MIL Operation
The MIL is located on the instrument panel cluster (IPC).
MIL Function
- The MIL informs the driver that a malfunction has occurred and the vehicle should be taken in for service as soon as possible.
- The MIL illuminates during a bulb test and a system test.
- A DTC will be stored if a MIL is requested by the PCM.
MIL Illumination
- The MIL will illuminate with ignition switch ON and the engine not running.
- The MIL will turn OFF when the engine is started.
- The MIL will remain ON if the self-diagnostic system has detected a malfunction.
- The MIL may turn OFF if the malfunction is not present.
- If the MIL is illuminated and then the engine stalls, the MIL will remain illuminated so long as the ignition switch is ON.
- If the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition switch is cycled OFF, then ON.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 4: This step tests for a short to voltage on the MIL control circuit. With the fuse removed there should be no voltage on the MIL control circuit.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls | |
| 2 | Verify that the instrument panel cluster (IPC) is operational. If the IPC is completely inoperative, refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gages and Console. Command the malfunction indicator lamp (MIL) ON and OFF with a scan tool. Does the MIL turn ON and OFF when commanded with a scan tool? | Go to Intermittent Conditions | Go to Step 3 | |
| 3 | Inspect the fuse that supplies ignition voltage to the cluster. Is the fuse open? | Go to Step 10 | Go to Step 4 | |
| 4 | Turn OFF the ignition. Remove the fuse that supplies voltage to the MIL. Disconnect the powertrain control module (PCM). Turn ON the ignition, with the engine OFF. Measure the voltage from the MIL control circuit in the PCM harness connector to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems. Is the voltage less than the specified value? | 0.3 V | Go to Step 5 | Go to Step 11 |
| 5 | Turn OFF the ignition. Install the fuse that supplies voltage to the MIL. Turn ON the ignition, with the engine OFF. Connect a 3-amp fused jumper wire between the MIL control circuit in the PCM harness connector and a good ground. Does the MIL illuminate? | Go to Step 9 | Go to Step 6 | |
| 6 | Turn OFF the ignition. Remove the instrument panel cluster (IPC). Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Turn ON the ignition, with the engine OFF. Probe the ignition voltage circuit of the IPC harness connector with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 12 | |
| 7 | Test the MIL control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | Go to Step 15 | Go to Step 8 | |
| 8 | Test for an intermittent and for a poor connection at the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 15 | Go to Step 13 | |
| 9 | Test for an intermittent and for a poor connection at the PCM. Refer to Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 15 | Go to Step 14 | |
| 10 | Test all circuits and components that use this voltage supply for excessive current draw. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 15 | Go to Intermittent Conditions | |
| 11 | Repair the short to voltage in the MIL control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | ||
| 12 | Repair the open in the ignition voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | ||
| 13 | Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 15 | ||
| 14 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement? | Go to Step 15 | ||
| 15 | Turn the ignition OFF for 30 seconds. Start the engine. Does the MIL operate correctly? | Go to Step 16 | Go to Step 2 | |
| 16 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List | System OK | |
Malfunction Indicator Lamp (MIL) Inoperative
The MIL is located on the instrument panel (IPC).
MIL Function
- The MIL informs the driver that a malfunction has occurred and the vehicle should be taken in for service as soon as possible.
- The MIL illuminates during a bulb test and a system test.
- A DTC will be stored if a MIL is requested by the diagnostic.
MIL Illumination
- The MIL will illuminate with ignition switch ON and the engine not running.
- The MIL will turn OFF when the engine is started.
- The MIL will remain ON if the self-diagnostic system has detected a malfunction.
- The MIL may turn OFF if the malfunction is not present.
- If the MIL is illuminated and then the engine stalls, the MIL will remain illuminated so long as the ignition switch is ON.
- If the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition switch is cycled OFF, then ON.
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step determines if the condition is with the MIL control circuit or the PCM.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 | Turn OFF the ignition. Disconnect the powertrain control module (PCM). Turn ON the ignition, with the engine OFF. Observe the malfunction indicator lamp (MIL). Is the MIL illuminated? | Go to Step 3 | Go to Step 5 |
| 3 | Remove the instrument panel cluster (IPC). Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Test the MIL control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 4 |
| 4 | Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 6 | |
| 5 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement? | Go to Step 6 | |
| 6 | Turn the ignition OFF for 30 seconds. Start the engine. Does the vehicle operate correctly without any MIL illumination, and without any stored DTCs? | System OK | Go to Diagnostic System Check - Engine Controls |
Malfunction Indicator Lamp (MIL) Always On
Description
The Engine Cranks but Does Not Run diagnostic table is an organized approach to identifying a condition that causes an engine to not start. The diagnostic table directs the service technician to the appropriate system diagnosis. The diagnostic table assumes the following conditions are met
- The battery is completely charged. Refer to «Battery Inspection/Test (Non-HP2)»(ref-187793-S25033739332005090100000) in Engine Electrical.
- The engine cranking speed is acceptable. Refer to «Engine Cranks Slowly»(ref-187793-S20680149172005090100000) in Engine Electrical.
- There is adequate fuel in the fuel tank.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics | ||||
| 1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls | |
| 2 | Turn ON the ignition, with the engine OFF. With a scan tool, observe the DTC information. Does the scan tool display DTC P0230, P0335, P0336, P0601, P0602, P0604, P0606, P1626, or P1631? | Go to Diagnostic Trouble Code (DTC) List | Go to Step 3 | |
| 3 | Does the scan tool display any body control module (BCM) vehicle theft deterrent (VTD) DTCs? | Go to Diagnostic System Check - Theft Deterrent in Theft Deterrent | Go to Step 4 | |
| 4 | Turn ON the ignition, with the engine OFF. Probe both sides of the ETC fuse located in the underhood electrical center with a test lamp connected to a good ground. Does the test lamp illuminate on at least on side of the fuse? | Go to Step 5 | Go to Ignition Relay Diagnosis | |
| 5 | Monitor the ignition 1 signal parameter with a scan tool. Is the ignition 1 signal parameter at the specified value? | B+ | Go to Step 6 | Go to Step 10 |
| 6 | Command the fuel pump ON with a scan tool. Does the fuel pump operate? | Go to Step 7 | Go to Fuel Pump Electrical Circuit Diagnosis | |
| 7 | Turn OFF the ignition. Disconnect a spark plug wire. Install the J 26792 Spark Tester. Attempt to start the engine. Repeat test for remaining cylinders. Does the spark tester spark for all cylinders? | Go to Step 8 | Go to Electronic Ignition (EI) System Diagnosis | |
| 8 | Turn OFF the ignition. Install a fuel pressure gage. Refer to Fuel System Diagnosis (Without Returnless Fuel System) . IMPORTANT: The fuel pump operates for about 2 seconds when the ignition is turned ON. The fuel pressure must be observed when the fuel pump is operating. Turn ON the ignition, with the engine OFF. Observe the fuel pressure while the fuel pump is operating. Is the fuel pressure within the specified range? | 385-425 kPa (55-62 psi) | Go to Step 9 | Go to Fuel System Diagnosis (Without Returnless Fuel System) |
| 9 | Inspect for the following conditions: The engine coolant temperature (ECT) sensor is not close to the actual engine temperature. Refer to DTC P0125 . The duct work between the mass air flow (MAF) sensor and the throttle body for air leaks A restricted exhaust system - Refer to Restricted Exhaust in Engine Exhaust. A malfunctioning MAF sensor may cause a no start or a stall after a start. If you suspect this, disconnect the MAF sensor. The powertrain control module (PCM) will default to the speed density in order to calculate the engine load and the intake air flow. If disconnecting the MAF sensor corrects the condition and the connections are OK. Refer to DTC P0102 . The spark plugs for being gas fouled - Refer to Spark Plug Inspection . An engine mechanical failure that causes an engine not to start such as timing chain, low compression - Refer to Engine Compression Test and Symptoms - Engine Mechanical in Engine Mechanical. Compare the MAP/BARO parameters to another vehicle. The parameter values should be close to each other. Did you complete the action? | Go to Step 13 | ||
| 10 | Test the ignition 1 voltage circuits that are supplied by the PCM 1 fuse for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Replace the fuse if necessary. Did you find and correct the condition? | Go to Step 13 | Go to Step 11 | |
| 11 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 12 | |
| 12 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement? | Go to Step 13 | ||
| 13 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Attempt to start the engine. Does the engine start the continue to run? | Go to Step 14 | Go to Step 2 | |
| 14 | Allow the engine to reach operating temperature. Observe the DTC information with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List | System OK | |
| IMPORTANT |
|---|
| The fuel pump operates for about 2 seconds when the ignition is turned ON. The fuel pressure must be observed when the fuel pump is operating. |
Engine Cranks but Does Not Run
The numbers below refer to the step numbers on the diagnostic table.
- 3: This step determines if the condition is located on the coil side or on the switch side of the fuel pump relay.
- 4: This step verifies that the powertrain control module (PCM) is providing voltage to the fuel pump relay.
- 5: This step tests for an open in the ground circuit to the fuel pump relay.
- 6: This step determines if a voltage is constantly being applied to the fuel pump relay.
- 13: This step determines if the condition with the circuit is intermittent.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 | Turn ON the ignition, with the engine OFF. Command the fuel pump relay ON and OFF with a scan tool. Does the fuel pump turn ON and OFF when commanded with a scan tool? | Go to Diagnostic Aids | Go to Step 3 |
| 3 | Command the fuel pump relay ON and OFF with a scan tool. Does the fuel pump relay turn ON and OFF when commanded with a scan tool? | Go to Step 9 | Go to Step 4 |
| 4 | Turn OFF the ignition. Remove the fuel pump relay. Turn ON the ignition, with the engine OFF. Probe the control circuit of the fuel pump relay with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems. Command the fuel pump relay ON and OFF with a scan tool. Does the test lamp turn ON and OFF when commanded with a scan tool? | Go to Step 5 | Go to Step 6 |
| 5 | Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the fuel pump relay. Command the fuel pump relay ON and OFF with a scan tool. Does the test lamp turn ON and OFF when commanded with a scan tool? | Go to Step 19 | Go to Step 22 |
| 6 | Does the test lamp remain illuminated? | Go to Step 7 | Go to Step 8 |
| 7 | Test the control circuit of the fuel pump relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 27 |
| 8 | Test the control circuit of the fuel pump relay for a short to ground or for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 20 |
| 9 | Turn ON the ignition, with the engine OFF. Does the fuel pump operate continuously? | Go to Step 10 | Go to Step 11 |
| 10 | Turn OFF the ignition. Remove the fuel pump relay. Turn ON the ignition, with the engine OFF. Does the fuel pump operate continuously? | Go to Step 21 | Go to Step 26 |
| 11 | Inspect the fuel pump fuse. Is the fuel pump fuse open? | Go to Step 12 | Go to Step 14 |
| 12 | Test the supply voltage circuit of the fuel pump, between the fuel pump fuse and the fuel pump for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Replace the fuel pump fuse if necessary. Did you find and correct the condition? | Go to Step 28 | Go to Step 13 |
| 13 | Install all removed electrical components. Install a new fuel pump fuse. Command the fuel pump relay ON with a scan tool. Inspect the fuel pump fuse. Is the fuel pump fuse open? | Go to Step 24 | Go to Intermittent Conditions |
| 14 | Turn OFF the ignition. Remove the fuel pump relay. Turn ON the ignition, with the engine OFF. Probe the battery voltage circuit of the fuel pump relay switch with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 15 | Go to Step 23 |
| 15 | Connect a 20-amp fused jumper wire between the battery voltage circuit of the fuel pump relay switch and the supply voltage circuit of the fuel pump. Does the fuel pump operate? | Go to Step 19 | Go to Step 16 |
| 16 | Test the supply voltage circuit of the fuel pump, between the fuel pump relay and the fuel pump for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 17 |
| 17 | IMPORTANT: Inspect the ground circuit for being tight, corrosion on terminals, or damage to the wiring harness. Test the ground circuit of the fuel pump for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition? | Go to Step 28 | Go to Step 18 |
| 18 | Test for an intermittent or for a poor connection at the fuel pump sender assembly connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 24 |
| 19 | Test for an intermittent or for a poor connection at the fuel pump relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 26 |
| 20 | Test for an intermittent and for a poor connection at the harness connector of the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 27 |
| 21 | Repair the short to voltage in the supply voltage circuit of the fuel pump. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | |
| 22 | Repair the open in the fuel pump relay ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | |
| 23 | Repair the open in the battery voltage circuit of the fuel pump relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | |
| 24 | Test for an intermittent and for a poor connection at the fuel pump sender assembly connector within the fuel tank. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the conditions? | Go to Step 28 | Go to Step 25 |
| 25 | Replace the fuel pump sender assembly. Refer to Fuel Sender Assembly Replacement . Replace the fuel pump fuse if necessary. Did you complete the replacement? | Go to Step 28 | |
| 26 | Replace the fuel pump relay. Did you complete the replacement? | Go to Step 28 | |
| 27 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement? | Go to Step 28 | |
| 28 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
| IMPORTANT |
|---|
| Inspect the ground circuit for being tight, corrosion on terminals, or damage to the wiring harness. |
Fuel Pump Electrical Circuit Diagnosis
System Description
The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within two seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within two seconds if ignition reference pulses cease to be detected and the ignition remains ON.
The fuel tank stores the fuel supply. The electric fuel pump supplies fuel through an in-line fuel filter to the fuel injection system. The pump provides fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pressure regulator maintains the correct fuel pressure to the fuel injection system. A separate pipe returns unused fuel to the fuel tank.
The numbers below refer to the step numbers on the diagnostic table.
- 4: This step tests for an internal fuel leak.
- 5: This step tests the fuel pump check valve for a leak down condition.
- 6: This step tests the fuel pressure regulator.
- 10: This step tests for a loss of fuel pressure between the fuel feed pipe shut-off adapter and the fuel pump.
- 11: This step tests for a leaking fuel injector or for a leaking fuel pressure regulator.
- 14: This step tests for a restricted fuel return pipe.
- 16: This step determines if the fuel pressure regulator or the fuel pump is the cause of the low fuel pressure.
- 18: This step verifies that a circuit condition is not the cause of a fuel pressure concern.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Fuel Hose/Pipes Routing Diagram (Without Returnless Fuel System) | ||||
| 1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls | |
| 2 | IMPORTANT: Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks. Turn ON the ignition, with the engine OFF. Command the fuel pump relay ON with a scan tool. Does the fuel pump turn ON when commanded with a scan tool? | Go to Step 3 | Go to Intermittent Conditions | |
| 3 | IMPORTANT: Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks. Turn OFF the ignition. Turn OFF all accessories. CAUTION: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete. Install the J 34730-1A Fuel Pressure Gage. Refer to Fuel Pressure Gage Installation and Removal . Turn ON the ignition, with the engine OFF. IMPORTANT: You may need to command the fuel pump ON several times, in order to obtain the highest possible fuel pressure. Do NOT start the engine. Command the fuel pump ON with a scan tool. Observe the fuel pressure gage with the fuel pump commanded ON. Is the fuel pressure within the specified value? | 380-427 kPa (55-62 psi) | Go to Step 4 | Go to Step 12 |
| 4 | IMPORTANT: The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize, then remain constant. Observe the fuel pressure gage for 1 minute.Does the fuel pressure drop more than the specified value? | 34 kPa (5 psi) | Go to Step 9 | Go to Step 5 |
| 5 | Relieve the fuel pressure to the first specified value. Observe the fuel pressure gage for 1 minute. Does the fuel pressure drop more than the second specified value? | 69 kPa (10 psi) 14 kPa (2 psi) | Go to Step 24 | Go to Step 6 |
| 6 | Turn OFF the ignition for 15 seconds. Turn ON the ignition, with the engine OFF. Monitor the fuel pressure gage. Start the engine. Does the fuel pressure drop the specified value when the engine is started? | 21-69 kPa (3-10 psi) | Go to Step 7 | Go to Step 8 |
| 7 | Operate the vehicle within the conditions of the customer's concerns. Monitor the fuel-related parameters with a scan tool. Do any of the scan tool parameters indicate a lean condition? | Go to Step 17 | Go to Symptoms - Engine Controls | |
| 8 | Disconnect the vacuum hose from the fuel pressure regulator. Monitor the fuel pressure gage. Idle the engine. Apply 12-14 inches of vacuum to the fuel pressure regulator with a hand-held vacuum pump. Does the fuel pressure drop the specified value when the vacuum is applied? | 21-69 kPa (3-10 psi) | Go to Step 21 | Go to Step 23 |
| 9 | Turn OFF the ignition. Disconnect the vacuum hose from the fuel pressure regulator. Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. Inspect for a fuel leak from the vacuum port of the fuel pressure regulator. Is the fuel pressure regulator leaking fuel? | Go to Step 23 | Go to Step 10 | |
| 10 | Turn OFF the ignition. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure . Disconnect the fuel feed hose and the fuel return hose from the fuel rail. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Install the J 37287 Fuel Line Shut-Off Adapters between the fuel hoses and the fuel rail pipes. Open the valves on the fuel pipe shut-off adapters. Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. Bleed the air from the fuel pressure gage. Command the fuel pump ON and OFF with a scan tool. Close the fuel feed pipe shut-off valve. Monitor the fuel pressure gage for 1 minute. Does the fuel pressure remain constant? | Go to Step 19 | Go to Step 11 | |
| 11 | Turn OFF the ignition. Open the shut-off valve for the fuel feed pipe. Turn ON the ignition, with the engine OFF. Command the fuel pump ON and OFF with a scan tool. Close the shut-off valve for the fuel return pipe. Monitor the fuel pressure gage for 1 minute. Does the fuel pressure remain constant? | Go to Step 23 | Go to Step 20 | |
| 12 | Is the fuel pressure more than the specified value? | 427 kPa (62 psi) | Go to Step 14 | Go to Step 13 |
| 13 | Is the fuel pressure more than the specified value? | 0 kPa (0 psi) | Go to Step 16 | Go to Step 17 |
| 14 | Turn OFF the ignition. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure . Disconnect the fuel return hose from the fuel rail return pipe. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Attach a length of flexible fuel hose to the fuel rail outlet passage. Place the open end of the flexible fuel hose into an approved gasoline container. Turn ON the ignition, with the engine OFF. Monitor the fuel pressure gage with the fuel pump operating. Is the fuel pressure within the specified value? | 380-427 kPa (55-62 psi) | Go to Step 22 | Go to Step 15 |
| 15 | Inspect the fuel rail outlet passage for a restriction. Did you find and correct the condition? | Go to Step 25 | Go to Step 23 | |
| 16 | Turn OFF the ignition. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure . Disconnect the fuel return hose from the fuel rail return pipe. Refer to Quick Connect Fitting(s) Service (Metal Collar) . Install the J 37287 between the fuel return pipe and the fuel rail. Open the valve on the fuel pipe shut-off adapter. Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. Bleed the air from the fuel system. Monitor the fuel pressure gage. NOTE: DO NOT allow the fuel pressure to exceed 517 kPa (75 psi). Excessive pressure may damage the fuel system. Slowly close the valve in the fuel pipe shut-off adapter. Command the fuel pump ON with a scan tool. Does the fuel pressure rise above the specified value? | 427 kPa (62 psi) | Go to Step 23 | Go to Step 17 |
| 17 | Inspect the following components for restrictions: The fuel filter The fuel feed pipe Did you find and correct the condition? | Go to Step 25 | Go to Step 18 | |
| 18 | Test for an intermittent and for a poor connection at the harness connectors and the ground circuits of the fuel pump. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 19 | |
| 19 | Remove the fuel sender assembly. Refer to Fuel Sender Assembly Replacement . Inspect the following components: The fuel pump flex hose for damage The in-tank fuel pump harness connectors for bad connections The fuel strainer for restrictions The fuel tank for contaminants Did you find and correct the condition? | Go to Step 25 | Go to Step 24 | |
| 20 | Turn OFF the ignition. Raise the fuel rail, with the fuel lines connected. Refer to Fuel Rail Assembly Replacement . Turn ON the ignition, with the engine OFF. Command the fuel pump relay ON with a scan tool. Locate and replace the leaking fuel injector. Refer to Fuel Injector Replacement . Did you complete the replacement? | Go to Step 25 | ||
| 21 | Repair the vacuum source to the fuel pressure regulator. Did you complete the repair? | Go to Step 25 | ||
| 22 | Locate and repair the restricted fuel return line. Did you complete the repair? | Go to Step 25 | ||
| 23 | IMPORTANT: Before your replace the fuel pressure regulator, inspect for a missing or damaged fuel pressure regulator O-ring seal. Replace the fuel pressure regulator. Refer to Fuel Pressure Regulator Replacement .Did you complete the replacement? | Go to Step 25 | ||
| 24 | Replace the fuel pump. Refer to Fuel Sender Assembly Replacement . Did you complete the replacement? | Go to Step 25 | ||
| 25 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 | |
| IMPORTANT |
|---|
| Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks. |
| IMPORTANT |
|---|
| Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks. |
| CAUTION |
|---|
| Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete. |
| IMPORTANT |
|---|
| You may need to command the fuel pump ON several times, in order to obtain the highest possible fuel pressure. Do NOT start the engine. |
| IMPORTANT |
|---|
| The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize, then remain constant. |
| NOTE |
|---|
| DO NOT allow the fuel pressure to exceed 517 kPa (75 psi). Excessive pressure may damage the fuel system. |
| IMPORTANT |
|---|
| Before your replace the fuel pressure regulator, inspect for a missing or damaged fuel pressure regulator O-ring seal. |
Fuel System Diagnosis
The scan tool is first used to energize the fuel pump. The fuel injector tester is then used to pulse each injector for a precise amount of time, allowing a measured amount of fuel into the manifold. This causes a drop in system fuel pressure that can be recorded and used to compare each injector.
Scheme 67
| Callout | Component Name |
|---|---|
| 1 | First Fuel Pressure Gage Reading |
| 2 | Second Fuel Pressure Gage Reading |
| Cylinder | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| 1st Reading | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) |
| 2nd Reading | 131 kPa (19 psi) | 117 kPa (17 psi) | 124 kPa (18 psi) | 145 kPa (21 psi) |
| Amount of Drop | 165 kPa (24 psi) | 179 kPa (26 psi) | 172 kPa (25 psi) | 151 kPa (22 psi) |
| Average Range: 156-176 kPa (22.5-25.5 psi) | Injector OK | Replace fuel injector - too much fuel pressure drop | Injector OK | Replace fuel injector - too little fuel pressure drop |
Fuel Injector Balance Test Example (Typical)
The numbers below refer to the step numbers on the diagnostic table.
- 6: If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading. Refer to the illustration above.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls | |
| 2 | Did you perform the Fuel Injector Coil Test? | Go to Step 3 | Go to Fuel Injector Coil Test | |
| 3 | IMPORTANT: Do not perform this test if the engine coolant temperature (ECT) is above 94° C (201° F). Observe the ECT Sensor parameter with a scan tool.Is the ECT Sensor parameter less than the specified value? | 94° C (201° F) | Go to Step 4 | |
| 4 | IMPORTANT: Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. Turn OFF the ignition. Install the fuel pressure gage. Refer to Fuel Pressure Gage Installation and Removal . Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. IMPORTANT: You may need to command the fuel pump ON a few times, in order to obtain the highest possible fuel pressure. Do not start the engine. Observe the fuel pressure gage, with the fuel pump commanded ON. Is the fuel pressure within the specified range? | 380-427 kPa (55-62 psi) | Go to Step 5 | Go to Fuel System Diagnosis (Without Returnless Fuel System) |
| 5 | IMPORTANT: The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. Monitor the fuel pressure gage for 1 minute.Does the fuel pressure drop more than the specified value? | 34 kPa (5 psi) | Go to Fuel System Diagnosis (Without Returnless Fuel System) | Go to Step 6 |
| 6 | NOTE: Do Not repeat any portion of this test before running the engine in order to prevent the engine from flooding. IMPORTANT: Refer to the illustration in the supporting text when performing the following steps. Connect the J 39021 Fuel Injector Coil and Balance Tester and the J 39021-380 Fuel Injector Test Harness to a fuel injector. Set the amperage supply selector switch on the fuel injector tester to the Balance Test 0.5-2.5 amp position. Command the fuel pump ON and OFF with a scan tool. IMPORTANT: Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. Record the fuel pressure indicated by the fuel pressure gage after the fuel pressure stabilizes. This is the first pressure reading. Energize the fuel injector by depressing the Push to Start Test button on the fuel injector tester. Record the fuel pressure indicated by the fuel pressure gage. This is the second fuel pressure reading. Repeat steps 1-6 for each fuel injector. Subtract the second pressure reading from the first pressure reading for one fuel injector. The result is the pressure drop value. Obtain a pressure drop value for each fuel injector. Add all of the individual pressure drop values. This is the total pressure drop. Divide the total pressure drop by the number of fuel injectors. This is the average pressure drop. Does any fuel injector have a pressure drop value that is more than the average pressure drop or less than the average pressure drop by the specified value? | 10 kPa (1.5 psi) | Go to Step 7 | Go to Symptoms - Engine Controls |
| 7 | Perform the Fuel Injector Cleaning Procedure . Did you complete the procedure? | Go to Step 8 | ||
| 8 | Operate the vehicle in order to verify the repair. Does a driveability condition still exist? | Go to Symptoms - Engine Controls | System OK | |
| IMPORTANT |
|---|
| Do not perform this test if the engine coolant temperature (ECT) is above 94° C (201° F). |
| IMPORTANT |
|---|
| Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. |
| IMPORTANT |
|---|
| You may need to command the fuel pump ON a few times, in order to obtain the highest possible fuel pressure. Do not start the engine. |
| IMPORTANT |
|---|
| The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. |
| NOTE |
|---|
| Do Not repeat any portion of this test before running the engine in order to prevent the engine from flooding. |
| IMPORTANT |
|---|
| Refer to the illustration in the supporting text when performing the following steps. |
| IMPORTANT |
|---|
| Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. |
Fuel Injector Balance Test with Special Tool
The scan tool is first used to energize the fuel pump. The scan tool is then used to pulse each injector for a precise amount of time, allowing a measured amount of fuel into the manifold. This causes a drop in system fuel pressure that can be recorded and used to compare the flow through each injector.
| Cylinder | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| 1st Reading | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) | 296 kPa (43 psi) |
| 2nd Reading | 131 kPa (19 psi) | 117 kPa (17 psi) | 124 kPa (18 psi) | 145 kPa (21 psi) |
| Amount of Drop | 165 kPa (24 psi) | 179 kPa (26 psi) | 172 kPa (25 psi) | 151 kPa (22 psi) |
| Average Range: 156-176 kPa (22.5-25.5 psi) | Injector OK | Replace fuel injector - too much fuel pressure drop | Injector OK | Replace fuel injector - too little fuel pressure drop |
Fuel Injector Balance Test Example (Typical)
The numbers below refer to the step numbers on the diagnostic table.
- 5: If the pressure drop value for each fuel injector is within 10 kPa (1.5 psi) of the average pressure drop value, the fuel injectors are flowing properly. Calculate the pressure drop value for each fuel injector by subtracting the second pressure reading from the first pressure reading.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls | |
| 2 | Did you perform the Fuel Injector Coil Test? | Go to Step 3 | Go to Fuel Injector Coil Test | |
| 3 | IMPORTANT: Do not perform this test if the engine coolant temperature (ECT) is above 94° C (201° F). IMPORTANT: Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. Turn OFF the ignition. Turn OFF all accessories. Install the fuel pressure gage. Refer to Fuel Pressure Gage Installation and Removal . Turn ON the ignition, with the engine OFF. Command the fuel pump ON with a scan tool. IMPORTANT: You may need to command the fuel pump ON a few times in order to obtain the highest possible fuel pressure. Do not start the engine. Observe the fuel pressure gage, with the fuel pump commanded ON. Is the fuel pressure within the specified value? | 380-427 kPa (55-62 psi) | Go to Step 4 | Go to Fuel System Diagnosis (Without Returnless Fuel System) |
| 4 | IMPORTANT: The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. Observe the fuel pressure gage for 1 minute.Does the fuel pressure drop more than the specified value? | 34 kPa (5 psi) | Go to Fuel System Diagnosis (Without Returnless Fuel System) | Go to Step 5 |
| 5 | NOTE: Refer to Fuel Injector Balance Test Notice in Cautions and Notices. Select the Fuel Injector Balance Test function with a scan tool. Select an injector to be tested. Press Enter. This will prime the fuel system. IMPORTANT: Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. Record the fuel pressure indicated by the fuel pressure gage after the fuel pressure stabilizes. This is the 1st pressure reading. Energize the fuel injector by depressing the Pulse Injector button on the scan tool. This will energize the injector and decrease the fuel pressure. Record the fuel pressure indicated by the fuel pressure gage after the fuel injector has stopped pulsing. This is the 2nd pressure reading. Press Enter again to bring you back to the Select Injector screen. Repeat for each fuel injector. Subtract the 2nd pressure reading from the 1st pressure reading for one fuel injector. The result is the pressure drop value. Obtain a pressure drop value for each fuel injector. Add all of the individual pressure drop values. This is the total pressure drop. Divide the total pressure drop by the number of fuel injectors. This is the average pressure drop. Does any fuel injector have a pressure drop value that is either higher than the average pressure drop or lower than the average pressure drop by the specified value? | 10 kPa (1.5 psi) | Go to Step 6 | Go to Symptoms - Engine Controls |
| 6 | Perform the Fuel Injector Cleaning Procedure . Did you complete the procedure? | Go to Step 7 | ||
| 7 | Operate the vehicle in order to verify the repair. Does a driveability condition still exist? | Go to Symptoms - Engine Controls | System OK | |
| IMPORTANT |
|---|
| Do not perform this test if the engine coolant temperature (ECT) is above 94° C (201° F). |
| IMPORTANT |
|---|
| Verify there is adequate fuel in the fuel tank before proceeding with this diagnostic. |
| IMPORTANT |
|---|
| You may need to command the fuel pump ON a few times in order to obtain the highest possible fuel pressure. Do not start the engine. |
| IMPORTANT |
|---|
| The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize and remain constant. |
| NOTE |
|---|
| Refer to Fuel Injector Balance Test Notice in Cautions and Notices. |
| IMPORTANT |
|---|
| Record the fuel pressure value immediately after the fuel injector stops pulsing. The fuel pressure may rise after the fuel injector stops pulsing. Do not record the higher fuel pressure value. |
Fuel Injector Balance Test with Tech 2
The fuel tank leak test is used to locate any fuel or fuel vapor escaping the fuel tank area. Fuel vapors escaping above the fuel level will be detected when the evaporative emission (EVAP) diagnostics complete one test cycle. The malfunction indicator lamp (MIL) will illuminate after the EVAP diagnostics have failed two test cycles.
The numbers below refer to the step numbers on the diagnostic table.
- 4: This step tests for fuel leaks below the fuel tank fuel level.
- 5: This step tests for fuel vapors escaping above the fuel level in the fuel tank.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 | CAUTION: Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Inspect the fuel tank and fuel pipes for damage or external leaks. Did you find fuel leaking from the fuel tank? | Go to Step 6 | Go to Step 3 |
| 3 | Turn ON the ignition, with the engine OFF. Command the fuel pump relay ON with a scan tool. Inspect for fuel leaking from the fuel pipes. Did fuel leak from the fuel pipes? | Go to Step 7 | Go to Step 4 |
| 4 | Turn OFF the ignition. Install the J 41413-200 Evaporative Emissions System Tester (EEST) and the J 41415-40 Fuel Tank Cap Adaptor or the GE-41415-50 Interrupted Thread Fuel Tank Cap Adapter. IMPORTANT: If the floating indicator registers any flow after stabilizing, a leak is evident. Test for a fuel tank leak referring to the J 41413-210 Operation Manual. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Inspect for a fuel leak while the system is under pressure. Did fuel leak from the fuel tank? | Go to Step 6 | Go to Step 5 |
| 5 | Using the J 41413-200 and the J 41413-210 Operation Manual, introduce smoke into the evaporative emission (EVAP) system. IMPORTANT: It may be necessary to partially lower the fuel tank. Refer to Fuel Tank Replacement . Inspect for leaks in any of the following locations: The fuel tank, fill limiter vent valve, the pressure relief valve, and the grade vent valves - Refer to Fuel Tank Replacement . The fuel sender housing and the fuel sender seal - Refer to Fuel Sender Assembly Replacement . The fuel tank pressure (FTP) sensor seal - Refer to Fuel Tank Pressure Sensor Replacement . The EVAP vapor pipes - Refer to Evaporative Emission (EVAP) Hoses/Pipes Replacement - Canister/Fuel Tank and Evaporative Emission (EVAP) Hoses/Pipes Replacement - Chassis . The fuel fill pipe and hose - Refer to Filler Tube Replacement . If equipped with a rear tank, the fuel tank, the fill limiter vent valve, the pressure relief valve, and the rollover valves - Refer to Fuel Tank Replacement . If equipped with a rear tank, the fuel sender housing and the fuel sender seal - Refer to Fuel Sender Assembly Replacement . Did you find and correct the condition? | Go to Step 8 | Go to Diagnostic Aids |
| 6 | Replace the fuel tank. Refer to Fuel Tank Replacement . Did you complete the repair? | Go to Step 8 | |
| 7 | Replace the leaking fuel pipe. Refer to Fuel Hose/Pipes Assembly Replacement . Did you complete the replacement? | Go to Step 8 | |
| 8 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
| CAUTION |
|---|
| Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby. |
| IMPORTANT |
|---|
| If the floating indicator registers any flow after stabilizing, a leak is evident. |
| IMPORTANT |
|---|
| It may be necessary to partially lower the fuel tank. Refer to Fuel Tank Replacement . |
Fuel Tank Leak Test
Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system, and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust, or deterioration.
Alcohol concentrations of 10 percent or greater in fuel can be detrimental to fuel system components. Alcohol contamination may cause fuel system corrosion, deterioration of rubber components, and subsequent fuel filter restriction. Some types of alcohol are more detrimental to fuel system components than others. Ethanol is commonly used in gasoline, but in concentrations of no more than 10 percent. Some fuels, such as E85, contain a very high percentage of ethanol. Fuel with more than 10 percent ethanol may cause driveability conditions such as hesitation, lack or power, stalling, or no start.
Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system, and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust or deterioration.
Ethanol concentrations of greater than 10 percent in non-blended gasoline, or greater than 85 percent with E85 blended gasoline for flexible fuel applications, can cause driveability conditions and may contribute to fuel system deterioration. Excessive ethanol concentrations can result in driveability conditions such as hesitation, lack of power, stalling, or a no start, and may contribute to fuel system corrosion, deterioration of fuel system components, and a restricted fuel filter.
The numbers below refer to the step numbers on the diagnostic table.
- 5: Monitoring the misfire current counters determines if a fault is present.
- 12: A good indication that the fuse is open is all off the misfire current counters are incrementing on one side of the engine. Inspect the ignition positive voltage circuit for a grounded circuit. If the fuse is open and the ignition coil circuits are OK, inspect the injector circuits for being grounded.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | Go to Diagnostic System Check - Engine Controls | |
| 2 | Attempt to start the engine. Does the engine start and run? | Go to Step 5 | Go to Step 3 | |
| 3 | Observe the Engine Speed parameter with a scan tool. Crank the engine. Does the scan tool indicate RPM is present? | Go to Step 7 | Go to Step 4 | |
| 4 | Is DTC P0335, P0336, or P0351-P0358 also set? | Go to Diagnostic Trouble Code (DTC) List | Go to Step 16 | |
| 5 | Idle the engine. Observe the misfire current counters on the scan tool. Does the scan tool display any misfire current counters incrementing? | Go to Step 6 | Go to Diagnostic Aids | |
| 6 | Do the misfire current counters increment for most cylinders on one bank of the engine? | Go to Step 12 | Go to Step 7 | |
| 7 | Inspect the spark plug wire for open circuits, cracks, or improper seating of terminals at the spark plug or coil before proceeding with test. Refer to Spark Plug Wire Inspection . Inspect for spark at the plug with the J 26792 Spark Tester or equivalent while cranking. A few sparks, then nothing is considered no spark. Is adequate spark present? | Go to Step 33 | Go to Step 8 | |
| 8 | Measure the spark plug wire resistance. Refer to Spark Plug Wire Inspection . Is the resistance more than the specified value? | 1,000 ohms/ft | Go to Step 32 | Go to Step 9 |
| 9 | Turn OFF the ignition. Disconnect the inoperative ignition coil. Turn ON the ignition, with the engine OFF. Probe the ignition 1 voltage circuit of the ignition coil with a test lamp connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | Go to Step 10 | Go to Step 13 | |
| 10 | Probe the ignition 1 voltage circuit at the ignition coil with a test lamp connected to the ground circuit of the ignition coil. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | Go to Step 11 | Go to Step 14 | |
| 11 | Probe the ignition 1 voltage circuit at the ignition coil with a test lamp connected to the low reference circuit of the ignition coil. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | Go to Step 20 | Go to Step 15 | |
| 12 | Inspect for an open INJ 1 or INJ 2 fuse. Is the fuse open? | Go to Step 29 | Go to Step 23 | |
| 13 | Disconnect the main ignition coil 8-way connector. Probe the ignition 1 voltage circuit at the ignition coil main 8-way connector using the test lamp connected to battery ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | Go to Step 24 | Go to Step 23 | |
| 14 | Disconnect the main ignition coil 8-way connector. Probe the ignition 1 voltage circuit on the harness side with a test lamp connected to the ground circuit of the ignition coil. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | Go to Step 18 | Go to Step 26 | |
| 15 | Disconnect the main ignition coil 8-way connector. Probe the ignition 1 voltage circuit on the harness side with a test lamp connected to the low reference circuit of the ignition coil. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | Go to Step 19 | Go to Step 28 | |
| 16 | Turn ON the ignition, with the engine OFF. Disconnect the crankshaft position (CKP) sensor. Measure the voltage from the CKP sensor 12-volt reference circuit and a good ground with the DMM. Compare the measured voltage with the system voltage. Is the difference in the voltage more than the specified value? | 0.5 V | Go to Step 17 | Go to Step 30 |
| 17 | Test for a short to ground in the CKP 12-volt reference circuit or the camshaft position (CMP) sensor 12-volt reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 22 | |
| 18 | Test for an intermittent and for a poor connection at the ignition coil 8-way connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 25 | |
| 19 | Test for an intermittent and for a poor connection at the ignition coil 8-way connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 27 | |
| 20 | Test for an intermittent and for a poor connection at the ignition coil. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 31 | |
| 21 | Test for an intermittent and for a poor connection at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 30 | |
| 22 | Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 34 | |
| 23 | Repair the open or high resistance in the ignition 1 voltage circuit between the fuse block and the splice. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | ||
| 24 | Repair the open or high resistance in the ignition 1 voltage circuit between the splice and the ignition coil connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | ||
| 25 | Repair the open in the ground circuit between the main 8-way connector and the ignition coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | ||
| 26 | Repair the open in the ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | ||
| 27 | Repair the open in the low reference circuit between the main 8-way connector and the ignition coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | ||
| 28 | Repair the open in the low reference circuit between the PCM and the splice. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | ||
| 29 | Repair the ignition 1 voltage for a short to ground. Refer to Wiring Repairs in Wiring Systems. Replace the fuse. Did you complete the repair? | Go to Step 35 | ||
| 30 | Replace the CKP sensor. Refer to Crankshaft Position (CKP) Sensor Replacement . Did you complete the replacement? | Go to Step 35 | ||
| 31 | Replace the ignition coil. Refer to Ignition Coil(s) Replacement . Did you complete the replacement? | Go to Step 35 | ||
| 32 | Replace the spark plug wire. Refer to Spark Plug Wire Replacement . Did you complete the replacement? | Go to Step 35 | ||
| 33 | Replace the spark plug. Refer to Spark Plug Replacement . Did you complete the replacement? | Go to Step 35 | ||
| 34 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement? | Go to Step 35 | ||
| 35 | Attempt to start the engine. Does the engine start and continue to run? | Go to Step 36 | Go to Step 3 | |
| 36 | Clear the DTCs with a scan tool. Turn OFF the engine for 30 seconds. Start the engine. Allow the engine to reach operating temperature. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List | System OK | |
Electronic Ignition (EI) System Diagnosis
Several states require that a vehicle pass on-board diagnostic (OBD) system tests and the inspection/maintenance (I/M) emission inspection in order to renew license plates. This is accomplished by viewing the I/M System Status display on a scan tool. Using a scan tool, the technician can observe the I/M System Status in order to verify that the vehicle meets the criteria that comply with the local area requirements.
The purpose of the inspection maintenance (I/M) Complete System Set Procedure is to satisfy the enable criteria necessary to execute all of the I/M readiness diagnostics, and to complete the trips for those particular diagnostics. When all diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform this test when more than one or all of the I/M System Status indicators are set to NO.
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step is to run the HO2S heater tests and initiate the EVAP System Test. Preprogramming the scan tool will reduce the amount of time the oxygen sensor heaters operate while verifying the enable criteria.
- 3: This step is to run the EVAP, the AIR and the oxygen sensor tests. The EVAP test begins once the engine coolant reaches a calibrated temperature. The AIR test, if equipped, begins shortly after Closed Loop and the indicated speed is achieved. The oxygen sensor tests begin once the engine is at operating temperature, in Closed Loop Fuel Control, and a calibrated amount of time has elapsed.
- 4: This step is to run the Catalyst Tests. This test runs during the idle period immediately following a cruise period that meets a minimum calibrated RPM and time period.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| CAUTION: Refer to Road Test Caution in Cautions and Notices. | ||||
| 1 | Did you perform the Inspection/Maintenance (I/M) System Check? | Go to Step 2 | Go to Inspection/Maintenance (I/M) System Check | |
| 2 | IMPORTANT: Whenever the ignition is turned ON, ignition positive voltage is supplied to the heated oxygen sensor (HO2S) heaters. After verifying the enable criteria, turn OFF the ignition for approximately 5 minutes in order to allow the sensors to cool before continuing with the test. Once the engine is started, DO NOT turn the engine OFF for the remaining portion of the set procedure. Preprogram the scan tool with the vehicle information before the ignition is turned ON. Ensure that the vehicle is within the Conditions for Running specified in the supporting text. Turn OFF all of the accessories, including the A/C, and blower fan. Set the vehicle parking brake. Verify the transmission is in Park for automatic transmissions and Neutral for manual transmissions. Start the engine and allow it to idle for the specified time. Is the action complete? | 2 minutes | Go to Step 3 | |
| 3 | In order for the next group of tests to run, the vehicle must operate in the following conditions: Acceleration at part throttle to 90 km/h (55 mph), with this speed maintained until the engine reaches operating temperature. This may be up to 10 minutes depending on the start up coolant temperature. Continue operation under these conditions for an additional 6 minutes. Is the action complete? | Go to Step 4 | ||
| 4 | In order for the next group of tests to run, the vehicle must operate in the following conditions: Acceleration at part throttle to 75-89 km/h (45-55 mph) with this speed maintained for 2 minutes. Deceleration to 0 km/h (0 mph). Engine idling for 2 minutes while the following criteria are maintained: Service brake depressed Automatic transmission in drive Manual transmission in neutral with the clutch pedal depressed Is the action complete? | Go to Step 5 | ||
| 5 | Observe the I/M System Status display with a scan tool. Did all of the I/M System Status indicators update to YES? | Go to Step 6 | Go to the I/M System Set Procedure for the systems that have not updated | |
| 6 | Observe the emission related DTC portion of the I/M System Status display with a scan tool. Does the scan tool indicate any emission related DTCs set? | Go to Diagnostic Trouble Code (DTC) List | System OK | |
| CAUTION |
|---|
| Refer to Road Test Caution in Cautions and Notices. |
| IMPORTANT |
|---|
| Whenever the ignition is turned ON, ignition positive voltage is supplied to the heated oxygen sensor (HO2S) heaters. After verifying the enable criteria, turn OFF the ignition for approximately 5 minutes in order to allow the sensors to cool before continuing with the test. Once the engine is started, DO NOT turn the engine OFF for the remaining portion of the set procedure. |
Inspection/Maintenance (I/M) Complete System Set Procedure
The purpose of this test is to satisfy the enable criteria necessary to execute inspection/maintenance (I/M) readiness diagnostics for the catalyst system. The test may be used to set the I/M System Status indicators to YES. The I/M System Status display on the scan tool provides an indication of whether the control module has completed the required tests. The I/M System Status does not indicate that the tests have passed or failed. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made even if all of the other tests for that system have not run.
The purpose of this test is to satisfy the enable criteria necessary in order to execute the inspection/maintenance (I/M) readiness diagnostics for the evaporative emission (EVAP) system. The test may be used in order to set the I/M System Status indicators to YES. The I/M System Status Display on the scan tool provides an indication of when the control module has completed the required tests. The I/M System Status does not indicate that the tests have passed or failed. When all of the diagnostics for a specific system have run and passed and I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the other tests for that system have not run. Performing a visual inspection prior to running the EVAP test may prevent having to repeat the test. A failed or aborted test will require the vehicle to cool down in order to meet the enable criteria to run another test.
The purpose of this test is to satisfy the enable criteria necessary to execute inspection/maintenance (I/M) readiness diagnostics for the oxygen sensor (O2S, HO2S) system. The test may be used to set the I/M System Status to YES. The I/M System Status display on the scan tool provides an indication of whether the control module has completed the required tests. The I/M System Status does not indicate that the tests have passed or failed. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the other tests for that system have not run.
The purpose of this test is to satisfy the enable criteria necessary to execute inspection/maintenance (I/M) readiness diagnostics for the heated oxygen sensor (HO2S) heater system. The test may be used to set the I/M System Status to YES. The I/M System Status display on the scan tool provides an indication of whether the control module has completed the required tests. The I/M System Status does not indicate that the tests have passed or failed. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the other tests for that system have not run.