set DVOM to frequency scale. Turn ignition on. Observe DVOM and tap on MAP sensor to simulate road shock. If frequency reading changes to more than 125 Hz, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If frequency reading does not change to more than 125 Hz, go to next step.
25. 25) Check MAP Sensor Disconnect MAP sensor vacuum hose. Using Pressure Adapter (014-00761), apply 10 psi to MAP sensor. While observing DVOM, tap on sensor to simulate road shock. Wiggle sensor connector. If frequency reading changes to more than 300 Hz, replace MAP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If frequency reading does not change to more than 300 Hz, go to next step.
26. 26) Check MAP Sensor Wiring Harness Disconnect MAP sensor vacuum hose. Using Pressure Adapter (014-00761), apply 10 psi to MAP sensor. While observing DVOM, wiggle and bend small sections of wiring harness starting at MAP sensor wiring harness connector and working toward PCM. If frequency reading changes to more than 300 Hz, repair intermittent circuit failure in wiring harness between MAP sensor and PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If frequency reading does not change to more than 300 Hz, fault cannot be duplicated at this time and testing is complete.

CIRCUIT TEST E - ACCELERATOR PEDAL (AP) SENSOR

Note. AP sensor is not serviced separately. If AP sensor is defective, accelerator pedal assembly must be replaced.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose the following

1. AP sensor.
2. Wiring harness circuits (VREF, SIG RTN and AP).
3. Powertrain Control Module (PCM).

Accelerator Pedal Sensor Circuits & Connector Terminals. Scheme 283

1. 1) DTC P0123 DTC P0123 indicates AP sensor circuit high input. Possible causes for this fault are: Damaged accelerator pedal assembly. AP sensor not installed properly. Faulty AP sensor. Short to power in wiring harness. Faulty Powertrain Control Module (PCM). With scan tool connected, turn ignition on. Access AP PID (voltage) from PID/DATA monitor menu. While observing scan tool, slowly depress accelerator pedal. If voltage reading changes to more than 4.5 volts, go to next step. If voltage reading does not change to more than 4.5 volts, fault cannot be duplicated at this time. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
2. 2) Induce Opposite Failure Disconnect AP sensor connector. AP sensor is mounted above accelerator pedal. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. If voltage reading changes from more than 4.5 volts to zero volts when connector is disconnected, circuit is okay. Replace accelerator pedal assembly. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage reading does not change from more than 4.5 volts to zero volts when connector is disconnected, go to next step.
3. 3) Check AP Sensor Signal Wire Turn ignition on. Measure voltage between ground and AP signal circuit terminal (Gray/White wire) at AP sensor wiring harness connector. If voltage is more than 4.5 volts, go to next step. If voltage is 4.5 volts or less, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check For Short To Power Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pin No. 89 at breakout box. If voltage is present, locate and repair short to power in Gray/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage is not present, replace PCM. Clear DTCs and repeat QUICK TEST.
5. 5) DTC P0122 DTC P0122 indicates AP sensor circuit low input. Possible causes for this fault are: Damaged accelerator pedal assembly. AP sensor not installed properly. Faulty AP sensor. Grounded wiring harness. Faulty Powertrain Control Module (PCM). With scan tool connected, turn ignition on. Access AP PID (voltage) from PID/DATA monitor menu on scan tool. While observing scan tool, slowly depress accelerator pedal. If voltage reading changes to less than .37 volt, go to next step. If voltage reading does not change to less than .37 volt, fault cannot be duplicated at this time. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 6) Induce Opposite Failure Disconnect AP sensor connector. Connect a jumper wire between VREF circuit terminal (Brown/White wire) and AP sensor signal circuit terminal (Gray/White wire) at AP sensor wiring harness connector. If voltage reading changes from less than .37 volt to more than 4.5 volts with jumper connected, circuit is okay. Replace accelerator pedal assembly. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage reading does not change from less than .37 volt to more than 4.5 volts with jumper connected, go to next step.
7. 7) Check VREF Circuit Voltage Turn ignition on. Measure voltage between ground and VREF circuit terminal (Brown/White wire) at AP sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, locate and repair open in VREF circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
8. 8) Check SIG RTN Circuit Turn ignition off. Measure resistance between ground and SIG RTN circuit terminal (Gray/Red wire) at AP sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in SIG RTN circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
9. 9) Check AP Sensor Circuit Continuity Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between AP sensor signal circuit terminal (Gray/White wire) and test pin No. 89 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in AP signal circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
10. 10) Check For Short To Ground Turn ignition off. Ensure AP sensor is disconnected. Measure resistance between test pin No. 89 and test pins No. 51, 76, 77, 91 and 103 at breakout box. If each reading is more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground in AP sensor signal circuit (Gray/White wire). Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
11. 11) Check VREF Circuit Continuity Measure resistance between VREF circuit terminal (Brown/White wire) at AP sensor wiring harness connector and test pin No. 90 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in VREF circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
12. 12) Check SIG RTN Circuit Continuity Measure resistance between SIG RTN circuit terminal (Gray/Red wire) at AP sensor wiring harness connector and test pin No. 24 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open in SIG RTN circuit. Clear DTCs and repeat QUICK TEST.

CIRCUIT TEST F - SPEED CONTROL COMMAND SWITCH (SCCS)

Perform this test when directed by QUICK TEST or by another circuit test. This CIRCUIT TEST is intended to diagnose the following

1. Speed control switches.
2. Wiring harness circuits (SCCS).
3. Powertrain Control Module (PCM).

Identifying SCCS Circuits & Connector Terminals. Scheme 284

When performing KOER SWITCH SELF-TEST, wait 5 seconds after pressing trigger to the test before running through driver operated controls. Test may take up to 5 minutes to complete.

1. 1) DTC P0565, P0566, P0567, P0568 Or P0569: Speed Control DTC P0565, P0566, P0567, P0568 or P0569 will set if PCM does not detect when a switch has been pressed during KOER SWITCH SELF-TEST. Possible causes for these faults are: Switch not depressed during test. Faulty speed control switch. Faulty SCCS circuit. Open or short in SC GND circuit. Open in power supply circuit. With scan tool connected, turn ignition on. Access SCCS PID from PID/DATA monitor menu on scan tool. Do not depress any switches. If SCCS PID voltage is 10 volts, go to step 5). If SCCS PID voltage is zero volts, go to step 8). If SCCS PID voltage is 6.58-6.78 volts, go to next step.
2. 2) Switch On Function Check Depress speed control On switch. If SCCS PID voltage is 10 volts, go to next step. If SCCS PID voltage is not 10 volts, go to step 20).
3. 3) Switch Off Function Check Depress speed control Off switch. If SCCS PID voltage is zero volts, go to next step. If SCCS PID voltage is not zero volts, go to step 26).
4. 4) Command Switches Function Depress speed control Resume, Coast and Set/Accel switches. Observe voltage reading on scan tool as each switch is depressed. If SCCS PID voltage reading agrees with voltage specification, repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If DTC is still present, replace PCM. See SPEED CONTROL COMMAND SWITCH PID SPECIFICATIONS table. If any SCCS PID voltage reading does not agree with voltage specification, replace speed control switch assembly. Clear DTCs and repeat KOER SWITCH SELF-TEST. SPEED CONTROL COMMAND SWITCH PID SPECIFICATIONS Switch Volts Coast .48-.88 Set/Accel 2.54-2.94 Resume 4.46-4.86
5. 5) Check For Shorted Command Switch Remove driver-side air bag module. See «AIR BAG RESTRAINT SYSTEM»(ref-24277) S article in the ACCESSORIES & EQUIPMENT section. Disconnect speed control switch 5-pin connector. If SCCS PID voltage reading is 6.58-6.78 volts, switch assembly is shorted. Replace speed control switch assembly. If SCCS PID voltage reading is not 6.58-6.78 volts, go to next step.
6. 6) Check Sliding Contact (Clockspring) Disconnect clockspring-to-steering column 6-pin connector. Connector is located below steering column. If SCCS PID voltage reading is 6.58-6.78 volts, clockspring is shorted to power. Replace clockspring. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If SCCS PID voltage reading is not 6.58-6.78 volts, go to next step.
7. 7) Signal Circuit Check Turn ignition off. Ensure steering column connector and speed control switch 5-pin connector are disconnected. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pin No. 61 at breakout box. If SCCS PID voltage reading is zero volts, replace PCM. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If SCCS PID voltage reading is not zero volts, locate and repair short to power in Light Blue/Black wire.
8. 8) Check For Shorted Command Switch Remove driver-side air bag module. See «AIR BAG RESTRAINT SYSTEM»(ref-24277) S article in the ACCESSORIES & EQUIPMENT section. Disconnect speed control switch 5-pin connector. If SCCS PID voltage is 6.58-6.78 volts, clockspring wiring harness in steering column is shorted to ground. Replace clockspring. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If SCCS PID voltage is not 6.58-6.78 volts, go to next step.
9. 9) Check Sliding Contact (Clockspring) Disconnect clockspring-to-steering column 6-pin connector. Connector is located below steering column. If SCCS PID voltage is 6.58-6.78 volts, clockspring and wiring harness in steering column are shorted to ground. Replace clockspring. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If SCCS PID voltage is not 6.58-6.78 volts, go to next step.
10. 10) Signal Circuit Check Turn ignition off. Ensure clockspring-to-steering column connector is disconnected. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 61 and test pins No. 25, 51, 76, 77 and 103 at breakout box. If each reading is more than 10,000 ohms, replace PCM. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If any reading is 10,000 ohms or less, locate and repair short to ground in Light Blue/Black wire. Clear DTCs and repeat KOER SWITCH SELF-TEST. NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 10) to step 12). No test procedures have been omitted.
11. 12) Check Circuit Continuity Remove horn pad. Disconnect 3-pin speed control switch connector. Remove No. 3 fuse from power distribution box. Measure resistance between non-powered side of No. 3 fuse holder and terminal "C" (Dark Blue wire) at speed control switch 3-pin connector. If resistance is less than 75 ohms, go to step 14). If resistance is 75 ohms or more, go to next step.
12. 13) Check Clockspring Resistance Disconnect clockspring-to-steering column 10-pin Gray connector. Connector is located below steering column. Measure resistance of Dark Blue wire between terminal "C" at 3-pin speed control switch connector and terminal No. 6 at 10-pin Gray connector (steering column side of connector). If resistance is less than 5 ohms, locate and repair open circuit between fuse No. 3 and 10-pin connector or replace defective horn relay. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If resistance is 5 ohms or more, replace clockspring. Clear DTCs and repeat KOER SWITCH SELF-TEST.
13. 14) Check Speed Control Switch Depress speed control On switch. Measure resistance between terminals "C" (Dark Blue wire) and "B" (Light Blue/Black wire) at speed control switch 3-pin connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace speed control switch assembly. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) .
14. 15) Check Clockspring Ensure speed control switch 3-pin connector is disconnected. Measure resistance of Light Blue/Black wire between terminal "B" at 3-pin connector and terminal No. 5 at clockspring-to-steering column 10-pin Gray connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Light Blue/Black wire. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) .
15. 16) Check Circuit No. 151 Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect clockspring-to-steering column 10-pin Gray wiring harness connector. Connector is located below steering column. Measure resistance between test pin No. 61 at breakout box and terminal No. 5 (Light Blue/Black wire) at 10-pin wiring harness connector. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If resistance is 5 ohms or more, replace clockspring. Clear DTCs and repeat KOER SWITCH SELF-TEST.
16. 17) Check Switch Ground Remove horn pad. Turn ignition on. Disconnect speed control switch 3-pin connector. Measure voltage between terminals "A" and "C" at clockspring side of speed control switch 3-pin connector. If battery voltage is present, replace speed control switch assembly. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If battery voltage is not present, go to next step.
17. 18) Check For Open Clockspring Circuit Disconnect clockspring-to-steering column 10-pin Gray connector. Connector is located below steering column. Measure resistance of Dark Green/Orange wire between terminal "A" at speed control switch 3-pin connector and terminal No. 2 at clockspring-to-steering column 10-pin Gray connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace clockspring. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) .
18. 19) Check For Open Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Dark Green/Orange wire at terminal No. 2 of clockspring-to-steering column 10-pin Gray connector and test pin No. 40 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Dark Green/Orange wire. Clear DTCs and repeat KOER SWITCH SELF-TEST.
19. 20) Check Fuse Remove and inspect fuse No. 27 from power distribution box located in engine compartment. If fuse is blown, check for cause of blown fuse. Repair as necessary and replace fuse. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If fuse is okay, go to next step.
20. 21) Check Circuit Continuity Remove driver-side air bag module. See «AIR BAG RESTRAINT SYSTEM»(ref-24277) S article in the ACCESSORIES & EQUIPMENT section. Disconnect speed control switch 5-pin connector. Measure resistance of Yellow/Light Blue wire between non-powered side of fuse No. 27 holder and terminal "C" speed control switch 3-pin connector (clockspring side). If resistance is less than 75 ohms, go to next step. If resistance is 75 ohms or more, go to step 25).
21. 22) Check Speed Control Switch Depress speed control On switch. Measure resistance between terminals "A" (Light Blue/Black wire) and "C" (Dark Blue wire) at speed control switch 5-pin connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace speed control switch assembly. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) .
22. 23) Check For Open Circuit Turn ignition off. Disconnect clockspring-to-steering column 6-pin wiring harness connector. Connector is located below steering column. Measure resistance between terminal No. 6 (Light Blue/Black wire) at 10-pin wiring harness connector and test pin No. 61 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Light Blue/Black wire. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) .
23. 24) Check Clockspring Disconnect speed control switch 5-pin connector. Measure resistance of Light Blue/Black wire between terminal "C" at 5-pin connector and terminal No. 5 at clockspring-to-steering column 6-pin connector. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If resistance is 5 ohms or more, replace clockspring. Clear DTCs and repeat KOER SWITCH SELF-TEST.
24. 25) Check Clockspring Resistance Disconnect clockspring-to-steering column 6-pin connector. Measure resistance of Dark Blue wire between terminal "C" at 5-pin connector and terminal No. 5 at clockspring-to-steering column 6-pin connector (steering column side). If resistance is less than 5 ohms, locate and repair open circuit between fuse No. 27 and clockspring-to-steering column 6-pin wiring harness connector or replace faulty horn relay. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If resistance is 5 ohms or more, replace clockspring. Clear DTCs and repeat KOER SWITCH SELF-TEST.
25. 26) Check Switch Ground Remove driver-side air bag module. See «AIR BAG RESTRAINT SYSTEM»(ref-24277) S article in the ACCESSORIES & EQUIPMENT section. Disconnect speed control switch 5-pin connector. Turn ignition on. Measure voltage between terminals "B" and "C" at clockspring side of speed control switch 5-pin connector. If battery voltage is present, replace speed control switch assembly. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If battery voltage is not present, go to next step.
26. 27) Check For Open Clockspring Circuit Turn ignition off. Disconnect clockspring-to-steering column 6-pin connector. Connector is located below steering column. Measure resistance of Dark Green/Orange wire between terminal "B" at speed control switch 5-pin connector and terminal No. 3 at clockspring-to-steering column 6-pin Gray connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace clockspring. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) .
27. 28) Check For Open Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Dark Green/Orange wire at terminal No. 3 of clockspring-to-steering column 6-pin Gray connector and test pin No. 40 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Dark Green/Orange wire. Clear DTCs and repeat KOER SWITCH SELF-TEST.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. Camshaft Position (CMP) sensor.
2. Wiring harness circuits (CMP GND, VREF and CMP signal).
3. Powertrain Control Module (PCM).

Camshaft Position Sensor Circuit & Connector Terminals. Scheme 285

1. 1) DTC P0340, P0341 & P0344: Clear Memory & Attempt To Regenerate DTC Ensure scan tool is connected to Data Link Connector (DLC). See «VEHICLE PREPARATION & EQUIPMENT HOOKUP»(ref-24260-S20186903922001010400000) under QUICK TEST. Clear continuous DTCs. Using scan tool, access RPM PID from PID/DATA monitor menu. Crank engine while monitoring RPM PID. If PID indicates cranking RPM, go to next step. If PID does not indicate cranking RPM, go to step 3).
2. 2) Check For DTC P0344 Or P0341 Start and run engine until coolant is at normal operating temperature. Raise engine speed to 3300 RPM for 2 minutes. Turn ignition off. Check for DTCs. If DTC P0344 or P0341 is set, go to next step. If DTC P0344 or P0341 is not set, fault is intermittent. Go to step 12).
3. 3) Check CMP Signal Turn ignition off. Disconnect CMP sensor connector. Measure resistance between ground and terminal "A" (Light Blue wire) at CMP sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 9).
4. 4) Check CMP Circuit No. 351 Turn ignition on. Measure voltage between ground and terminal "B" (Brown/White wire) at CMP sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, VREF circuit is defective. Go to «CIRCUIT TEST B»(ref-24260-S18677802082001010400000) .
5. 5) Check CMP Circuit No. 795 Measure voltage between ground and terminal "C" (Dark Green wire) at CMP sensor wiring harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 7).
6. 6) Check For Short To Power Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. Measure voltage between ground and terminal "C" (Dark Green wire) at CMP sensor wiring harness connector. If battery voltage is present, locate and repair short to power in Dark Green wire. Confirm repair by repeating steps 1) and 2). If battery voltage is not present, replace CMP sensor.
7. 7) Check For Short To Ground Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Measure resistance between ground and terminal "C" (Dark Green wire) at CMP sensor wiring harness connector. If resistance is less than 5 ohms, locate and repair short to ground in Dark Green wire. Confirm repair by repeating steps 1) and 2). If resistance is 5 ohms or more, go to next step.
8. 8) Check For Open Circuit Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between terminal "C" (Dark Green wire) at CMP sensor wiring harness connector and test pin No. 21 at breakout box. If resistance is less than 5 ohms, an open circuit exists at test pin No. 21. Inspect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all components and go to step 11). If resistance is 5 ohms or more, locate and repair open circuit in Dark Green wire. Confirm repair by repeating steps 1) and 2).
9. 9) Check For Open In CMP Sensor Ground Circuit Turn ignition off. Ensure CMP sensor is disconnected. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Light Blue wire at CMP sensor wiring harness connector and test pin No. 65 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Light Blue wire. Confirm repair by repeating steps 1) and 2).
10. 10) Check For CMP Sensor Ground Through PCM Connect PCM to breakout box. Measure resistance between ground and test pins No. 25, 51, 76, 77 and 103. If all readings are less than 5 ohms, PCM internal ground is not supplied to terminal No. 65. Reconnect all components and go to next step. If any reading is 5 ohms or more, locate and repair open in ground circuit. Confirm repair by repeating steps 1) and 2).
11. 11) Confirm PCM Fault Repeat steps 1) and 2). If fault is still present, replace PCM. If fault is not present, no problem is indicated at this time. Testing is complete.
12. 12) Check For Intermittent Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950) and connect PCM. To prevent vehicle from starting, disconnect Injector Driver Module (IDM) relay. Relay is located in power distribution box in engine compartment. Connect DVOM between test pin No. 65 and test pin No. 21 at breakout box. Rotate crankshaft (by hand) until voltage toggles from battery voltage to .3-2.7 volts. If lower voltage reading is .3-2.7 volts, go to next step. If lower voltage reading is not .3-2.7 volts, go to step 3).
13. 13) Check Wiring Harness Rotate crankshaft (by hand) until voltage stays at .3-2.7 volts. While observing DVOM, wiggle wiring harness. If a fault occurs, voltage reading will jump to battery voltage or zero volts. If fault occurs, locate and repair intermittent in wiring harness. Confirm repair by repeating steps 1) and 2). If no fault occurs, no problem is indicated at this time. Repeat steps 1) and 2).

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. Exhaust Backpressure (EBP) sensor.
2. Wiring harness circuits (SIG RTN, VREF and EBP signal).
3. Powertrain Control Module (PCM).

Exhaust Backpressure Sensor Circuit & Connector Terminals. Scheme 286

Scheme 287

Scheme 288

1. 1) DTC P0470 This DTC indicates PCM detected EBP sensor malfunction during KOEO ON-DEMAND SELF-TEST. Possible causes for this DTC are: Faulty EBP sensor. Open or shorted circuit. Faulty PCM. Ensure scan tool is connected to Data Link Connector (DLC). See «VEHICLE PREPARATION & EQUIPMENT HOOKUP»(ref-24260-S20186903922001010400000) under QUICK TEST. Using scan tool, access EBP PID from PID/DATA monitor menu. If EBP reading is less than 18.5 psi, clear DTCs. Repeat «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000). If DTC is still present, replace PCM. If EBP reading is 18.5 psi or more, go to next step.
2. 2) Check Signal Ground Circuit Turn ignition off. Disconnect EBP sensor connector. Sensor is located on top of engine. Inspect for damaged pins, corrosion and loose wires. Repair as necessary. Measure resistance between ground and Gray/Red wire at EBP sensor wiring harness connector. If resistance is less than 5 ohms, replace EBP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat QUICK TEST.
3. 3) Continuous DTC P0470 This DTC indicates PCM detected an EBP sensor malfunction during normal driving conditions. Possible causes for this DTC are: Faulty EBP sensor. Faulty connection. Faulty PCM. Ensure scan tool is connected to Data Link Connector (DLC). See «VEHICLE PREPARATION & EQUIPMENT HOOKUP»(ref-24260-S20186903922001010400000) under QUICK TEST. Using scan tool, access EBP PID from PID/DATA monitor menu. While observing EBP PID, wiggle and bend small sections of wiring harness starting at EBP sensor connector and working toward PCM. If EBP reading fluctuates, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If reading does not fluctuate, go to next step.
4. 4) Check Connector Disconnect EBP sensor connector. Sensor is located on top of engine. Disconnect PCM 104-pin connector. Inspect connectors for damaged pins, corrosion and loose wires. Repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If both connectors are okay, no problem is indicted at this time, Clear DTCs and repeat QUICK TEST.
5. 5) DTC P0471 This DTC indicates PCM detected an EBP sensor malfunction during normal driving conditions, and with EBP sensor enabled. Possible causes for this DTC are: Faulty EBP sensor. Plugged or restricted sensor supply tube. Damaged Exhaust Pressure Regulator (EPR) linkage or butterfly damage. Faulty PCM. Perform «KOER ON-DEMAND SELF-TEST»(ref-24260-S27861546292001010400000). If any DTCs are present, repair fault(s) before continuing with this test. Using scan tool, access EBP PID from PID/DATA monitor menu. Road test vehicle performing hard accelerations while monitoring EBP PID. If EBP reading increases to more than 25 psi with EBP sensor on, no problem is indicated at this time. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If EBP reading does not increase to more than 25 psi, go to next step.
6. 6) Check For Exhaust Leaks Inspect turbo pipe, crossover pipes, and exhaust manifolds for leaks. Repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If no exhaust leaks are present, go to next step.
7. 7) Check Sensor Supply Tube Inspect EBP sensor supply tube from exhaust manifold to sensor bracket. Ensure tube is not restricted or plugged. Replace tube as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If tube is okay, go to next step.
8. 8) Check EBP Sensor Disconnect EBP sensor connector. Install ICP/EBP Adapter Cable (D94T-50-A) between EBP sensor and sensor wiring harness connector. Start engine. Measure voltage between signal circuit and signal ground at ICP/EBP adapter cable. Briefly accelerate engine to Wide Open Throttle (WOT) several times. If voltage reading during acceleration is more than 1.35 volts, clear DTCs and retest. If DTC is still present, replace PCM. If voltage reading during acceleration is not more than 1.35 volts, replace EBP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
9. 9) DTC P0472: EBP Circuit Low Input This DTC indicates EBP sensor circuit low input was detected during KOEO ON-DEMAND SELF-TEST or during continuous diagnostic monitoring. Possible causes for this DTC are: Biased sensor/PCM. Open or shorted EBP sensor circuit. EBP sensor circuit shorted. Faulty PCM. Turn ignition off. Disconnect EBP sensor connector. Sensor is located on top of engine. Turn ignition on. Measure voltage between ground and Brown/White wire at EBP sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, locate and repair open circuit in Brown/White wire (VREF circuit). Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
10. 10) Check SIG RTN Circuit Measure resistance between ground and Gray/Red wire at EBP sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
11. 11) Check EBP Signal Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Purple/Light Blue wire at EBP sensor wiring harness connector and test pin No. 30 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Purple/Light Blue wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
12. 12) Check VREF Circuit Measure resistance between Brown/White wire at EBP sensor wiring harness connector and test pin No. 90 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Brown/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
13. 13) Check For Grounded EBP Signal Circuit Measure resistance between test pin No. 30 and test pins No. 25, 51, 76, 77, 91 and 103. If all readings are more than 10,000 ohms, go to next step. If any reading is less than 10,000 ohms, locate and repair short to ground in EBP signal circuit (Purple/Light Blue wire). Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
14. 14) Check For Internal PCM Short Connect PCM connector to breakout box. Measure resistance between test pin No. 30 and test pins No. 25, 51, 76, 77, 91 and 103. If all readings are more than 10,000 ohms, replace EBP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If any reading is 10,000 ohms or less, replace PCM. Clear DTCs and repeat QUICK TEST.
15. 15) DTC P0473 This DTC indicates EBP sensor circuit high input was detected during KOEO ON-DEMAND SELF-TEST or during continuous diagnostic monitoring. Possible causes for this DTC are: Biased sensor/PCM. EBP sensor shorted to VREF circuit. Faulty PCM. Turn ignition on. Disconnect EBP sensor connector. Sensor is located on top of engine. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000). If DTC P0472 is present, replace EBP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If DTC P0472 is not present, go to next step.
16. 16) Check For Short To Power Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 30 and test pins No. 55, 71, 90 and 97 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If any reading is 10,000 ohms or less, locate and repair short to power in Purple/Light Blue wire. Clear DTCs and repeat QUICK TEST.
17. 17) DTC P0478 This DTC indicates excessive backpressure existed during normal driving. Possible causes for this DTC are: Stuck butterfly. Plugged EBP sensor tube. Restricted exhaust. Misadjusted Exhaust Pressure Regulator (EPR) linkage. Faulty PCM. Visually inspect exhaust backpressure control valve. If valve is in Open position, go to next step. (Scheme 287) If valve is not in Open position, repair damaged linkage or butterfly as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). (Scheme 287): Identifying Open Exhaust Backpressure Control Valve Position
18. 18) Check For Exhaust Restriction Using scan tool, access EBP PID from PID/DATA monitor menu. Start engine. Briefly accelerate engine speed to Wide Open Throttle (WOT) while monitoring EBP PID. If EBP PID reading is less than 28 psi, go to next step. If EBP PID reading is 28 psi or more, repair restricted exhaust system. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
19. 19) Check EBP System To begin this test, engine must be cold. To confirm engine is cold, ensure EOT PID reading is less than 70°F (21°C) and IAT PID reading is less than 45°F (7°C). Road test vehicle while monitoring EBP PID reading on scan tool. With EBP sensor on, if EBP reading stays at less than 50 psi, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). With EBP sensor on, if EBP reading does not stay at less than 50 psi, check and adjust turbocharger control rod as necessary. Spring scale reading should be 10 lbs. (4.5 kg) (Scheme 288) (Scheme 288): Adjusting Control Rod Tension

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. PSOM output to PCM.
2. PSOM (+) and PSOM (-) wiring harness circuits.
3. Powertrain Control Module (PCM).

To prevent replacement of good components, be aware following non-EEC related areas and components may be cause of problem

1. Cruise control system.
2. Rear anti-lock brake system.
3. Ring gear inside differential.
4. Instrumentation system.

Programmable Speedometer/Odometer Module (PSOM) Circuit Logic. Scheme 289

Identifying Programmable Speedometer/Odometer Module (PSOM) Circuit & Connector Terminals. Scheme 290

1. 1) DTC P0500 DTC P0500 indicates PCM detected incorrect output from Vehicle Speed Sensor (VSS) sometime during vehicle operation. Possible causes for this DTC are: PSOM output to PCM. PSOM (+) and PSOM (-) wiring harness circuits. Faulty PCM. Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pins No. 33 and 58 at breakout box. If resistance is 21,000-55,000 ohms, go to step 4). If resistance is not 21,000-55,000 ohms, go to next step.
2. 2) Check PSOM Circuit Continuity Ensure ignition is off. Disconnect PSOM wiring harness connector. PSOM is located behind left side of instrument panel. Measure resistance between test pin No. 58 at breakout box and PSOM (+) circuit (Gray/Black wire) at PSOM wiring harness connector. Also, measure resistance between test pin No. 33 at breakout box and PSOM (-) circuit (Pink/Orange wire) at PSOM wiring harness connector. If any reading is 5 ohms or more, locate and repair open circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If both readings are less than 5 ohms or less, go to next step.
3. 3) Check For Short Circuit Ensure ignition is off. Measure resistance between test pin No. 58 and test pins No. 33, 51 and 71 at breakout box. If any reading is 10,000 ohms or less, repair short circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If all readings are more than 10,000 ohms, go to next step.
4. 4) Check Rear Anti-Lock Brake System (RABS) Sensor Turn ignition off. Disconnect RABS sensor connector. Sensor is located on rear differential assembly. Measure resistance between sensor terminals. If resistance is not 1300-1550 ohms, replace RABS sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 1300-1550 ohms, go to next step.
5. 5) Check PSOM Output Voltage Turn ignition off. Connect PCM to breakout box. Connect wiring harness connector to PSOM. Set New Generation Star (NGS) scan tool for frequency measurement with a 4-volt DC scale. Connect NGS scan tool probes between test pins No. 33 and 58 at breakout box. Road test vehicle at 40 MPH or 60 MPH. Frequency should by 88-92 Hz at 40 MPH or 128-132 at 60 MPH. If frequency is as specified, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If frequency is not as specified, no fault is indicated at this time. Check for faulty instrument cluster, cruise control system or RABS.

Perform this test when directed by QUICK TEST. This test is intended to diagnose a faulty BOO switch circuit or PCM. To prevent replacement of good components, be aware following non-EEC related areas may be at fault

1. Brakelight bulb.
2. Brakelight switch or brakelight fuse.

Identifying Brake On/Off Switch Circuit. Scheme 291

1. 1) DTC P0703: Check BOO PID Using scan tool, access BOO PID from PID/DATA monitor menu. Turn ignition on. While observing PID, firmly depress and release brake pedal. If PID reading indicates ON only, go to next step. If PID reading does not indicate ON only, go to step 4).
2. 2) Check BOO Switch Turn ignition on. Disconnect BOO switch connector. If BOO PID reading switched to OFF, replace BOO switch. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If BOO PID reading did not switch to OFF, go to next step.
3. 3) Check For Short To Power Turn ignition off. Disconnect PCM 104-pin connector. Turn ignition on. Measure voltage between ground and Light Green wire at BOO switch wiring harness connector. If battery voltage is present, locate and repair short to power in Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If battery voltage is not present, inspect PCM connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors and go to step 12).
4. 4) Check BOO PID If BOO PID reading indicates OFF only, go to step 6). If BOO PID reading does not indicate OFF only, fault is intermittent. Go to step 13). NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 4) to step 6). No test procedures have been omitted.
5. 6) Check Fuse No. 1 Remove and inspect fuse No. 1 (15-amp) from instrument panel fuse block. If fuse is okay, go to step 9). If fuse is blown, go to next step.
6. 7) Check For Short to Ground Measure resistance between ground and Light Green/Red wire at BOO switch wiring harness connector. If resistance is less than 10,000 ohms, locate and repair short to ground in wiring harness between fuse block and BOO switch. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 10,000 ohms or more, go to next step.
7. 8) Check Circuit No. 511 For Short To Ground Disconnect PCM 104-pin connector. Measure resistance between ground and Light Green wire at BOO switch wiring harness connector. If resistance is less than 10,000 ohms, locate and repair short to ground in Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 10,000 ohms or more, inspect PCM connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors and go to step 12).
8. 9) Check For Open Circuit Measure resistance of Light Green/Red wire between BOO switch wiring harness connector and output side of No. 1 fuse holder. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in wiring harness between fuse block and BOO switch connector. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
9. 10) Check For Open BOO Switch Turn ignition on. Connect a jumper wire between BOO switch wiring harness connector terminals. Using scan tool, access BOO PID from PID/DATA monitor menu. If PID reading indicates ON, replace BOO switch. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If PID reading does not indicate ON, remove jumper wire and go to next step.
10. 11) Check For Open In Circuit No. 511 Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure resistance between Light Green at BOO switch wiring harness connector and test pin No. 92 at breakout box. If resistance is less than 5 ohms, reconnect all connectors and go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
11. 12) Confirm PCM Fault Turn ignition on. Using scan tool, access BOO PID from PID/DATA monitor menu. If PID reading switches from ON to OFF, no problem is indicated at this time. If PID reading does not switch from ON to OFF, replace PCM. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
12. 13) Check For Intermittent Open Or Short Circuit Ensure BOO switch is disconnected. Turn ignition on. Connect a jumper wire between BOO switch wiring harness connector terminals. Confirm BOO PID reading on scan tool indicates ON and brakelights are also on. While observing BOO PID, wiggle and bend small sections of wiring harness starting at BOO switch connector and working toward PCM. If fault is indicated (PID changes to OFF), isolate fault in wiring harness and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no fault is indicated, go to next step.
13. 14) Check For Intermittent Short To Power Remove fuse No. 1. Confirm BOO PID reading on scan tool indicates OFF and brakelights are also off. While observing BOO PID, wiggle and bend small sections of wiring harness starting at BOO switch connector and working toward PCM. If fault is indicated (PID changes to ON), isolate fault in wiring harness and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no fault is indicated, fault cannot be duplicated at this time. Reconnect all connectors and repeat QUICK TEST.

CIRCUIT TEST L - MALFUNCTION INDICATOR LIGHT (MIL)

Note. Malfunction Indicator Light (MIL) is also known as CHECK ENGINE light.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. STO/MIL circuit.
2. Powertrain Control Module (PCM).

Identifying Malfunction Indicator Light Circuit. Scheme 292

1. 1) Check MIL Fault If any Key On Engine Off (KOEO) or CONTINUOUS MEMORY DTCs are present, service DTCs prior to continuing with this test. If MIL is always on, go to next step. If MIL is not always on, go to step 3).
2. 2) Check Circuit No. 658 For Short To Ground Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Turn ignition on. If MIL is on, locate and repair short to ground in circuit No. 658 (Pink/Light Green wire). Reconnect all connectors and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If MIL is off, replace PCM. Reconnect all connectors and repeat QUICK TEST.
3. 3) MIL Always Off Disconnect Manifold Absolute Pressure (MAP) sensor. Start engine. If MIL is on, no problem is indicated at this time. Reconnect MAP sensor and clear DTCs. If MIL is off, reconnect MAP sensor, turn engine off and go to next step.
4. 4) Check Ignition Feed Circuit Turn ignition on. Measure voltage between ground and Red/Light Green wire at power side of No. 2 fuse holder at instrument panel fuse block. If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open circuit in Red/Light Green wire or replace defective ignition switch. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 5) Check Fuse Remove and inspect fuse No. 2 at instrument panel fuse block. If fuse is okay, go to next step. If fuse is blown, locate and repair short to ground in Red/Yellow wire. Replace fuse. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 6) Check For Open In Circuit No. 640 Ensure fuse No. 2 is removed. Remove MIL bulb. Measure resistance of Red/Yellow wire between non-powered side of No. 2 fuse holder and MIL bulb socket. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Red/Yellow wire. Reconnect all components, clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check MIL Bulb Check MIL bulb. If bulb is okay, go to next step. If bulb is bad, replace bulb. Clear DTCs and check MIL operation.
8. 8) Check Circuit No. 658 Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Pink/Light Green wire at MIL bulb socket and test pin No. 2 at breakout box. If resistance is less than 5 ohms, circuit No. 658 is okay. Replace PCM. Check MIL operation. If resistance is 5 ohms or more, locate and repair open circuit in Pink/Light Green wire. Reconnect all components, clear DTCs and check MIL operation.

CIRCUIT TEST M - EXHAUST BACKPRESSURE REGULATOR (EPR)

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. Exhaust Backpressure Regulator (EPR).
2. Wiring harness circuits (PWR GND and EPR Signal).
3. Powertrain Control Module (PCM).

Identifying Exhaust Backpressure Regulator Circuit & Connector Terminals. Scheme 293

1. 1) DTC P0475 This DTC indicates a circuit failure has occurred in EPR control solenoid circuit. Possible causes for this DTC are: Faulty EPR solenoid. Open or shorted circuit. Faulty PCM. Disconnect EPR connector. EPR is located on top of engine. Turn ignition off. Measure resistance between ground and terminal "A" (Black/Pink wire) at EPR wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Black/Pink wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
2. 2) Check EPR Coil Measure resistance between EPR terminals. If resistance is 2.5-12.0 ohms, go to next step. If resistance is not 2.5-12.0 ohms, replace EPR. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
3. 3) Check For Short To Power Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. While shaking wiring harness, measure voltage between ground and terminal "B" (Gray/Red wire) at EPR wiring harness connector. If battery voltage is not present, go to next step. If battery voltage is present, locate and repair short to power in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
4. 4) Check For Short To Ground Disconnect PCM connector. While shaking wiring harness, measure resistance between ground and terminal "B" (Gray/Red wire) at EPR wiring harness connector. If resistance stays at more than 10,000 ohms, go to next step. If resistance ever changes to 10,000 ohms or less, locate and repair short to ground in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
5. 5) Check For Open Circuit Ensure EPR is disconnected. Install Breakout Box (014-00950), leaving PCM disconnected. While shaking wiring harness, measure resistance of Gray/Red wire between EPR wiring harness connector and test pin No. 42 at breakout box. If resistance stays at less than 5 ohms, reconnect all components. Repeat «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) and KOER ON-DEMAND SELF-TEST. If DTC is still present, replace PCM. If resistance ever changes to 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
6. 6) Perform Output State Check Reconnect PCM connector. Attach New Generation Star (NGS) scan tool. Turn ignition on. Connect DVOM between ground and terminal "B" (Gray/Red wire) at EPR wiring harness connector. Using NGS scan tool, perform Output State Self-Test. See «ADDITIONAL SYSTEM FUNCTIONS»(ref-24260-S07311210122001010400000). If voltage does not toggle between 12 volts and zero volts, go to next step. If voltage toggles between 12 volts and zero volts, reconnect all components. Repeat «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) and KOER ON-DEMAND SELF-TEST. If DTC is still present, replace PCM.
7. 7) DTC P0476 This DTC indicates an Exhaust Backpressure Regulator (EPR) malfunction was detected during KOEO ON-DEMAND SELF-TEST. Possible causes for this DTC are: Stuck or damaged butterfly. Misadjusted or damaged linkage. Restricted exhaust. Exhaust leaks. Faulty EPR. Faulty Exhaust Backpressure (EBP) sensor. Faulty PCM. Repair any KOEO EBP sensor faults before continuing with this test. Visually inspect butterfly tang. (Scheme 287)in CIRCUIT TEST H. If tang is in Open position, go to next step. If tang is not in Open position, repair damaged linkage or butterfly as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
8. 8) Check For Exhaust Restriction Using scan tool, access EBP PID from PID/DATA monitor menu. Start engine. Briefly accelerate engine speed to Wide Open Throttle (WOT) while monitoring EBP PID. If EBP PID reading is less than 28 psi, go to next step. If EBP PID reading is 28 psi or more, repair restricted exhaust system. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
9. 9) Check EBP Sensor Turn ignition on. Using scan tool, access EBP PID from PID/DATA monitor menu. Start engine and record EBP PID reading. While observing scan tool, briefly accelerate engine several times. If EBP PID reading increases 4 psi or more, go to next step. If EBP PID reading does not increase 4 psi or more, replace EBP sensor and retest system.
10. 10) Check For Exhaust Leaks Inspect turbo pipe, crossover pipe and exhaust manifolds for leaks. Repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If no exhaust leaks are found, go to next step.
11. 11) Check EBP During KOEO Disconnect EBP sensor connector. Install ICP/EBP Adapter Cable (D94T-50-A) between EBP sensor and sensor wiring harness connector. Start engine. Measure voltage between signal circuit and signal ground at ICP/EBP adapter cable. Perform «KOER ON-DEMAND SELF-TEST»(ref-24260-S27861546292001010400000). If voltage increases 1.5-2.5 volts and then decreases as test ends, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If voltage does not increase 1.5-2.5 volts and then decreases as test ends, go to next step.
12. 12) EPR Visual Inspection Observe EPR valve linkage (turbocharger control rod) while performing «KOER ON-DEMAND SELF-TEST»(ref-24260-S27861546292001010400000). If control rod moves during test, check control rod adjustment. Spring scale reading should be 10 lbs. (4.5 kg). (Scheme 288) Adjust as necessary and retest. If control rod does not move during test, replace EPR valve. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).

Perform this test when directed by QUICK TEST. Brake Pressure Applied (BPA) switch is a pressure switch that senses brake pressure and is redundant with the Brake On/Off (BOO) switch to provide a back-up to deactivate cruise control.

Identifying Brake Pressure Applied Switch Circuit & Connector Terminals. Scheme 294

1. 1) DTC P0571: Check BPA Parameter Identification (PID) Using scan tool, access BPA PID from PID/DATA monitor menu. With brake pedal depressed, observe BPA PID reading. If BPA PID reading indicates ON only, go to next step. If BPA PID reading does not indicate ON only, go to step 5).
2. 2) Check BPA Switch Turn ignition on. Disconnect BPA switch. If BPA PID switches to OFF, replace BPA switch. Reconnect all connectors and recheck BPA PID. If BPA PID does not switch to OFF, go to step 4). NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 2) to step 4). No test procedures have been omitted.
3. 4) Check For Short To Power Turn ignition off. Disconnect PCM 104-pin connector. Turn ignition on. Measure voltage between ground and Red/Light Green wire at BPA switch wiring harness connector. If battery voltage is present, locate and repair short to power in Red/Light Green wire. Reconnect all connectors and recheck BPA PID. If battery voltage is not present, replace PCM. Reconnect all connectors, clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 5) Check BPA PID Using scan tool observe BPA PID reading. Depress and release brake pedal. If BPA PID reading indicates OFF only, go to step 7). If BPA PID reading does not indicate OFF only, fault may be intermittent. Go to step 14). NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 5) to step 7). No test procedures have been omitted.
5. 7) Check Fuse Remove and inspect fuse No. 1 (15-amp) from instrument panel fuse block. If fuse is blown, replace fuse. If fuse blows again, go to step 19). If fuse is okay, go to step 16). NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 7) to step 9). No test procedures have been omitted.
6. 9) Check For Short To Ground Disconnect PCM 104-pin connector. Measure resistance between ground and Black/Yellow wire at BPA switch wiring harness connector. If resistance is more than 10,000 ohms, go to step 21). If resistance is 10,000 ohms or less, locate and repair short to ground in Black/Yellow wire. Reconnect all connectors and recheck BPA PID. NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 9) to step 11). No test procedures have been omitted.
7. 11) Check For Open In Circuit No. 298 Turn ignition off. Measure resistance of Purple/Orange wire between BPA switch wiring harness connector and No. 5 fuse holder. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Purple/Orange wire. Reconnect all connectors and recheck BPA PID.
8. 12) Check For Open In Circuit No. 307 Disconnect jumper wire. Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Black/Yellow wire at BPA switch wiring harness connector and test pin No. 31 at breakout box. If resistance is less than 5 ohms, reconnect all connectors and go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Black/Yellow wire. Reconnect all connectors and recheck BPA PID.
9. 13) Confirm PCM Fault Turn ignition on. Using scan tool, access BPA PID from PID/DATA monitor menu. While observing BPA PID reading, depress and release brake pedal. If BPA PID switches from ON to OFF, no problem is indicated at this time. If BPA PID does not switch from ON to OFF, replace PCM. Reconnect all connectors and recheck BPA PID.
10. 14) Check For Intermittent Open Or Short Ensure BPA switch is disconnected. Turn ignition on. Connect a jumper wire between Red/Light Green wire and Light Green/Red wire at BPA switch wiring harness connector. Using scan tool, access BPA PID from PID/DATA monitor menu. BPA PID reading should indicate ON. While observing BPA PID, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (BPA PID switches to OFF), isolate fault and repair as necessary. Reconnect all connectors and recheck BPA PID. If no fault is indicated, go to next step.
11. 15) Check For Intermittent Short To Power Ensure jumper wire is still connected. Remove fuse No. 1 at instrument panel fuse block. Turn ignition on. Using scan tool, access BPA PID from PID/DATA monitor menu. BPA PID should indicate OFF. While observing BPA PID reading, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (BPA PID switches to ON), isolate fault and repair as necessary. Reconnect all components and recheck BPA PID. If no fault is indicated, no problem is indicated at this time. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
12. 16) Check For Open In Circuit No. 10 Turn ignition off. Measure resistance of Light Green/Red wire between BPA switch wiring harness connector and No. 1 fuse holder. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Light Green/Red wire. Reconnect all connectors and recheck BPA PID.
13. 17) Check For Open BPA Switch Reinstall fuse No. 1. Ensure BPA switch is disconnected. Turn ignition on. Connect a jumper wire between Red/Light Green wire and Light Green/Red wire at BPA switch wiring harness connector. Using scan tool, access BPA PID from PID/DATA monitor menu. If BPA PID reading indicates ON, replace BPA switch and retest. If BPA PID reading does not indicated ON, go to next step.
14. 18) Check For Open In Circuit No. 810 Disconnect jumper wire. Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance of Red/Light Green wire between BPA switch wiring harness connector and test pin No. 31 at breakout box. If resistance is less than 5 ohms, replace PCM and retest. If resistance is 5 ohms or more, locate and repair open circuit in Red/Light Green wire and retest.
15. 19) Check Circuit No. 10 For Short To Ground Remove fuse No. 1 at instrument panel fuse block. Measure resistance between ground and Light Green/Red wire at BPA switch wiring harness connector. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, locate and repair short to ground in Light Green/Red wire. Replace fuse and retest.
16. 20) Check Circuit No. 810 For Short To Ground Remove fuse No. 1 at instrument panel fuse block. Disconnect PCM 104-pin connector. Measure resistance between ground and Red/Light Green wire at BPA switch wiring harness connector. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, locate and repair short to ground in Red/Light Green wire. Replace fuse and retest.
17. 21) Check PCM For Internal Short Connect PCM connector to breakout box. Measure resistance between test pin No. 31 and test pins No. 25, 76, 77 and 103 at breakout box. If all readings are more than 10,000 ohms, no problem is indicated at this time. If any reading is 10,000 ohms or less, replace PCM. Reinstall fuse and retest.

Perform this test when directed by QUICK TEST. Parking Brake Applied (PBA) switch detects when parking brake is applied to enable Power Take-Off (PTO) raised-idle mode.

Parking Brake Applied Switch Circuit & Connector Terminals. Scheme 295

1. 1) DTC P1536 This DTC indicates that PCM does not detect a PBA state change during KOEO ON-DEMAND SELF-TEST. Possible causes for this fault are: Low brake fluid. Short to ground or power. Open circuit. Faulty Powertrain Control Module (PCM). Start engine and observe BRAKE warning and ABS warning lights (bulb check). If both lights are on, go to next step. If one or both lights are off, repair wiring in bulb circuit(s) as necessary. After repair is completed, perform bulb check again.
2. 2) Check For Brake System Problem Turn ignition on. Ensure parking brake is fully off. Check BRAKE warning and ABS warning lights. If both lights are on, a fault exists in brake system. Check and repair brake system as necessary. If one or both lights are off, go to next step.
3. 3) Check PBA Parameter Identification (PID) Using scan tool, access PBA PID from PID/DATA monitor menu. Observe PBA PID reading and cycle parking brake. If PBA PID reading indicates ON only, go to next step. If PBA PID reading does not indicate ON only, go to step 6).
4. 4) Check PBA Switch Turn ignition on. Disconnect PBA switch. If PBA PID switches to OFF, replace PBA switch. Reconnect all connectors and recheck PBA PID. If PBA PID does not switch to OFF, go to next step.
5. 5) Check For Short To Ground Turn ignition off. Disconnect PCM 104-pin connector. Measure resistance between ground and Purple/White wire at PBA switch wiring harness connector. If resistance is less than 10,000 ohms, locate and repair short to ground in Purple/White wire. Reconnect all connectors and recheck PBA PID. If resistance is 10,000 ohms or more, inspect PCM 104-pin connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors and go to step 9).
6. 6) Check PBA PID Using scan tool, observe PBA PID reading. Cycle parking brake. If PBA PID reading indicates OFF only, go to next step. If PBA PID reading does not indicate OFF only, fault may be intermittent. Go to step 10).
7. 7) Check PBA Switch Turn ignition on. Ensure PBA switch is disconnected. Connect a jumper wire between ground and Purple/White wire at PBA switch wiring harness connector. Using scan tool, check PBA PID reading. If PBA PID reading indicates ON, replace PBA switch. Reconnect all connectors and recheck PBA PID. If PBA PID reading does not indicate ON, go to next step.
8. 8) Check For Open In Circuit No. 977 Disconnect jumper wire. Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pin No. 5 at breakout box. If battery voltage is present, reconnect all connectors and go to next step. If battery voltage is not present, locate and repair open in circuit No. 162 (Light Green/Red wire) or circuit No. 977 (Purple/White wire). Reconnect all connectors and recheck PBA PID.
9. 9) Confirm PCM Fault Turn ignition on. Using scan tool, access PBA PID from PID/DATA monitor menu. While observing PBA PID reading, cycle parking brake. If PBA PID switches from ON to OFF, no problem is indicated at this time. If PBA PID does not switch from ON to OFF, replace PCM. Reconnect all connectors and recheck PBA PID.
10. 10) Check For Intermittent Short To Ground Ensure PBA switch is disconnected. Turn ignition on. Using scan tool, access PBA PID from PID/DATA monitor menu. PBA PID reading should indicate OFF. While observing PBA PID, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (PBA PID switches to ON), isolate fault and repair as necessary. Reconnect all connectors and recheck PBA PID. If no fault is indicated, go to next step.
11. 11) Check For Intermittent Open Engage parking brake. Using scan tool, access PBA PID from PID/DATA monitor menu. PBA PID should indicate ON. While observing PBA PID reading, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (PBA PID switches to OFF), isolate fault and repair as necessary. Reconnect all components and recheck PBA PID. If no fault is indicated, no problem is indicated at this time. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .

Perform this test when directed by QUICK TEST. Glow plugs are energized during and after WAIT TO START light is on. When WAIT TO START light turns off, engine is ready to be started. This CIRCUIT TEST is intended to diagnose

1. Warning light.
2. Wiring harness circuits (WAIT TO START light).
3. Powertrain Control Module (PCM).

Note. Glow plug and glow plug wiring harness problems cannot be detected by PCM.

Identifying Glow Plug Warning Light Circuit. Scheme 296

1. 1) DTC P0381 This DTC indicates that PCM has detected a glow plug warning light circuit malfunction. Possible causes for this fault are: Open WAIT TO START light. Open or grounded circuit. Blown fuse. Faulty Powertrain Control Module (PCM). Start engine and observe WAIT TO START light. If light stays on, go to next step. If light does not stay on, go to step 3).
2. 2) Check Circuit No. 464 For Short Turn ignition off. Disconnect PCM 104-pin connector. Turn ignition on. If WAIT TO START light is on, locate and repair short in circuit No. 464 (Black/Pink wire) between WAIT TO START light and PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If WAIT TO START light is off, replace PCM. Clear DTCs and repeat QUICK TEST.
3. 3) Check Intermittent DTC P0381 This DTC indicates that PCM has detected a WAIT TO START light circuit malfunction. Possible causes for this fault are: Intermittent open WAIT TO START light. Intermittent open or grounded circuit. Turn ignition off. Turn ignition on. If WAIT TO START light turns on for at least one second, go to step 9). If WAIT TO START light does not turn on for at least one second, go to next step.
4. 4) Check Fuse Turn ignition off. Check fuse No. 2. If fuse is okay, go to next step. If fuse is blown, go to step 6).
5. 5) Check Bulb Remove and inspect WAIT TO START bulb. If bulb is okay, go to next step. If bulb is bad, replace bulb. Reconnect all connectors, clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 6) Check For Short To Ground Ensure WAIT TO START bulb is removed. Measure resistance between ground and Red/Yellow wire at WAIT TO START bulb socket. If resistance is more than 10,000 ohms, replace fuse. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 10,000 ohms or less, locate and repair short to ground in Red/Yellow wire. Replace fuse. Clear DTCs and repeat QUICK TEST.
7. 7) Check For Open Circuit Turn ignition on. Measure voltage between ground and Red/Yellow wire at WAIT TO START light wiring harness connector. If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open circuit in Red/Yellow wire between fuse and WAIT TO START light. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
8. 8) Check For Open In Circuit No. 464 Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Black/Pink wire at WAIT TO START light wiring harness connector and test pin No. 70 at breakout box. If resistance is less than 5 ohms, replace PCM. Reconnect all connectors. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Black/Pink wire. Clear DTCs and repeat QUICK TEST.
9. 9) Continuous Memory DTC P0381 Clear DTCs. Road test vehicle and recheck for DTCs. If P0381 is present, go to next step. If P0381 is not present, DTC was not cleared after a previous repair. Testing is complete.
10. 10) Check For KOER P0381 Road test vehicle. If WAIT TO START light turns on or flickers during road test, locate and repair intermittent short to ground in Black/Pink wire between PCM and WAIT TO START light. If WAIT TO START light does not turn on or flicker during road test, go to next step.
11. 11) Check For Intermittent Open Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Using a jumper wire, ground test pin No. 70. While observing WAIT TO START light, tap on dashboard. Wiggle and bend small sections of wiring harness starting at 76-pin bulkhead connector and working toward PCM. Bulkhead connector is located at firewall in left rear of engine compartment. If WAIT TO START light flickers on and off, locate and repair intermittent open circuit in Black/Pink wire between PCM and WAIT TO START light. If WAIT TO START light does not flicker on and off, no problem is indicated at this time. Testing is complete.

Perform this test when directed by QUICK TEST. Glow plug relay controls current flow to glow plugs. Glow plug relay "On" time is controlled by Powertrain Control Module (PCM) and is a function of engine oil temperature, barometric pressure and battery voltage. Glow plug "On" time varies between 10-120 seconds. This CIRCUIT TEST is intended to diagnose

1. Glow plug relay.
2. Harness circuits (GP/RELAY coil).
3. Powertrain Control Module (PCM).

Identifying Glow Plug Relay Circuits. Scheme 297

1. 1) DTC P1391, P1393, P1395 & P1396 DTC P1395 or P1396 will set if a cylinder bank has a voltage reading of less than 32-amps or if a cylinder bank has a voltage reading of 8 1/2 volts less than the other cylinder bank. DTC P1391 or P1393 indicates all 4 glow plugs on one bank are not being powered. Both P1391 and P1393 output together indicates all 8 glow plugs are not being powered. Possible causes for this fault are: Faulty glow plug relay. Faulty glow plug shunt. Open in glow plug circuit(s). Faulty glow plug(s). Faulty Powertrain Control Module (PCM). NOTE: Glow plugs are not energized if Engine Operating Temperature (EOT° is more than 131°F (55°C). Turn ignition on. Using scan tool, select EOT PID from PID/DATA monitor menu. Verify EOT PID value is less than 120°F (49°C). Measure voltage between ground and Black/Orange wire at glow plug relay. Relay is located on top of engine. If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open circuit in Black/Orange wire between glow plug relay and starter relay fusible links. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
2. 2) Check For DTC P0380 Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000). Retrieve DTCs. If DTC P0380 is present, go to next step. If DTC P0380 is not present, go to step 8).
3. 3) DTC P0380 This DTC indicates that PCM has detected a glow plug relay control circuit malfunction. Possible causes for this fault are: Short to power. Blown fuse. Faulty glow plug relay. Open or grounded circuit. Faulty Powertrain Control Module (PCM). Turn ignition on. Measure voltage between ground and terminal "B" (Red/Light Green wire) at glow plug relay. (Scheme 297) If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open circuit in Red/Light Green wire. If fuse is blown, check for short to ground in Red/Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
4. 4) Check Glow Plug Relay Turn ignition off. Disconnect terminal "A" (Purple/Orange wire) at glow plug relay. Measure resistance between terminals "A" and "B" at glow plug relay. If resistance is 1-8 ohms, go to next step. If resistance is not 1-8 ohms, replace glow plug relay. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
5. 5) Check For Short To Power Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pin No. 101 at breakout box. If battery voltage is present, repair short to power. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If battery voltage is not present, go to next step.
6. 6) Check For Short To Ground Turn ignition off. Ensure terminal "A" (Purple/Orange wire) at glow plug relay is disconnected. Measure resistance between ground and disconnected Purple/Orange wire. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, locate and repair short to ground in Purple/Orange wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
7. 7) Check For Open Circuit Measure resistance of Purple/Orange wire between glow plug relay and test pin No. 101 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance is 5 ohms or more, locate and repair open circuit in Purple/Orange wire. Clear DTCs and repeat QUICK TEST.
8. 8) Check Glow Plug Relay Turn ignition on. Using scan tool, select EOT and GPCTM PIDs from PID/DATA monitor menu. Verify EOT PID value is less than 120°F (49°C). NOTE: Glow plugs are not energized if EOT is more than 131°F (55°C). GPCTM PID value can be used to verify glow plug "On" time. Measure voltage between ground and center terminal (Gray wire) at glow plug shunt. If voltage is present for 30 seconds or more, go to next step. If voltage is not present for 30 seconds or more, replace glow plug relay. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
9. 9) Check Glow Plug Turn ignition off. On cylinder bank that set DTC, disconnect both valve cover gasket connectors. Install Glow Plug Injector Adapter (014-00935) to valve cover gasket. Measure resistance between ground and each of the 4 glow plug circuits on glow plug injector adapter. If resistance is 2 ohms or more, go to next step. If resistance is less than 2 ohms, go to step 11) (for DTCs P1391 and P1395) or step 12) (for DTCs P1393 and DTC P1396).
10. 10) Check Valve Cover Gasket Remove valve cover and check glow plug connections. Repair as necessary. If connections are okay, disconnect suspect glow plug connector. Measure resistance between ground and suspect glow plug. If resistance is less than 2 ohms, replace valve cover gasket or Under Valve Cover (UVC) wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance is 2 ohms or more, replace glow plug. Clear DTCs and repeat QUICK TEST.
11. 11) Check Glow Plug Monitoring Circuit - DTCs P1391 & P1395 Disconnect all 4 valve cover connectors at both left and right cylinder banks. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 9 at breakout box and all 4 glow plug circuits at right cylinder bank. If all readings are within 2 ohms of each other, go to step 13). If any reading is not within 2 ohms of each other, locate and repair open circuit between valve cover connector and PCM. Verify glow plug shunt nuts are clean and tight. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
12. 12) Check Glow Plug Monitoring Circuit - DTCs P1393 & P1396 Measure resistance between test pin No. 34 at breakout box and all 4 flow plug circuits at left cylinder bank. If all readings are within 2 ohms of each other, go to next step. If any reading is not within 2 ohms of each other, locate and repair open circuit between valve cover connector and PCM. Verify glow plug shunt nuts are clean and tight. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
13. 13) Check For Open Circuit Measure resistance of Gray wire between center terminal of glow plug shunt and test pin No. 8 at breakout box. If resistance is less than 2 ohms, go to next step. If resistance is 2 ohms or more, locate and repair open circuit in Gray wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
14. 14) Compare Right Bank To Left Bank Measure resistance between all 4 glow plug circuits at left cylinder bank and test pins No. 8, 9 and 34. Also, measure resistance between all 4 glow plug circuits at right cylinder bank and test pins No. 8, 9 and 34. If all readings are within 2 ohms of each other, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If any reading is not within 2 ohms of each other, repair open in circuit with higher resistance reading. Verify glow plug shunt nuts are clean and tight. Clear DTCs and repeat QUICK TEST.
15. 15) DTC P1397 This DTC will set if system voltage is more than 14 volts or less than 11.8 volts at any time during KOEO GLOW PLUG MONITORING SELF-TEST. NOTE: During KOER GLOW PLUG MONITORING SELF-TEST It may be necessary to raise engine RPM to maintain system voltage. If unable to maintain system voltage, repair charging system as necessary. Connect a DVOM to battery. Perform «KOER GLOW PLUG MONITORING SELF-TEST»(ref-24260-S03543226382001010400000). Maintain system voltage until test is complete. If P1397 is still present, go to «CIRCUIT TEST A»(ref-24260-S17790910942001010400000). If P1397 is not present, no problem is indicated at this time. Testing is compete.

Perform this test when directed by QUICK TEST. FDCS controls fuel injection timing and controls fuel quantity with Injection Pressure Regulator (IPR). This signal is sent with the Cylinder Identification (CID) signal to the Injector Driver Module (IDM) which provides power and distributes the proper signal to appropriate injector. This CIRCUIT TEST is intended to diagnose

1. Injector driver module.
2. Wiring harness circuit (FDCS).
3. Powertrain Control Module (PCM).

Identifying Fuel Delivery Command Signal Circuit. Scheme 298

1. 1) DTC P1663 This DTC indicates that PCM has detected a FDCS circuit malfunction. Possible causes for this fault are: Faulty Injector Driver Module (IDM). Open or grounded circuit. Faulty Powertrain Control Module (PCM). Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950) and connect PCM connector to breakout box. Turn ignition on. Measure voltage between ground and test pin No. 95 at breakout box. If voltage is .5-.7 volt, go to next step. If voltage is less than .5 volt, go to step 3). If battery voltage is present, go to step 4).
2. 2) Perform Output State Check Turn ignition on. Using NGS scan tool, perform Output State Self-Test. See «ADDITIONAL SYSTEM FUNCTIONS»(ref-24260-S07311210122001010400000) . Measure voltage between ground and test pin No. 95 at breakout box while depressing and releasing accelerator pedal. If voltage does not toggle between .5-.7 volt and 12 volts, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage toggles between .5-.7 volt and 12 volts, fault is intermittent. Go to step 7).
3. 3) Check Circuit No. 821 Turn ignition off. Disconnect PCM connector from breakout box. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Measure resistance between terminal No. 17 (Brown/Orange wire) at IDM connector and test pin No. 95 at breakout box. If resistance is less than 5 ohms, go to step 5). If resistance is 5 ohms or more, locate and repair open circuit in Brown/Orange wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check For Short To Power Turn ignition on. Measure voltage between ground and test pin No. 95 at breakout box. If battery voltage is not present, go to step 6). If battery voltage is present, locate and repair short to power in Brown/Orange wire between PCM connector and IDM connector.
5. 5) Check For Short To Ground Turn ignition off. Measure resistance between test pin No. 95 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, locate and repair short to ground in Brown/Orange wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 6) Check PCM Connect PCM to breakout box. Ensure IDM is disconnected. Turn ignition on. Using NGS scan tool, perform Output State Self-Test. See «ADDITIONAL SYSTEM FUNCTIONS»(ref-24260-S07311210122001010400000) . Measure voltage between ground and test pin No. 95 at breakout box while depressing and releasing accelerator pedal. If voltage does not toggle between .5-.7 volt and zero volts, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage toggles between .5-.7 volt and zero volts, replace IDM. Clear DTCs and repeat QUICK TEST.
7. 7) Check For Intermittent Clear DTCs. Start engine and allow it to idle. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If DTC P1663 is present, locate and repair intermittent in wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1663 is not present, no problem is indicated at this time.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. Injector Driver Module (IDM).
2. Wiring harness circuit (EF).
3. Powertrain Control Module (PCM).

Identifying Injector Driver Module Feedback Circuit. Scheme 299

1. 1) DTC P1668 This DTC indicates a PCM/IDM communication error. Possible causes for this fault are: Faulty Injector Driver Module (IDM). Open or grounded circuit. Faulty Powertrain Control Module (PCM). Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) again. If DTC P1668 is not present, go to next step. If only DTC P1668 is present, go to step 3). If DTCs P1663, P1667 and P1668 are present, go to step 8). If DTC P1668 is present with DTC P1298 or P1667, go to «CIRCUIT TEST V»(ref-24260-S09696612112001010400000) . If DTCs P1668 and P1663 are present, go to «CIRCUIT TEST T»(ref-24260-S38844679102001010400000) . If DTCs P1668 and P1662 are present, go to «CIRCUIT TEST W»(ref-24260-S26019898632001010400000) .
2. 2) Check EF Circuit Start engine and allow it to idle. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If DTC P1668 is present, locate and repair intermittent in wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1668 is not present, no problem is indicated at this time.
3. 3) Check Circuit No. 818 Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Measure resistance between terminal No. 4 (Gray/White wire) at IDM connector and test pin No. 48 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check For Short To Ground Turn ignition off. Measure resistance between test pin No. 48 and test pins No. 25, 51, 76, 77 and 103 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground in Gray/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 5) Check For Short To Power Reconnect PCM to breakout box. Measure resistance between test pin No. 48 and test pins No. 55, 71 and 91 at breakout box. If any reading is 10,000 ohms or less, locate and repair short to power in Gray/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If all readings are more than 10,000 ohms, go to next step.
6. 6) Check SIG RTN Circuit Measure resistance of Gray/Red wire between test pin No. 91 at breakout box and terminal No. 2 at IDM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check IDM Power Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Turn ignition on. Measure voltage between ground and terminal No. 14 (Dark Green/Light Green wire) at IDM wiring harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to «CIRCUIT TEST W»(ref-24260-S26019898632001010400000) .
8. 8) Check IDM Ground Turn ignition off. Measure resistance between ground and terminal No. 26 (Black/White wire) at IDM connector. If resistance is less than 5 ohms, replace IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Black/White wire. Clear DTCs and repeat QUICK TEST.
9. 9) Measure EF Circuit Frequency Reconnect IDM connector. Start engine and allow it to idle. Using New Generation Star (NGS) scan tool, select frequency meter. Use 4V DC scale. Using a jumper wire, connect test pin No. 48 of breakout box to SIG INPUT on scan tool. Using another jumper wire, connect test pin No. 77 (ground) of breakout box to COMMON on scan tool. Measure frequency at specified engine RPM. See IDM FREQUENCY SPECIFICATIONS table. If frequency is not as specified, replace IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If frequency is as specified, replace PCM. Clear DTCs and repeat QUICK TEST. IDM FREQUENCY SPECIFICATIONS Engine RPM Frequency (Hz) 1000 66 2000 133 3000 200
10. 10) DTC P1316 This DTC indicates IDM DTCs are stored in the IDM. Injector faults are stored in the IDM and reported to PCM during KOEO ON-DEMAND SELF-TEST and KOEO INJECTOR ELECTRICAL SELF-TEST. An intermittent fault will store a DTC in the IDM. IDM DTCs are cleared by using CLEAR ALL command from the RETRIEVE/CLEAR CONTINUOUS DTCs menu on scan tool. Possible causes for this fault are: Faulty Injector Driver Module (IDM). Open or grounded circuit. Faulty Powertrain Control Module (PCM). Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) again. If any IDM DTCs are present, perform appropriate circuit test and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no IDM DTCs are present, go to next step.
11. 11) Verify DTC P1316 Resets Clear Continuous Memory DTCs. Road test vehicle. Retrieve and clear Continuous Memory DTCs. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . Retrieve DTCs. If DTC P1316 is present in continuous memory with any KOEO IDM DTCs, perform appropriate circuit test and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1316 is present in continuous memory without any KOEO IDM DTCs, go to next step (if only DTC P1316 is present) or perform appropriate circuit test (if any other Continuous Memory DTCs are present).
12. 12) Check For Open Circuit Turn ignition off. Disconnect IDM connector. IDM is located in left side of engine compartment. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between terminal No. 4 (Gray/White wire) at IDM connector and test pin No. 48 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 5 ohms or less, go to next step. If resistance changes to more than 5 ohms, locate and repair open circuit in Gray/White wire between PCM and IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
13. 13) Check For Intermittent Short To Ground Measure resistance between ground and test pin No. 48 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 10,000 ohms or more, go to next step. If resistance changes to less than 10,000 ohms, locate and repair short to ground in Gray/White wire between PCM and IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
14. 14) Check For Intermittent Short To Power Turn ignition on. Measure voltage between ground and test pin No. 48 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If no voltage is ever present, go to next step. If any voltage is present, locate and repair short to power in Gray/White wire between PCM and IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
15. 15) Check For Intermittent Open Circuit Turn ignition off. Measure resistance of Brown/Orange wire between terminal No. 17 at IDM wiring harness connector and test pin No. 95 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 5 ohms or less, go to next step. If resistance changes to more than 5 ohms, locate and repair open circuit in Brown/Orange wire between PCM and IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
16. 16) Check For Intermittent Short To Ground Measure resistance between ground and test pin No. 95 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 10,000 ohms or more, go to next step. If resistance changes to less than 10,000 ohms, locate and repair short to ground in Brown/Orange wire between PCM and IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
17. 17) Check For Intermittent Short To Power Turn ignition on. Measure voltage between ground and test pin No. 95 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If no voltage is ever present, go to next step. If any voltage is present, locate and repair short to power in Brown/Orange wire between PCM and IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
18. 18) Verify DTC P1316 Resets Clear Continuous Memory DTCs. Road test vehicle. Retrieve and clear Continuous Memory DTCs. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . Retrieve DTCs. If DTC P1316 is present in continuous memory with any KOEO IDM DTCs, perform appropriate circuit test and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1316 is present in continuous memory without any KOEO IDM DTCs, go to next step.
19. 19) Attempt To Generate IDM DTCs Disconnect one fuel injector connector. Start engine to generate IDM DTCs. Perform «KOEO INJECTOR ELECTRICAL SELF-TEST»(ref-24260-S09777461152001010400000) . Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If any IDM DTCs are present, replace PCM. Reconnect all connectors, clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no IDM DTCs are present, replace IDM. Reconnect all connectors, clear DTCs and repeat QUICK TEST.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. Injector Driver Module (IDM).
2. Wiring harness circuit (CID).
3. Powertrain Control Module (PCM).

Identifying Cylinder Identification Circuit. Scheme 300

1. 1) DTCs P1218, P1219, P1298, P1667 & P1668 These DTCs indicate that PCM has detected a Cylinder Identification (CID) malfunction. Possible causes for this fault are: Faulty Injector Driver Module (IDM). Open or grounded circuit. Faulty Powertrain Control Module (PCM). Perform the following: If only DTC P1668 is present, go to «CIRCUIT TEST U»(ref-24260-S36408390362001010400000) . If DTCs P1668 and P1667 are present, go to next step. If DTCs P1663, P1667 and P1668 are present, go to «CIRCUIT TEST U»(ref-24260-S36408390362001010400000) , step 8). If only DTC P1298 is present, replace IDM. If only DTC P1667 is present, go to next step. If DTCs P1663 and P1667 are present, go to «CIRCUIT TEST U»(ref-24260-S36408390362001010400000) , step 8).
2. 2) Check CID Signal Circuit DTC P1667 or DTCs P1167 and P1668 retrieved together indicates there is a short to power, short to ground or an open at CID circuit. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950). Connect PCM connector to breakout box. Turn ignition on. Measure voltage between ground and test pin No. 96 at breakout box. If voltage is .5-.7 volt, go to next step. If voltage is less than .5 volt, go to step 4). If battery voltage is present, go to step 5).
3. 3) Perform Output State Check Attach New Generation Star (NGS) scan tool. Turn ignition on. Using NGS scan tool, perform Output State Self-Test. See «ADDITIONAL SYSTEM FUNCTIONS»(ref-24260-S07311210122001010400000) . Measure voltage between ground and test pin No. 96 at breakout box. If voltage does not toggle between .5-.7 volt and 12 volts, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage toggles between .5-.7 volt and 12 volts, fault is intermittent. Go to step 8).
4. 4) Check Circuit No. 817 Turn ignition off. Disconnect PCM connector from breakout box. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Measure resistance between terminal No. 16 (Yellow/Light Blue wire) at IDM connector and test pin No. 96 at breakout box. If resistance is less than 5 ohms, go to step 6). If resistance is 5 ohms or more, locate and repair open circuit in Yellow/Light Blue wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 5) Check For Short To Power Turn ignition on. Measure voltage between ground and test pin No. 96 at breakout box. If battery voltage is present, locate and repair short to power in Yellow/Light Blue wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If battery voltage is not present, go to step 7).
6. 6) Check For Short To Ground Turn ignition off. Measure resistance between test pin No. 96 and test pins No. 25, 51, 76, 77 and 103 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground in Yellow/Light Blue wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check Output State Check Ensure IDM is disconnected. Connect PCM connector to breakout box. Attach New Generation Star (NGS) scan tool. Turn ignition on. Using scan tool, perform Output State Self-Test. See «ADDITIONAL SYSTEM FUNCTIONS»(ref-24260-S07311210122001010400000) . Measure voltage between ground and test pin No. 96 at breakout box while depressing and releasing accelerator pedal. If voltage does not toggle between .5-.7 volt and zero volts, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage toggles between .5-.7 volt and zero volts, replace IDM. Clear DTCs and repeat QUICK TEST.
8. 8) Check For Intermittent Clear DTCs. Start engine and allow it to idle. Using an insulated tool, wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If any DTCs are present, locate and repair intermittent in wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no DTCs are present, no problem is indicated at this time.
9. 9) DTC P1219 P1219 is a IDM Continuous Memory DTC that is retrieved during KOEO ON-DEMAND SELF-TEST. This DTC indicates that PCM has detected a intermittent short to ground in CID circuit. Possible causes for this fault are: Short to ground. Faulty Injector Driver (IDM). Turn ignition off. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between ground and test pin No. 96 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance changes to less than 10,000 ohms, locate and repair short to ground in Yellow/Light Blue wire in wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance does not change to less than 10,000 ohms, reconnect PCM and IDM. Road test vehicle. If DTC resets, replace IDM. Clear DTCs and repeat QUICK TEST.
10. 10) DTC P1218 P1218 is a IDM Continuous Memory DTC that is retrieved during KOEO ON-DEMAND SELF-TEST. This DTC indicates that PCM has detected a intermittent short to power in CID circuit. Possible causes for this fault are: Faulty circuit. Faulty Injector Driver (IDM). Turn ignition off. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between terminal No. 16 (Yellow/Light Blue wire) at IDM connector and test pin No. 96 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If any voltage is indicated, locate and repair short to power in Yellow/Light Blue wire in wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no voltage is indicated, reconnect PCM and IDM. Road test vehicle. If DTC resets, replace IDM. Clear DTCs and repeat QUICK TEST.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. Injector Driver Module (IDM) relay.
2. Powertrain Control Module (PCM).
3. Wiring harness circuit (IDM-EN).

Identifying Injector Driver Module Enable (IDM-EN) Circuit. Scheme 301

1. 1) DTCs P1662: Check Circuit No. 814 This DTC indicates that PCM has detected a IDM-EN circuit malfunction. Possible causes for this fault are: Faulty IDM relay. Open IDM-EN circuit. Blow fuse. Faulty Powertrain Control Module (PCM). Remove IDM relay from engine compartment power distribution box. Turn ignition on. Measure resistance between ground and White/Black wire at IDM relay wiring harness connector. If resistance is 100 ohms or more, go to next step. If resistance is less than 100 ohms, go to step 3).
2. 2) Check For Open Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance of White/Black wire between IDM relay wiring harness connector and test pin No. 80 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in White/Black wire between PCM connector and IDM connector.
3. 3) Check Circuit No. 361 Remove PCM relay from power distribution box. Measure resistance of Red wire between PCM relay wiring harness connector and IDM relay wiring harness connector. If resistance is less than 5 ohms, reinstall PCM relay and go to step 9). If resistance is 5 ohms or more, locate and repair open circuit in Red wire. NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 3) to step 5). No test procedures have been omitted.
4. 5) Check For Open Circuit Ensure No. 8 fuse is removed. Measure resistance of Yellow wire between non-powered side of No. 8 fuse holder and IDM relay connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Yellow wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 6) Check Circuit No. 876 Disconnect Injector Driver Module (IDM) 40-pin connector. IDM is located on left side of engine compartment. Measure resistance of Dark Green/Light Green wire between IDM relay connector and terminal No. 14 at IDM connector. If resistance is less than 5 ohms, go to step 10). If resistance is 5 ohms or more, locate and repair open circuit in Dark Green/Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 7) Check IDM Relay Reinstall IDM relay. Ensure No. 8 fuse is removed and IDM is disconnected. Turn ignition on. Measure resistance between non-powered side of No. 8 fuse holder (Yellow wire) and terminal No. 14 (Dark Green/Light Green wire) at IDM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace IDM relay. Reconnect all connectors. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 8) Check IDM Ground Circuit Measure resistance of Black/White wire between ground and terminal No. 26 at IDM connector. If resistance is less than 5 ohms, replace IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Black/White wire. Clear DTCs and repeat QUICK TEST.
8. 9) Check Voltage At IDM Relay Turn ignition off. Measure voltage between ground and Yellow wire at IDM relay wiring harness connector. If battery voltage is present, go to step 6). If battery voltage is not present, locate and repair open circuit in Yellow wire between IDM relay and starter relay. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
9. 10) Check IDM Relay Install IDM relay. Ensure IDM is disconnected. Turn ignition on. Measure voltage between ground and terminal No. 14 (Dark Green/Light Green wire) at IDM connector. If battery voltage is present, go to step 8). If battery voltage is not present, replace IDM relay. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. Injection Pressure Regulator (IPR).
2. Injection Control Pressure (ICP) sensor.
3. Powertrain Control Module (PCM).
4. Wiring harness circuit (IPR).

Identifying Injection Pressure Regulator Circuit. Scheme 302

1. 1) DTCs P1283: Check Power Feed Circuit This DTC indicates that PCM has detected a IPR circuit malfunction. Turn ignition off. Disconnect IPR connector. IPR is mounted on high pressure oil pump, located on top of engine. Remove PCM relay from power distribution box in engine compartment. Measure resistance of Red wire between IPR connector and PCM relay wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
2. 2) Check IPR Coil Resistance Measure resistance between IPR terminals. If resistance is 5-20 ohms, go to next step. If resistance is not 5-20 ohms, replace IPR. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
3. 3) Check IPR Control Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 83 and test pins No. 71 and 97 at breakout box. Also, measure resistance between test pin No. 83 and test pins No. 25, 51, 76, 77 and 103 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground or power in Yellow/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check Wiring Harness Continuity Check for continuity in Yellow/Red wire between test pin No. 83 at breakout box and IPR wiring harness connector. If continuity exists, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If continuity does not exist, locate and repair open circuit in Red/Yellow wire. Clear DTCs and repeat QUICK TEST.
5. 5) DTC P1282: Excessive Injection Control Pressure This DTC indicates excessive injection control pressure was detected during continuous diagnostic monitoring. Possible causes for this fault are: Intermittent short to ground in IPR circuit. Stuck IPR. Turn ignition off. Disconnect IPR connector. IPR is located on top of engine. Attempt to start vehicle. If engine starts, replace IPR. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If engine does not start, go to next step.
6. 6) Check For Intermittent Short To Ground Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between ground and test pin No. 83 at breakout box. Resistance should be more than 10,000 ohms. Wiggle and bend small sections of wiring harness starting at IPR connector and working toward PCM. If fault is indicated (resistance 10,000 ohms or less), isolate fault and repair as necessary. Reconnect all connectors. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no fault is indicated, no problem is indicated at this time. Clear DTCs and repeat QUICK TEST. If DTC resets, replace PCM.
7. 7) KOER DTC P1211 This DTC indicates that control pressure was high/low during SELF-TEST. Possible causes for this fault are: Low reservoir oil level. Poor oil quality. Injector "O" ring leak. Faulty IPR valve. Faulty Injection Control Pressure (ICP) sensor. Faulty oil pressure pump. Faulty Powertrain Control Module (PCM). Verify correct oil quality, viscosity and fuel grade are being used for temperature conditions. Replace oil/fuel as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If oil/fuel are okay, go to next step.
8. 8) Check Fuel Pressure Measure fuel pressure at regulator block. Check pressure with engine idling and while driving vehicle with a full load. For fuel pressure specifications, see «FUEL PRESSURE SPECIFICATIONS»(ref-123323) article. Fuel pressure should be within specifications at idle and while driving vehicle with a full load. If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, repair fuel system as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
9. 9) Check Oil Reservoir Level Remove plug in top of oil reservoir and check level. If oil level is within 1" (25.4 mm) go to next step. If oil level is not within 1" (25.4 mm), check and repair cause of low fluid. Top off fluid. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
10. 10) Check Injection Control Pressure (ICP) Sensor Using scan tool, access ICP PID from PID/DATA monitor menu. Turn ignition on. If ICP PID reading indicates zero psi, go to next step. If ICP PID reading does not indicate zero psi, replace ICP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
11. 11) Check For Oil Aeration Again, using scan tool, access ICP PID from PID/DATA monitor menu. Ensure ignition is on (engine off). Depress accelerator pedal to wide open throttle for 3 minutes. If ICP PID reading increases to more than 1250 psi, change oil and repeat test. If ICP PID reading does not increase to more than 1250 psi, go to next step.
12. 12) Check ICP Sensor Disconnect ICP sensor connector. Install ICP/EBP Adapter Cable (D94T-50-A) between ICP sensor and sensor wiring harness connector. Start engine. Measure voltage between ICP signal circuit and ground at ICP/EBP adapter cable. Perform «KOER ON-DEMAND SELF-TEST»(ref-24260-S27861546292001010400000) . If voltage increases to more than 3 volts and then decreases to about one volt during ICP portion of test, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage does not increase to more than 3 volts and then decrease to about one volt during ICP portion of test, go to next step.
13. 13) Injector Leak Check Disconnect high pressure hose from right cylinder head. Using Oil High Pressure Leakage Adapter Set (D94T-6600-A), plug right high pressure hose. Using scan tool, monitor IPR PID reading. Start engine and record IPR PID reading. Turn ignition off. Reconnect right cylinder head high pressure hose. Disconnect high pressure hose from left cylinder head. Using oil high pressure leakage adapter set, plug left high pressure hose. Again, monitor IPR PID reading. Start engine and record IPR PID reading. If IPR PID readings are not within 2 percent of each other, repair internal oil leak on cylinder head with the higher IPR PID reading. If both IPR PID readings are within 2 percent of each other, replace IPR and retest system. If DTC P1211 is still set, go to next step.
14. 14) Check Oil System Pressure Perform INJECTION CONTROL PRESSURE TEST and check for pressurized oil leaks. See HARD START/NO START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article. Repair as necessary. If no leaks are found, replace high pressure oil pump.
15. 15) DTC P1209 Or P1211 These DTCs indicate that injector control pressure was not to specification during normal driving conditions. Possible causes for this fault are: Low reservoir oil level. Poor oil quality. Injector "O" ring leak. Faulty IPR valve. Faulty oil pressure pump. Faulty Powertrain Control Module (PCM). Verify correct oil quality, viscosity and fuel grade are being used for temperature conditions. Replace oil/fuel as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If oil/fuel are okay, go to next step.
16. 16) Check Fuel Pressure Measure fuel pressure at regulator block. Check pressure with engine idling and while driving vehicle with a full load. For fuel pressure specifications, see «FUEL PRESSURE SPECIFICATIONS»(ref-123323) article. Fuel pressure should be within specifications at idle and while driving vehicle with a full load. If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, repair fuel system as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
17. 17) Perform KOER ON-DEMAND SELF-TEST Perform «KOER ON-DEMAND SELF-TEST»(ref-24260-S27861546292001010400000) . If DTC P1211 is present, go to step 9). If DTC P1211 is not present, go to next step.
18. 18) Check Oil Reservoir Level Remove plug in top of oil reservoir and check level. If oil level is within 1" (25.4 mm) go to next step. If oil level is not within 1" (25.4 mm), check and repair cause of low fluid. Top off fluid. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
19. 19) Check Injection Control Pressure (ICP) Sensor Using scan tool, select ICP PID from PID/DATA monitor menu. If ICP PID reading indicates zero psi, go to next step. If ICP PID reading does not indicate zero psi, replace ICP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
20. 20) Check For Oil Aeration Again, using scan tool, select ICP PID from PID/DATA monitor menu. Start engine. Raise engine speed to 3300 RPM, and hold for 3 minutes. If ICP PID reading increases to more than 1250 psi, change oil and repeat test. If ICP PID reading does not increase to more than 1250 psi, go to next step.
21. 21) Check IPR Duty Cycle Using scan tool, select IPR PID from PID/DATA monitor menu. Road test vehicle at wide open throttle and full load condition. If IPR PID value increases to 65 percent, replace IPR valve. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If IPR PID value does not increase to 65 percent, no problem is indicated at this time. Clear DTCs and repeat QUICK TEST.

Perform this test only when directed by QUICK TEST. Glow plug relay and glow plug light "On" time are controlled by engine oil temperature. This test is intended to diagnose

1. EOT sensor.
2. Wiring harness circuits (EOT and SIG RTN).
3. Faulty Powertrain Control Module (PCM).

Identifying EOT Sensor Circuit. Scheme 303

EOT SENSOR SPECIFICATIONS

1. 1) DTC P0198 This DTC indicates EOT sensor is out of self-test range (high). Possible causes for this fault are: Open circuit. Faulty EOT sensor. Faulty Powertrain Control Module (PCM). Turn ignition off. Disconnect EOT sensor connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Measure resistance between ground and Gray/Red wire at EOT sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire (SIG RTN circuit). Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
2. 2) Induce Opposite Failure Turn ignition on. Connect a jumper wire between EOT sensor wiring harness connector terminal. Check for DTCs. If DTC P0197 is present, replace EOT sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P0197 is not present, go to next step.
3. 3) Check For Open Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Light Green/Red wire at EOT sensor wiring harness connector and test pin No. 38 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Light Green/Red wire. Clear DTCs and repeat QUICK TEST.
4. 4) DTC P0197: Induce Opposite Failure This DTC indicates EOT sensor is out of self-test range (low). Possible causes for this fault are: Grounded circuit. Faulty EOT sensor. Faulty Powertrain Control Module (PCM). Turn ignition off. Disconnect EOT sensor connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Repeat «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If DTC P0198 is present, replace EOT sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P0198 is not present, go to next step.
5. 5) Check For Short To Ground Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 38 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 10,000 ohms or less, locate and repair short to ground in EOT sensor circuit. Clear DTCs and repeat QUICK TEST.
6. 6) Continuous Memory DTC P0197 Or P0198: Check Sensor DTC P0197 indicates EOT sensor is out of self-test range (low). DTC P0198 indicates EOT sensor is out of self-test range (high). Possible causes for these faults are: Grounded circuit. Faulty EOT sensor. Faulty Powertrain Control Module (PCM). Turn ignition off. Using scan tool, access EOT PID from PID/DATA monitor menu. Observe EOT PID reading and tap on EOT sensor to simulate road shock. Wiggle EOT wiring harness connector. If EOT PID reading switches to 212°F (100°C), go to step 9). If EOT PID reading does not switch to 212°F (100°C), go to next step.
7. 7) Check Wiring Harness Again, access EOT PID from PID/DATA monitor menu. Observe EOT PID reading and wiggle wiring harness starting at EOT sensor and working toward PCM. If EOT PID reading switches to 212°F (100°C), locate and repair intermittent in wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If EOT PID reading does not switch to 212°F (100°C), go to next step.
8. 8) Check PCM Connector Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If connector is okay, no problem is indicated at this time. Clear DTCs and repeat QUICK TEST.
9. 9) Inspect EOT Connector Disconnect and inspect EOT sensor connector for damaged pins, corrosion and loose wires. Repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If connector is okay, replace EOT sensor. Clear DTCs and repeat QUICK TEST.
10. 10) DTC P0196 Or P1184 These DTCs indicate engine oil temperature is not warm enough to perform KOER CYLINDER CONTRIBUTION SELF-TEST. Possible causes for this fault are: Engine not normal operating temperature. Low oil level. Faulty cooling system. Faulty EOT sensor. Faulty EOT sensor circuit. Verify no KOEO DTCs are present. Drive vehicle or operate engine until engine is at normal operating temperature. Perform «KOER CYLINDER CONTRIBUTION SELF-TEST»(ref-24260-S30581755912001010400000) . If DTC P0196 or P1184 is present, go to next step. If DTC P0196 or P1184 is not present, repair other DTCs that are present. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
11. 11) Check EOT Sensor Turn ignition on. Using scan tool, access EOT PID from PID/DATA monitor menu. While observing scan tool, tap on sensor to simulate road shock. Wiggle sensor connector. If PID value does not fluctuate or does not change to less than 165°F (74°C), go to next step. If PID value fluctuates or changes to less than 165°F (74°C), replace EOT sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
12. 12) Check Wiring Harness While observing EOT PID, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (PID value fluctuates), isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no fault is found, go to next step.
13. 13) Inspect PCM & EOT Sensor Wiring Harness Connectors Turn ignition off. Disconnect PCM 104-pin connector and EOT sensor connector. Inspect connectors for damaged pins, corrosion and loose wires. If connectors and terminals are damaged, repair as necessary and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If connectors and terminals are okay, fault cannot be duplicated at this time and testing is complete.

Perform this test when directed by QUICK TEST. ICP sensor's primary function is to provide a feedback signal to indicate fuel rail pressure. PCM uses this signal to correct injector timing and pulse width.

Identifying Injection Control Pressure (ICP) Sensor Circuit & Connector Terminals. Scheme 304

1. 1) DTC P1280: Low ICP Circuit Input This DTC indicates injector control signal is out of self-test range (low). Possible causes for this fault are: Biased ICP sensor/PCM. Open ICP sensor circuit. Open VREF circuit. Shorted ICP sensor circuit. Faulty Powertrain Control Module (PCM). Disconnect ICP sensor connector. Turn ignition on. Measure voltage between ground and Brown/White wire (VREF circuit) at ICP sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, locate and repair open circuit in Brown/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
2. 2) Check SIG RTN Circuit Measure voltage between Brown/White wire and Gray/Red wire at ICP sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, locate and repair open circuit in Gray/Red wire (SIG RTN circuit). Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
3. 3) Check ICP Signal Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Light Blue/Red wire at ICP wiring harness connector and test pin No. 87 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check VREF Circuit Measure resistance between Brown/White wire at ICP sensor wiring harness connector and test pin No. 90 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Brown/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 5) Check SIG RTN Circuit Measure resistance between Gray/Red wire at ICP sensor wiring harness connector and test pin No. 91 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 6) Check For Short To Ground Measure resistance between test pin No. 87 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground in Light Blue/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check For Short Connect PCM connector to breakout box. Measure resistance between test pin No. 87 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, replace ICP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 10,000 ohms or less, replace PCM. Clear DTCs and repeat QUICK TEST.
8. 8) DTC P1281: High ICP Circuit Input This DTC indicates injector control signal is out of self-test range (high). Possible causes for this fault are: Biased ICP sensor/PCM. Shorted ICP sensor circuit. Faulty Powertrain Control Module (PCM). Disconnect ICP sensor connector. Turn ignition on. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1280 is present, replace ICP sensor. Clear DTCs and repeat QUICK TEST. If DTC P1280 is not present, go to next step.
9. 9) Check For Short To Power Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 87 and test pins No. 55, 71, 90 and 97 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to power in Light Blue/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
10. 10) Check For Short Connect PCM connector to breakout box. Measure resistance between test pin No. 87 and test pins No. 55, 71, 90 and 97 at breakout box. If all readings are more than 10,000 ohms, replace ICP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 10,000 ohms or less, replace PCM. Clear DTCs and repeat QUICK TEST.
11. 11) KOEO DTC P1210 Or P1212: These DTCs indicate injector control signal is greater than expected. Possible causes for this fault are: Biased ICP sensor. Shorted ICP sensor circuit. Open ICP SIG RTN circuit. Faulty Powertrain Control Module (PCM). Turn ignition off. Disconnect ICP sensor connector. Measure resistance between ground and Gray/Red wire at ICP sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair short to ground in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
12. 12) Check For Short To Power Turn ignition on. Measure voltage between ground and Light Blue/Red wire at ICP sensor wiring harness connector. If voltage is less than .25 volt, go to next step. If voltage is .25 volt or more, locate and repair short to power in ICP signal circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
13. 13) Check ICP Sensor Turn ignition off. Reconnect ICP sensor connector. Turn ignition on. Using scan tool, select ICP PID from PID/DATA monitor menu. If ICP PID reading indicates zero psi, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If ICP PID reading does not indicate zero psi, replace ICP sensor. Clear DTCs and repeat QUICK TEST.
14. 14) Continuous Memory DTC P1212 This DTC indicates that there was no ICP signal present during cranking. Possible causes for this fault are: Empty/low oil reservoir. Injection Pressure Regulator (IPR) circuit fault. Faulty IPR valve. Faulty ICP sensor. Faulty high pressure pump. If any KOEO DTCs are present, service DTCs as necessary before continuing with this test. If DTC P1212 is still present, go to next step. If no KOEO DTCs are present, go to next step. NOTE: If vehicle stalls after start and reservoir empties, oil is not being supplied from low oil pressure system.
15. 15) Check Oil Reservoir Level Remove plug in top of oil reservoir and check level. If oil level is not within 1" (25.4 mm), check and repair cause of low fluid. Top off fluid. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If oil level is within 1" (25.4 mm), check fuel pressure. See TANDEM FUEL PUMP PRESSURE TEST under HARD START/NO-START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article. Repair as necessary. If fuel pressure is okay, check PID values while cranking engine. See CHECK PARAMETER IDENTIFICATION (PID) DURING CRANKING under HARD START/NO-START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article. Repair as necessary. If PID values are okay, clear DTCs. Using scan tool, select ICP V PID from PID/DATA monitor menu. Crank engine for 5 seconds and observe scan tool. If ICP V PID voltage is .85 volt or more, fault is intermittent. Go to step 19). If ICP V PID voltage is less than .85 volt, go to next step.
16. 16) Check Injection Control Pressure (ICP) Sensor Disconnect ICP sensor connector. Attempt to start vehicle. If vehicle starts, replace ICP sensor and retest. If vehicle does not start, go to next step.
17. 17) Check Oil System Pressure Perform INJECTION CONTROL PRESSURE TEST and check for pressurized oil leaks. See HARD START/NO-START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article. Repair as necessary. If no leaks are found, go to next step.
18. 18) Check Injection Pressure Regulator (IPR) Valve Reconnect all hoses and ICP sensor connector. Replace IPR valve. Ensure oil reservoir level is full. Attempt to start vehicle. If vehicle starts, replacing IPR valve corrected fault. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If vehicle does not start, replace high pressure oil pump. Clear DTCs and repeat QUICK TEST.
19. 19) Check For Intermittent Faults Turn ignition on. Using scan tool, select ICP PID from PID/DATA monitor menu. While observing ICP PID, wiggle and bend small sections of wiring harness starting at ICP sensor and working toward PCM. If ICP PID reading fluctuates, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If ICP PID does not fluctuate, go to next step.
20. 20) Check Injection Pressure Regulator (IPR) Circuit Inspect wiring harness and connectors between IPR valve and PCM. Repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If wiring harness and connectors are okay, no problem is indicated at this time. Clear DTCs and repeat QUICK TEST.
21. 21) DTC P1284 This DTC indicates a ICP sensor circuit failure has occurred while performing KOER CYLINDER CONTRIBUTION SELF-TEST. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If a ICP circuit fault is indicated, go to appropriate circuit test and service DTC as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If no ICP fault is indicated, replace PCM. Clear DTC, and repeat QUICK TEST.
22. 22) Continuous Memory DTC P1210 This DTC indicates ICP signal voltage was too high during normal driving conditions. Possible causes for this fault are: Biased ICP sensor. Injection Control Pressure (ICP) circuit fault. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If any KOEO DTCs are present, service DTCs as necessary before continuing with this test. If DTC P1210 is still present, go to next step. If no DTCs are present, fault is intermittent. Go to next step.
23. 23) Check ICP Signal Ground Circuit Turn ignition off. Disconnect ICP sensor connector. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Connect DVOM between test pin No. 91 at breakout box and Gray/Red wire at ICP sensor wiring harness connector. Set DVOM to ohms scale. While observing DVOM, wiggle and bend small sections of wiring harness starting at ICP sensor and working toward PCM. If resistance stays at less than 5 ohms, go to next step. If resistance changes to 5 ohms or more, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
24. 24) Check ICP Signal Circuit For Short To Power Measure voltage between ground and test pin No. 87 at breakout box. No voltage should be present. While observing DVOM, wiggle and bend small sections of wiring harness starting at ICP sensor and working toward PCM. If no voltage is present, go to next step. If any voltage is indicated, repair intermittent short to power. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
25. 25) Check ICP Sensor Circuit Turn ignition off. Reconnect ICP sensor connector. Remove breakout box and reconnect PCM 104-pin connector to PCM. Clear DTCs. Turn ignition on. Lightly tap on ICP sensor. Check for DTCs. If DTC P1210 is present, replace ICP sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1210 is not present, fault cannot be duplicated at this time and testing is complete.

Perform this test when directed by QUICK TEST. IVS provides PCM with a signal to verify when accelerator pedal is in idle position.

Idle Validation Switch Circuit & Connector Terminals. Scheme 305

1. 1) DTC P0221 Or P0220 This DTC indicates a malfunction has occurred in Idle Validation Switch (IVS) circuit. Possible causes for this fault are: Faulty accelerator pedal assembly. Open circuit. Short to power in IVS circuit. Faulty Powertrain Control Module (PCM). Turn ignition off. Ensure scan tester is connected to Data Link Connector (DLC). Turn ignition on. Using scan tester, access AP and IVS PID from PID/DATA monitor menu. With accelerator pedal in the up position, if IVS PID reading indicates ON, go to step 10). If IVS PID reading does not indicate ON, go to next step.
2. 2) Check IVS Transition Voltage Observe AP (voltage) and IVS (state) PID reading and slowly depress accelerator pedal. If IVS PID reading switches to ON at .4-1.6 volts, replace accelerator pedal assembly. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If IVS PID does not switch to ON at .4-1.6 volts, go to next step.
3. 3) Check IVS Observe IVS PID reading and fully depress accelerator pedal. If IVS PID reading switches to ON at any time, replace accelerator pedal assembly. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If IVS PID does not switch to ON at any time, go to next step.
4. 4) Check IVS Resistance Disconnect IVS and inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. With accelerator pedal depressed, measure resistance between IVS terminals. If resistance is less than 5 ohms, go to step 8). If resistance is 5 ohms or more, replace accelerator assembly. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 4) to step 6). No test procedures have been omitted.
5. 6) Check Circuit No. 16 Remove fuse No. 17 at power distribution box in engine compartment. Measure resistance between non-powered side of No. 17 fuse holder (Yellow wire) and power side of No. 3 fuse holder (Red/Light Green wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit between fuse holders. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 7) Check Circuit No. 276 Turn ignition off. Measure resistance of Brown wire between non-powered side of No. 3 fuse holder and IVS wiring harness connector. If resistance is less than 5 ohms, go to step 9). If resistance is 5 ohms or more, locate and repair open circuit in Brown wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 8) Check Circuit No. 16 Resistance Turn ignition off. Ensure IVS is disconnected. Remove fuse No. 8 from power distribution box in engine compartment. Measure resistance of Red/Light Green wire between non-powered side of No. 8 fuse holder and IVS wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Red/Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
8. 9) Check Circuit No. 308 Resistance Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Red/Orange wire at IVS wiring harness connector and test pin No. 10 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear memory, and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 5 ohms or more, locate and repair open circuit in Red/Orange wire. Clear DTCs and repeat QUICK TEST.
9. 10) Check For Short To Power Disconnect IVS connector. If IVS PID reading indicates OFF, replace accelerator pedal assembly. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If IVS PID does not indicate OFF, locate and repair short to power in Red/Orange wire between PCM and IVS wiring harness connector. Clear DTCs and repeat QUICK TEST.

Perform this test when directed by QUICK TEST. Injector Driver Module (IDM) is capable of detecting individual injector open and shorts to either ground or power while engine is running. IDM is also capable of detecting right or left bank high side circuit opens or shorts to ground.

Injector Driver Module (IDM) Circuit & Connector Terminals. Scheme 306

Engine Wiring Harness 42-Pin Connector Terminals. Scheme 307

Note. Each valve cover gasket has 2 fuel injector connectors that are part of the gasket. Each connector is responsible for 2 fuel injectors. If connector is faulty, replace valve cover gasket.

1. 1) DTC P0261, P0264, P0267, P0270, P0273, P0276, P0279 Or P0282 These DTCs indicate a short to ground between Injector Driver Module (IDM) and injector. For DTC and related circuit identification, see INJECTOR DTCS P0261-P0282 CIRCUIT IDENTIFICATION table. INJECTOR DTCS P0261-P0282 CIRCUIT IDENTIFICATION Cylinder No. DTC Circuit No. (Wire Color) 1 P0261 555 (TAN) 2 P0264 556 (WHT) 3 P0267 557 (BRN/YEL 4 P0270 558 (BRN/LT BLU) 5 P0273 559 (TAN/BLK) 6 P0276 560 (LT GRN/ORG) 7 P0279 561 (TAN/RED) 8 P0282 562 (LT BLU) Turn ignition off. Disconnect suspect injector connector at valve cover gasket. Measure resistance between ground and suspect circuit terminal at engine wiring harness 42-pin connector. Connector is located in left rear corner of engine compartment, behind engine. See «INJECTOR DTCS P0261-P0282 CIRCUIT IDENTIFICATION»(ref-24260-S37332511032001010400000) table. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, go to step 4).
2. 2) Check For Short To Ground Install Glow Plug Injector Adapter (014-00935) to injector connector at valve cover gasket. Measure resistance between ground and suspect circuit at glow plug injector adapter. If resistance is more than 10,000 ohms, fault may be intermittent. Go to step 5). If resistance is 10,000 ohms or less, go to next step.
3. 3) Inspect Wiring Harness For Short Remove valve cover. Disconnect suspect injector connector. Inspect Under Valve Cover (UVC) wiring harness for a short to ground. Replace wiring harness as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If wiring harness is okay, replace injector. Clear DTCs and repeat QUICK TEST.
4. 4) Check For Short Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Measure resistance at IDM wiring harness connector between suspect injector circuit terminal, and all other circuits of IDM connector and to ground. If all readings are more than 10,000 ohms, replace IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If any reading is 10,000 ohms or less, locate and repair short between injector connector at valve cover and IDM connector. Clear DTCs and repeat QUICK TEST.
5. 5) Check For Intermittent Short To Ground Turn ignition off. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Reconnect all other connectors. Connect DVOM between ground and suspect injector circuit terminal at IDM wiring harness connector. While observing DVOM, wiggle and bend small sections of wiring harness starting at suspect injector connector and working toward IDM. If resistance changes to less than 10,000 ohms at any time, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance does not change to less than 10,000 ohms, replace IDM. Clear DTCs and repeat QUICK TEST. Diagnostic Aids Injector Driver Module (IDM) has 2 output functions, high side driver output and low side driver output. High side driver output distributes voltage to proper cylinder bank based on Cylinder Identification (CID) and provides regulated current to unit injectors. This is based on Fuel Delivery Command Signal (FDCS) from IDM internal 115-volt supply. Injection timing and duration is commanded by PCM. Low side driver output controls sequencing (firing order) of engine based on CID and FDCS inputs. INJECTOR DTC & CIRCUIT IDENTIFICATION Cyl DTC Low Side Circuit (Wire Color) High Side Circuit (Wire Color) 1 P1261-P0262 555 (TAN) 1087 (ORG) 2 P1262-P0265 556 (WHT) 878 (PNK/YEL) 3 P1263-P0268 557 (BRN/YEL) 1087 (ORG) 4 P1264-P0271 558 (BRN/LT BLU) 878 (PNK/YEL) 5 P1265-P0274 559 (TAN/BLK) 1087 (ORG) 6 P1266-P0277 560 (LT GRN/ORG) 878 (PNK/YEL) 7 P1267-P0280 561 (TAN/RED) 1087 (ORG) 8 P1268-P0283 562 (LT BLU) 878 (PNK/YEL) NOTE: Each valve cover gasket has 2 fuel injector connectors that are part of the gasket. Each connector is responsible for 2 fuel injectors. If connector is faulty, replace valve cover gasket.
6. 6) DTC P0262, P0265, P0268, P0271, P0274, P0277, P0280, P0283 Or P1261-P1268 These DTCs indicate that low side circuit is shorted to power or high side circuit is shorted between IDM and fuel injector. Identify DTC, and use «INJECTOR DTC & CIRCUIT IDENTIFICATION»(ref-24260-S11299018362001010400000) table and (Scheme 306) - (Scheme 307) to determine which circuit to check. Turn ignition on. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Disconnect suspect injector connector at valve cover gasket. Also, disconnect remaining injector connector on same cylinder bank. Measure resistance between positive battery terminal and low side circuit terminal at suspect injector connector at valve cover gasket. Also, measure resistance between positive battery terminal and high side circuit terminal at suspect injector connector at valve cover gasket connector. If both readings are less than 10,000 ohms, go to next step. If any reading is 10,000 ohms or more, locate and repair short to power in suspect circuit between IDM and injector connector at valve cover gasket. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
7. 7) Check For Short To Injector Cover Install Glow Plug Injector Adapter (014-00935) to injector connector at valve cover gasket. Measure resistance between high side and low side circuit terminals at glow plug injector adapter. If resistance is less than 2 ohms (engine cold), go to next step. If resistance is 2 ohms or more, fault may be intermittent. Go to step 10).
8. 8) Check For Short Remove valve cover. Disconnect suspect injector connector. Measure resistance of both high and low side circuits between glow plug injector adapter and suspect injector connector. If both readings are more than 10,000 ohms, replace injector. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If any reading is 10,000 ohms or less, go to next step.
9. 9) Check Wiring Harness Remove Under Valve Cover (UVC) wiring harness. Measure resistance between low side and high side circuits at valve cover gasket wiring harness. If resistance is less than 5 ohms, replace gasket wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance is 5 ohms or more, replace UVC wiring harness. Clear DTCs and repeat QUICK TEST.
10. 10) Check For Intermittent Short To Power Turn ignition off. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Disconnect all 4 injector connectors at valve cover gaskets. Connect DVOM between positive battery terminal and suspect injector low side circuit terminal at IDM wiring harness connector. While observing DVOM, wiggle and bend small sections of wiring harness starting at suspect injector connector and working toward IDM. Repeat wiggle test for suspect injector high side circuit. If resistance changes to less than 10,000 ohms at any time, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance does not change to less than 10,000 ohms, replace IDM. Clear DTCs and repeat QUICK TEST. NOTE: Each valve cover gasket has 2 fuel injector connectors that are part of the gasket. Each connector is responsible for 2 fuel injectors. If connector is faulty, replace valve cover gasket.
11. 11) DTC P1271-P1278: Check For Open Circuit These DTCs indicate an open in low side circuit or high side circuit between IDM and fuel injector. Identify DTC and use INJECTOR DTC P1271-P1278 CIRCUIT IDENTIFICATION table and (Scheme 306) - (Scheme 307) to determine which circuit to check. Turn ignition off. Disconnect suspect injector connector at valve cover gasket. Install Glow Plug Injector Adapter (014-00935) to injector connector at valve cover gasket. Measure resistance between high side and low side circuit terminals at glow plug injector adapter. If resistance is less than 5 ohms, go to step 13). If resistance is 5 ohms or more, go to next step. INJECTOR DTC P1271-P1278 CIRCUIT IDENTIFICATION Cyl DTC Low Side Circuit (Wire Color) High Side Circuit (Wire Color) 1 (1) P1271 555 (TAN) 1087 (ORG) 2 (2) P1272 556 (WHT) 878 (PNK/YEL) 3 (1) P1273 557 (BRN/YEL) 1087 (ORG) 4 (2) P1274 558 (BRN/LT BLU) 878 (PNK/YEL) 5 (1) P1275 559 (TAN/BLK) 1087 (ORG) 6 (2) P1276 560 (LT GRN/ORG) 878 (PNK/YEL) 7 (1) P1277 561 (TAN/RED) 1087 (ORG) 8 (2) P1278 562 (LT BLU) 878 (PNK/YEL) (1) Right cylinder head. (2) Left cylinder head.
12. 12) Check For Open In Injector Remove valve cover. Disconnect suspect injector connector. Measure resistance of high side circuit between injector connector and glow plug injector adapter. Also, measure resistance of low side circuit between injector connector and glow plug injector adapter. If both readings are less than 5 ohms, replace injector. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If any reading is 5 ohms or more, go to step 23).
13. 13) Check For Open In Low Side Circuit Disconnect Injector Driver Module (IDM) 40-pin connector. IDM is located in left side of engine compartment. Measure resistance of suspect low side circuit between wiring harness side of injector connector at valve cover gasket and IDM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in low side circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
14. 14) Check For Open In High Side Circuit Measure resistance of suspect high side circuit between wiring harness side of injector connector at valve cover gasket and IDM connector. If resistance is less than 5 ohms, fault may be intermittent. Go to next step. If resistance is 5 ohms or more, repair open in high side circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
15. 15) Check For Intermittent Open Injector Circuit Ensure IDM is disconnected. Reconnect all other connectors. Connect DVOM between suspect injector low side circuit terminal and high side circuit terminal at IDM wiring harness connector. While observing DVOM, wiggle and bend small sections of wiring harness starting at suspect injector connector and working toward IDM. If resistance changes to more than 5 ohms at any time, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance does not change to more than 5 ohms, replace IDM. Clear DTCs and repeat QUICK TEST. NOTE: Each valve cover gasket has 2 fuel injector connectors that are part of the gasket. Each connector is responsible for 2 fuel injectors. If connector is faulty, replace valve cover gasket.
16. 16) DTC P1291 Or P1292: Check For Short In High Side Circuit These DTCs indicate a short to ground or short to power in high side circuit between IDM and fuel injector. Identify DTC and use INJECTOR DTC P1291 OR P1292 CIRCUIT IDENTIFICATION table and (Scheme 306) - (Scheme 307) to determine which circuit to check. Turn ignition off. Disconnect Injector Driver Module (IDM) 40-pin connector. IDM is located in left side of engine compartment. Measure resistance between ground and suspect high side circuit terminal at IDM wiring harness connector. If resistance is more than 10,000 ohms, go to step 18). If resistance is 10,000 ohms or less, go to next step. INJECTOR DTC P1291 OR P1292 CIRCUIT IDENTIFICATION DTC Circuit No. (Wire Color) Bank P1291 1087 (ORG) Right P1292 878 (PNK/YEL) Left
17. 17) Check For Short To Ground In High Side Circuit Disconnect both injector connectors at appropriate valve cover gasket (bank with DTC). Measure resistance between ground and suspect high side circuit terminal at IDM wiring harness connector. If resistance is more than 10,000 ohms, go to step 2). If resistance is 10,000 ohms or less, locate and repair short to ground between IDM connector and injector connector. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
18. 18) Check For Short To Power In High Side Circuit Turn ignition on. Measure resistance between positive battery terminal and suspect high side circuit terminal at IDM wiring harness connector. Also, measure resistance between positive battery terminal and other high side circuit terminal at IDM wiring harness connector. If both readings are more than 10,000 ohms, fault may be intermittent. Go to next step. If any reading is 10,000 ohms or less, repair short to power in high side circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
19. 19) Check For Intermittent Short To Power Ensure IDM is disconnected and ignition is on. Connect DVOM between positive battery terminal and suspect injector high side circuit terminal at IDM wiring harness connector. While observing DVOM, wiggle and bend small sections of wiring harness starting at suspect injector connector and working toward IDM. Repeat wiggle test for other injector high side circuit. If resistance changes to less than 10,000 ohms at anytime, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance does not change to less than 10,000 ohms, replace IDM. Clear DTCs and repeat QUICK TEST. NOTE: Each valve cover gasket has 2 fuel injector connectors that are part of the gasket. Each connector is responsible for 2 fuel injectors. If connector is faulty, replace valve cover gasket.
20. 20) DTC P1293-P1294: Check High Side Circuit These DTCs indicate an open in high side circuit between IDM and fuel injector. Identify DTC and use INJECTOR DTC P1293 OR P1294 CIRCUIT IDENTIFICATION table and (Scheme 306) - (Scheme 307) to determine which circuit to check. Turn ignition off. Disconnect both injector connectors at appropriate valve cover gasket (bank with DTC). Turn ignition on. Measure voltage of high side circuit between ground terminal "C" at injector connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 24). INJECTOR DTC P1293 OR P1294 CIRCUIT IDENTIFICATION DTC Circuit No. (Wire Color) Bank P1293 878 (PNK/YEL) Left P1294 1087 (ORG) Right
21. 21) Check Injector Resistance Turn ignition off. Install Glow Plug Injector Adapter (014-00935) to suspect injector connector at valve cover gasket. Measure resistance between high side and low side circuit terminals at glow plug injector adapter. If resistance is less than 5 ohms, fault may be intermittent. Go to step 15). If resistance is 5 ohms or more, go to next step.
22. 22) Check For Open In Wiring Harness Remove valve cover. Disconnect suspect injector connector. Measure resistance between injector connector and exterior valve cover gasket connector. If resistance is less than 5 ohms, replace injector. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance is 5 ohms or more, go to next step.
23. 23) Determine Wiring Fault Disconnect Under Valve Cover (UVC) wiring harness from connector at valve cover gasket. Measure resistance between each terminal in valve cover gasket connector. If all readings are less than 5 ohms, connector is okay. Replace UVC wiring harness. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If any reading is 5 ohms or more, an open circuit exists in connector. Replace valve gasket. Clear DTCs and repeat QUICK TEST.
24. 24) Check For Open Circuit Turn ignition off. Disconnect Injector Driver Module (IDM) 40-pin connector. IDM is located on left side of engine compartment. Ensure both injector connectors are disconnected at appropriate valve cover gasket. Measure resistance of suspect high side circuit between IDM wiring harness connector and terminal "C" at both suspect injector connectors. If all readings are less than 5 ohms, fault may be intermittent. Go to step 15). If any reading is 5 ohms or more, locate and repair open in high side circuit. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). NOTE: Each valve cover gasket has 2 fuel injector connectors that are part of the gasket. Each connector is responsible for 2 fuel injectors. If connector is faulty, replace valve cover gasket.
25. 25) DTC P0263, P0266, P0269, P0272, P0275, P0278, P0281 Or P0301-P0308: Cylinder Non-Contributing These DTCs indicate a cylinder is not contributing equally during KOER CYLINDER CONTRIBUTION SELF-TEST. Possible causes for this fault are: Broken compression rings. Faulty injector assembly. Leaking or bent valve. Bent push rod. Broken rocker arm bolts. Bent connecting rod. NOTE: Each cylinder is tested in numerical sequence (1-8) and does not always set a DTC. It may be necessary to perform KOER CYLINDER CONTRIBUTION SELF-TEST 3 or 4 times to verify that a non-contributing cylinder is constantly same cylinder. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000), «KOER CYLINDER CONTRIBUTION SELF-TEST»(ref-24260-S30581755912001010400000) and «CONTINUOUS MEMORY SELF-TEST»(ref-24260-S00805902012001010400000). Record any DTCs. If any DTCs are set, service DTCs as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If no DTCs are set, go to next step. CYLINDER CONTRIBUTION DTC IDENTIFICATION KOER DTC Continuous Memory DTC Cylinder No. P0263 P0301 1 P0266 P0302 2 P0269 P0303 3 P0272 P0304 4 P0275 P0305 5 P0266 P0306 6 P0281 P0307 7 P0284 P0308 8
26. 26) Cylinder Non-Contributing Perform TANDEM FUEL PUMP PRESSURE, AIR IN FUEL SYSTEM, INJECTOR CONTROL PRESSURE TESTS and CRANKCASE PRESSURE TEST. See ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article. Repair as necessary. If no problems are found, check engine mechanical condition. Repair as necessary. If engine mechanical condition is okay, replace injector assembly. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
27. 27) DTC P1297: Injector High Side Circuit Short Turn ignition off. Disconnect Injector Driver Module (IDM) 40-pin connector. IDM is located in left side of engine compartment. Measure resistance between both high side circuit terminals (No. 23 and 24) at IDM wiring harness connector. (Scheme 306) If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, locate and repair short between high side circuits. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
28. 28) Check For Intermittent Between High Side Circuits Turn ignition off. Connect DVOM between both high side circuit terminals (No. 23 and 34) at IDM wiring harness connector. While observing DVOM, wiggle and bend small sections of wiring harness starting at IDM connector and working toward injector connectors. If resistance changes to less than 10,000 ohms at any time, isolate fault and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000). If resistance does not change to less than 10,000 ohms, replace IDM. Clear DTCs and repeat QUICK TEST. NOTE: Each valve cover gasket has 2 fuel injector connectors that are part of the gasket. Each connector is responsible for 2 fuel injectors. If connector is faulty, replace valve cover gasket.
29. 29) DTC P1295 Or P1926: Check For Short To Ground These DTCs indicate that more than one fault exists on right or left cylinder bank. A short and open on both low side and high side circuits could exist on bank with DTC. DTC P1295 OR P1296 IDENTIFICATION DTC Bank P1295 Right P1296 Left Turn ignition off. Disconnect Injector Driver Module (IDM) 40-pin connector. IDM is located in left side of engine compartment. Measure resistance between ground and each injector circuit terminal at IDM wiring harness connector. (Scheme 306) If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, perform the following: If low side circuit short to ground was found, go to step 1). Repair short then return to this step. If high side circuit short to ground was found, go to step 16). Repair short then return to this step. NOTE: Injector low side circuits are circuit No. 555, 556, 557, 558, 559, 560, 561 and 562. Injector high side circuits are circuit No. 878 and 1087. (Scheme 306)
30. 30) Check For Short To Power Turn ignition on. Measure voltage between ground and each injector circuit terminal at IDM wiring harness connector. If voltage is present at any circuit, go to next step. If voltage is not present at any circuit, perform the following: If low side circuit short to power was found, go to step 6). Repair short and then return to this step. If high side circuit short to power was found, go to step 16). Repair short and then return to this step.
31. 31) Check For Short Turn ignition off. Measure resistance between high side circuit terminals (No. 23 and 24) at IDM wiring harness connectors. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short between high side circuits. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).
32. 32) Check For Open Circuit Disconnect all 4 injector connectors at valve cover gaskets. Measure resistance of each injector circuit between valve cover gasket connector and IDM wiring harness connector. If all readings are less than 10,000 ohms, go to next step. If any reading is 10,000 ohms or more, repair open in appropriate circuit.
33. 33) Check For Open Circuit Under Valve Cover Install Glow Plug Injector Adapter (014-00935) to valve cover gasket injector connector. Using glow plug injector adapter, measure resistance of each injector circuit through valve cover. (Scheme 306) If any reading is more than 5 ohms, go to step 12). If all readings are 5 ohms or less, reconnect all connectors. Clear DTCs and repeat «KOEO INJECTOR ELECTRICAL SELF-TEST»(ref-24260-S09777461152001010400000) and «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000). If DTC P1295 or P1296 resets, replace IDM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000).

Perform this test when directed by QUICK TEST. A BARO sensor that is detected out of range (high or low) by PCM will cause the PCM to ignore BARO sensor signal and use Manifold Absolute Pressure (MAP) sensor signal as an indication of barometric pressure.

Identifying Barometric Pressure (BARO) Sensor Circuit & Connector Terminals. Scheme 308

1. 1) DTC P0107: BARO Circuit Low Input This DTC indicates BARO sensor circuit low input was detected during KOEO ON-DEMAND SELF-TEST or during continuous diagnostic monitoring. Possible causes for this DTC are: Biased BARO sensor/PCM. Open BARO or VREF sensor circuit. Shorted SIG RTN or PWR GND circuit. Faulty PCM. Turn ignition off. Disconnect BARO sensor connector. Sensor is located behind left side of instrument panel. Turn ignition on. Measure voltage between ground and Brown/White wire at BARO sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, locate and repair open circuit in Brown/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
2. 2) Check SIG RTN Circuit Measure voltage between Gray/Red wire and Brown/White wire at BARO sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
3. 3) Check BARO Signal Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Dark Blue/Light Green wire at BARO sensor wiring harness connector and test pin No. 63 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Dark Blue/Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check VREF Circuit Measure resistance between Brown/White wire at BARO sensor wiring harness connector and test pin No. 90 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Brown/White wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 5) Check SIG RTN Circuit Measure resistance between Gray/Red wire at BARO sensor wiring harness connector and test pin No. 91 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 6) Check For Grounded Signal Circuit Measure resistance between test pin No. 63 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground in Dark Blue/Light Green wire (BARO signal circuit). Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check For Grounded Signal Circuit Connect PCM connector to breakout box. Measure resistance between test pin No. 63 and test pins No. 25, 51, 76, 77, 91 and 103 at breakout box. If all readings are more than 10,000 ohms, replace BARO sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 10,000 ohms or less, replace PCM. Clear DTCs and repeat QUICK TEST.
8. 8) DTC P0108 This DTC indicates BARO sensor circuit high input was detected during «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) or during continuous diagnostic monitoring. Possible causes for this fault are: Biased BARO sensor/PCM. BARO sensor circuit shorted to VREF circuit. Faulty PCM. Turn ignition on. Disconnect BARO sensor connector. Sensor is located behind left side of instrument panel. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If DTC P0107 is present, replace BARO sensor. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P0107 is not present, go to next step.
9. 9) Check For Short To Power Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 63 and test pins No. 55, 71, 90 and 97 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 10,000 ohms or less, locate and repair short to power in Dark Blue/Light Green wire. Clear DTCs and repeat QUICK TEST.

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose

1. 4x4 low switch.
2. Wiring harness circuits for 4x4 low switch.
3. Powertrain Control Module (PCM).

Identifying 4x4 Low Switch Circuit & Connector Terminals. Scheme 309

1. 1) DTC P1729 Or P1781: Perform Switch Functional Check Turn ignition on. Observe 4x4L indicator and switch to and from 4x4L. If indicator light agrees with lever position, go to next step. If indicator light does not agree with lever position, go to step 4).
2. 2) Check 4x4L Parameter Identification (PID) Using scan tool, access 4x4L PID from PID/DATA monitor menu. Observe 4x4L PID reading and switch to and from 4x4L. If 4x4L PID reading agrees with lever position, go to next step. If 4x4L PID reading does not agree with lever position, go to step 11).
3. 3) Check For Intermittent While observing 4x4L PID, wiggle and bend all wiring harness circuits for 4x4L. If 4x4L PID switched states (on/off) at any time, isolate fault and repair as necessary. Reconnect all connectors. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If 4x4L PID did not switch states, no problem is indicated at this time. Clear DTCs and repeat QUICK TEST.
4. 4) Check Voltage At Switch Disconnect 4x4L switch 2-pin connector. Switch is located on front of transfer case. Measure voltage between ground and Light Blue/Black wire at 4x4L switch wiring harness connector. If battery voltage is present, replace 4x4L switch. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If battery voltage is not present, go to next step.
5. 5) Check Indicator Light Observe 4x4L indicator light and shift to and from 4x4L. If indicator light always stays on, locate and repair short to ground between indicator light and switch connector. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If indicator light does not always stay on, go to next step.
6. 6) Check Voltage At Fuse Measure voltage between ground and both sides of fuse No. 17 at instrument panel fuse block. If battery voltage is present at both sides of fuse, go to step 9). If battery voltage is not present at both sides of fuse, go to next step.
7. 7) Check Power Feed To Fuse Measure voltage between ground and power side of No. 17 fuse holder (Red/Light Green wire). If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in Red/Light Green wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
8. 8) Check For Short To Ground Ensure 4x4 lever is not in LOW position. Turn ignition off. Measure resistance between ground and non-powered side of No. 17 fuse holder (Red/Yellow wire). If resistance is more than 10,000 ohms, replace fuse. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 10,000 ohms or less, locate and repair short to ground in Red/Yellow wire.
9. 9) Check 4x4L Bulb Turn ignition off. Remove and inspect 4x4L indicator bulb. Replace bulb as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If bulb is okay, go to next step.
10. 10) Check Voltage At Indicator Bulb Turn ignition on. Shift out of 4x4 Low. Measure voltage between ground and Red/Yellow wire at indicator bulb socket. If battery voltage is present, locate and repair open circuit in Light Blue/Black wire between indicator bulb and 4x4L switch. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If battery voltage is not present, locate and repair open circuit in Red/Yellow wire between fuse and indicator bulb. Clear DTCs and repeat QUICK TEST.
11. 11) Check Circuit No. 784 Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect 4x4L switch connector. Measure resistance between Light Blue/Black wire at 4x4L switch wiring harness connector and test pin No. 14 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Light Blue/Black wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
12. 12) Check For Short To Ground Measure resistance between ground and Light Blue/Black wire at 4x4L switch wiring harness connector. If resistance is less than 10,000 ohms, locate and repair short to ground in Light Blue/Black wire. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 10,000 ohms or more, replace PCM. Clear DTCs and repeat QUICK TEST.

Perform this test when directed by QUICK TEST.

This CIRCUIT TEST is intended to diagnose

1. A/C clutch.
2. Wiring harness circuits for A/C.
3. Powertrain Control Module (PCM).

Identifying A/C Pressure Switch Circuit. Scheme 310

1. 1) DTC P1464: A/C On During KOER Cylinder Contribution Self-Test Turn A/C heater control switch off. Repeat «KOER CYLINDER CONTRIBUTION SELF-TEST»(ref-24260-S30581755912001010400000) . If DTC P1464 is set, go to next step. If DTC P1464 is not set, fault may be intermittent. Go to step 4).
2. 2) Check A/C Power Circuit For Short Turn ignition on. Disconnect A/C clutch connector. Measure voltage between ground and Black/Yellow wire at A/C clutch wiring harness connector. If battery voltage is present, locate and repair short to power. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If battery voltage is not present, go to next step.
3. 3) Check For Short To Power Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pin No. 41 at breakout box. If battery voltage is present, locate and repair short to power. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If battery voltage is not present, replace PCM. Clear DTCs and repeat QUICK TEST.
4. 4) Check For Intermittent Short To Power Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Connect DVOM between ground and test pin No. 41 at breakout box. While observing DVOM, wiggle and bend small sections of wiring harness staring at A/C clutch connector and working toward PCM. If voltage is ever present, locate and repair short to power. If voltage is never present, no problem is indicated at this time.

Perform this test when directed by QUICK TEST.

This CIRCUIT TEST is intended to diagnose

1. Standard Corporate Protocol (SCP) communication wiring harness circuits BUS (+) and BUS (-).
2. Wiring harness circuits (chassis ground, PWR GND and VBAT).
3. Powertrain Control Module (PCM).

Identifying Data Link Connector (DLC) Circuits. Scheme 311

1. 1) Verify Self-Test Method Used Verify that correct procedure was used to activate KOEO and KOER ON-DEMAND SELF-TEST for New Generation Star (NGS) scan tool. See «QUICK TEST»(ref-24260-S02984646372001010400000) under SELF-DIAGNOSTIC SYSTEM. Verify NGS scan tool on another vehicle before proceeding with this test. If correct procedure was used, go to next step. If correct procedure was not used, repeat QUICK TEST. NOTE: NGS scan tool will abort if battery voltage drops to less than 9.5 volts. If performing repeated QUICK TEST, disconnect glow plug relay to prevent battery from going dead. Relay is located on top, right side of engine. Ignore DTC P0380 while glow plug relay is disconnected.
2. 2) Check PCM Output Ensure battery is fully charged and is not the cause of communication error. Attempt to start engine. If engine starts, go to next step. If engine does not start, go to «CIRCUIT TEST B»(ref-24260-S18677802082001010400000) .
3. 3) Check B+ At Data Link Connector (DLC) Turn ignition off. Inspect DLC for damaged pins, corrosion and loose wires. Repair as necessary. Measure resistance between positive battery terminal and terminal No. 16 at DLC. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in DLC B+ circuit. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
4. 4) Check DLC Ground Circuit Turn ignition off. Measure resistance between ground and terminal No. 4 (Black wire) at DLC. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Black wire. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
5. 5) Check PWR GND Circuit Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between terminal No. 5 at DLC wiring harness connector and test pins No. 51, 76, 77 and 103 at breakout box. If all readings are less than 5 ohms, go to next step. If any reading is 5 ohms or more, locate and repair open circuit in PWR GND circuit. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
6. 6) Check BUS (-) Circuit Measure resistance between terminal No. 10 (Pink/Light Blue wire) at DLC wiring harness connector and test pin No. 15 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Pink/Light Blue wire. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
7. 7) Check For Short To Ground Measure resistance between ground and test pin No. 15 at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, locate and repair short to ground Pink/Light Blue wire (BUS (-) circuit). Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
8. 8) Check For Short To Power Turn ignition on. Measure voltage between test pin No. 15 and test pins No. 51, 76, 77 or 103 at breakout box. If voltage is more than one volt, locate and repair short to power in Pink/Light Blue wire (BUS (-) circuit). Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage is one volt or less, go to next step.
9. 9) Check DLC BUS (+) Circuit Resistance Turn ignition off. Measure resistance between terminal No. 2 (Tan/Orange wire) at DLC wiring harness connector and test pin No. 16 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Tan/Orange wire (BUS (+) circuit). Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
10. 10) Check BUS (+) Circuit For Short To Power Turn ignition on. Measure voltage between terminal No. 16 (Tan/Orange wire) at DLC wiring harness connector and test pins No. 51, 76, 77 or 103 at breakout box. If voltage is more than one volt, locate and repair short to power in Tan/Orange wire (BUS (+) circuit). Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If voltage is one volt or less, go to next step.
11. 11) Check For BUS (-) & BUS (+) Circuits Shorted Together Turn ignition off. Measure resistance between test pins No. 15 and 16 at breakout box. If resistance is more than 10,000 ohms, replace PCM. Repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If resistance is 10,000 ohms or less, locate and repair short between BUS (-) and BUS (+) circuits. Repeat QUICK TEST.

CIRCUIT TEST AM - OUTPUT CIRCUIT CHECK (OCC) HIGH

1. 1) DTC P1660 This DTC indicates that output circuit check is high. Possible causes for this fault are: High system voltage. VREF circuit fault. Faulty Powertrain Control Module (PCM). Check charging system and battery. Repair as necessary. If charging system is okay, go to next step.
2. 2) Check VREF Circuit Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pin No. 90 at breakout box. If voltage is less than .25 volt, go to next step. If voltage is .25 volt or more, locate and repair short to power in VREF circuit (Brown/White wire). Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) .
3. 3) Check PCM Reconnect PCM connector. Perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) . If DTC P1660 is still present, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1660 is not present, no problem is indicated at this time.

CIRCUIT TEST AN - OUTPUT CIRCUIT CHECK (OCC) LOW

1. 1) DTC P1661 This DTC indicates that output circuit check is low. Possible causes for this fault are: Low system voltage. VREF circuit fault. Faulty Powertrain Control Module (PCM). Check charging system and battery. Repair as necessary. If charging system is okay, go to next step.
2. 2) Check VREF Circuit
3. Disconnect Manifold Absolute Pressure (MAP) sensor connector. Turn ignition on. Measure voltage between Brown/White wire and Gray/Red wire at MAP sensor wiring harness connector. If voltage is 5 volts, go to next step. If voltage is not 5 volts, a fault exists in VREF circuit. Perform «CIRCUIT TEST B»(ref-24260-S18677802082001010400000) .
4. 3) Check VPWR Circuit Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Turn ignition on. Measure voltage between ground and test pins No. 71 and 97 at breakout box. If battery voltage is present at both terminals, go to next step. If battery voltage is not present at one or both terminals, a fault exists in VPWR circuit. Perform «CIRCUIT TEST A»(ref-24260-S17790910942001010400000) .
5. 4) Check PCM Ground Circuit Turn ignition off. Measure resistance between ground and test pins No. 25, 51, 76, 77 and 103 at breakout box. If all readings are less than 5 ohms, replace PCM. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If any reading is 5 ohms or more, a fault exists in ground circuit. Perform «CIRCUIT TEST A»(ref-24260-S17790910942001010400000) , step 10).

CIRCUIT TEST AP - OBD-II READINESS CODE

1. 1) DTC P1000 This DTC indicates operating conditions have not been satisfied for all of the OBD-II monitors to run. Possible causes for this fault are: Drive conditions not satisfied. Keep Alive Memory (KAM) cleared. Faulty Powertrain Control Module (PCM). NOTE: If power to PCM is disconnected, P1000 will be set until OBD-II monitors have run and cleared. Perform all SELF-TESTS and check for DTCs. If any DTCs other than P1000 are present, perform appropriate circuit test and repair as necessary. Clear DTCs and repeat «QUICK TEST»(ref-24260-S02984646372001010400000) . If DTC P1000 is only DTC present, go to next step.
2. 2) Perform Drive Cycle Perform drive cycle. See «DRIVE CYCLE PROCEDURE»(ref-24260-S03879643862001010400000) under ADDITIONAL SYSTEM FUNCTIONS. If DTC P1000 is present, go to next step. If DTC P1000 is not present, no problem is indicated at this time.
3. 3) Verify Certain Operating Conditions Have Been Satisfied Using scan tool, select EOT, VPWR and GPC PIDs from PID/DATA monitor menu. If engine is started and EOT PID value is less than 120°F (49°C), VPWR value must be 11.8-14.0 volts until GPC PID value is zero percent. Using scan tool, monitor MFDES PID value and engine RPM with engine under full load. MDFDES PID value must be more than 37 milligrams/stroke for 12 or more seconds with engine speed at more than 2300 RPM. With engine at normal operating temperature, monitor MFDES PID. MFDES PID value must be less than 12 milligrams/stroke for 12 seconds or more. With all the conditions met in this step, if DTC P1000 is cleared, no problem is indicated at this time. If DTC P1000 is still present, determine DTC clearing fault. Perform all engine performance diagnosis tests. See ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.