Dtcs P3400 to U1403: Other Jeep Commander I

Monitor Conditions

1. When Monitored: Transition from 8 to 4 cylinder mode.

Set Conditions

1. Set Condition: O2 sensor readings on Bank 1 side indicate a lean condition while in 4 cylinder mode. One trip fault.

Possible Causes

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: When the PCM recognizes a problem with the Solenoid Control circuit. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 634

Scheme 635

Scheme 636

Scheme 637

Scheme 638

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. NOTE: Diagnose any Deactivation or Oil Pressure DTCs before continuing with this test. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) MDS SOLENOID NO. 1 Turn the ignition off. Gain access to the MDS Solenoid No. 1. Disconnect the MDS Solenoid No. 1 harness connector. Ignition on, engine not running. Turn off all accessories. Using a 12-volt test light connected to the (Z42) Ground circuit, probe the (K451) MDS Solenoid No. 1 Control circuit. With a scan tool, actuate the MDS Solenoid 1. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. Does the 12-volt test light illuminate accordingly? Yes Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. If OK, replace the MDS Solenoid No. 1. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
3. 3) (Z42) GROUND CIRCUIT OPEN Turn the ignition off. Using a 12-volt test light connected to the 12-volts, probe the (Z42) Ground circuit in the MDS Solenoid No. 1 harness connector. Does the test light illuminate brightly? Yes Go to 4) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (K451) MDS SOLENOID NO. 1 CONTROL CIRCUIT SHORTED TO VOLTAGE Disconnect the C3 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K451) MDS Solenoid No. 1 Control circuit in the MDS Solenoid No. 1 connector. Is there any voltage present? Yes Repair the short to voltage in the (K451) MDS Solenoid No. 1 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) .
5. 5) (K451) MDS SOLENOID NO. 1 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Measure the resistance between ground and the (K451) MDS Solenoid No. 1 Control circuit in the MDS Solenoid No. 1 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K451) MDS Solenoid No. 1 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K451) MDS SOLENOID NO. 1 CONTROL CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K451) MDS Solenoid No. 1 Control circuit from the MDS Solenoid No. 1 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K451) MDS Solenoid No. 1 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Solenoid and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched, or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: The MDS fails to engage for cylinder 1. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 639

Scheme 640

Scheme 641

Scheme 642

Scheme 643

Scheme 644

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) CHECKING PCM CONTROL SIDE FOR THE MDS SOLENOID (C112) Turn the ignition off. Disconnect the C112 harness connector. Using a 12-volt test light, jumper from the (Z42) Ground Circuit and the (K451) MDS Solenoid No. 1 Control Circuit in the C112 harness connector (PCM side). Turn the ignition on. With the scan tool, actuate the MDS Solenoid No. 1. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. Does the 12-volt test light illuminate accordingly? Yes Go to 3) . No Go to 4) .
3. 3) MDS SOLENOID RESISTANCE Turn the ignition off. Measure the resistance between the (Z42) Ground Circuit and the (K451) MDS Solenoid No. 1 Control Circuit in the C112 harness connector (MDS side). NOTE: It is important to follow the below temp/resistance values to ensure an accurate reading. MDS SOLENOID RESISTANCE TEMPERATURE VALUE ± -7° C (20° F) RESISTANCE (OHMS) ±.25 ohms -18° C (0° F) 8.8 ohms 0° C (32° F) 9.5 ohms 20° C (68° F) 10.3 ohms 38° C (100° F) 11 ohms 66° C (150° F) 12.2 ohms 93° C (200° F) 13.4 ohms 121° C (250° F) 14.4 ohms 149° C (300° F) 15.6 ohms Is the resistance within an acceptable range? Yes Go to 7) . No Visually and Physically inspect the wiring harness between the C112 connector and the MDS Solenoid connector. Repair as necessary. If OK, replace the MDS Solenoid in accordance with the Service Information.
4. 4) (Z42) GROUND CIRCUIT OPEN (PCM SIDE) Turn the ignition off. Using a 12-volt test light connected to 12-volts, probe the (Z42) Ground circuit in the C112 harness connector (PCM side). Does the test light illuminate brightly? Yes Go to 5) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) (K451) MDS SOLENOID NO. 1 CONTROL CIRCUIT SHORTED TO GROUND (PCM SIDE) Turn the ignition off. Disconnect the C3 PCM harness connector. Measure the resistance between ground and the (K451) MDS Solenoid No. 1 Control circuit in the C112 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K451) MDS Solenoid No. 1 Control circuit between the PCM harness connector and the C112 harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K451) MDS SOLENOID NO. 1 CONTROL CIRCUIT OPEN (PCM SIDE) CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K451) MDS Solenoid No. 1 Control circuit from the C112 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Replace and program the Powertrain Control Module in accordance with the service information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Repair the open in the (K451) MDS Solenoid No. 1 Control circuit between the C112 harness connector and the PCM harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) MDS SOLENOID 1 Turn the ignition off. Remove the Intake Manifold per Service Information. Reconnect the PCM harness connector. Turn the ignition on. With the scan tool actuate the MDS Solenoid 1. Can you feel and hear the Solenoid Actuating? Yes Go to 8) . No Remove the Solenoid (1) and check for any debris that may be blocking the oil passages (3) to the Solenoid. If the passages are clogged, clean the passages and replace the MDS Solenoid 1. If the passages are not clogged with debris, replace the MDS Solenoid 6.
8. 8) OIL PASSAGES RESTRICTED Turn the ignition off. Remove both Solenoids on Bank 1 of the engine block. Remove the Bank 1 Cylinder Head per Service Information. Remove the Lifters from the right engine bank. Inspect the oil passages to the Solenoids and from the Solenoids to the lifters. Are the passages blocked? Yes Clean the oil passages as necessary. If the entire engine is restricted disassembly of the entire engine block may be necessary. No Replace both sets of lifters if no other possible causes remain.

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: When the PCM recognizes a problem with the Solenoid Control circuit. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 645

Scheme 646

Scheme 647

Scheme 648

Scheme 649

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. NOTE: Diagnose any Deactivation or Oil Pressure DTCs before continuing with this test. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) MDS SOLENOID NO. 4 Turn the ignition off. Gain access to the MDS Solenoid No. 4. Disconnect the MDS Solenoid No. 4 harness connector. Ignition on, engine not running. Turn off all accessories. Using a 12-volt test light connected to the (Z42) Ground circuit, probe the (K452) MDS Solenoid No. 4 Control circuit. With a scan tool, actuate the MDS Solenoid 4. NOTE: The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. Does the 12-volt test light illuminate accordingly? Yes Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. If OK, replace the MDS Solenoid No. 4. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
3. 3) (Z42) GROUND CIRCUIT OPEN Turn the ignition off. Using a 12-volt test light connected to the 12-volts, probe the (Z42) Ground circuit in the MDS Solenoid No. 4 harness connector. Does the test light illuminate brightly? Yes Go to 4) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (K452) MDS SOLENOID NO. 4 CONTROL CIRCUIT SHORTED TO VOLTAGE Disconnect the C1 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K452) MDS Solenoid No. 4 Control circuit in the MDS Solenoid No. 4 harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K452) MDS Solenoid No. 4 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) .
5. 5) (K452) MDS SOLENOID NO. 4 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Measure the resistance between ground and the (K452) MDS Solenoid No. 4 Control circuit in the MDS Solenoid No. 4 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K452) MDS Solenoid No. 4 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K452) MDS SOLENOID NO. 4 CONTROL CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K452) MDS Solenoid No. 4 Control circuit from the MDS Solenoid No. 4 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K452) MDS Solenoid No. 4 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Solenoid and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched, or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: The MDS fails to engage for cylinder 4. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 650

Scheme 651

Scheme 652

Scheme 653

Scheme 654

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) CHECKING PCM CONTROL SIDE FOR THE MDS SOLENOID (C112) Turn the ignition off. Disconnect the C112 harness connector. Using a 12-volt test light, jumper from the (Z42) Ground Circuit and the (K452) MDS Solenoid No. 4 Control Circuit in the C112 harness connector (PCM side). Turn the ignition on. With the scan tool, actuate the MDS Solenoid No. 4. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. Does the 12-volt test light illuminate accordingly? Yes Go to 3) . No Go to 4) .
3. 3) MDS SOLENOID RESISTANCE Turn the ignition off. Measure the resistance between the (Z42) Ground Circuit and the (K452) MDS Solenoid No. 4 Control Circuit in the C112 harness connector (MDS side). NOTE: It is important to follow the below temp/resistance values to ensure an accurate reading. MDS SOLENOID RESISTANCE TEMPERATURE VALUE ± -7° C (20° F) RESISTANCE (OHMS) ±.25 ohms -18° C (0° F) 8.8 ohms 0° C (32° F) 9.5 ohms 20° C (68° F) 10.3 ohms 38° C (100° F) 11 ohms 66° C (150° F) 12.2 ohms 93° C (200° F) 13.4 ohms 121° C (250° F) 14.4 ohms 149° C (300° F) 15.6 ohms Is the resistance within an acceptable range? Yes Go to 7) . No Visually and Physically inspect the wiring harness between the C112 connector and the MDS Solenoid connector. Repair as necessary. If OK, replace the MDS Solenoid in accordance with the Service Information.
4. 4) (Z42) GROUND CIRCUIT OPEN (PCM SIDE) Turn the ignition off. Using a 12-volt test light connected to 12-volts, probe the (Z42) Ground circuit in the C112 harness connector (PCM side). Does the test light illuminate brightly? Yes Go to 5) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) (K452) MDS SOLENOID NO. 4 CONTROL CIRCUIT SHORTED TO GROUND (PCM SIDE) Turn the ignition off. Disconnect the C1 PCM harness connector. Measure the resistance between ground and the (K452) MDS Solenoid No. 4 Control circuit in the C112 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K452) MDS Solenoid No. 4 Control circuit between the PCM harness connector and the C112 harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K452) MDS SOLENOID NO. 4 CONTROL CIRCUIT OPEN (PCM SIDE) CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K452) MDS Solenoid No. 4 Control circuit from the C112 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Replace and program the Powertrain Control Module in accordance with the service information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Repair the open in the (K452) MDS Solenoid No. 4 Control circuit between the C112 harness connector and the PCM harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) MDS SOLENOID 4 Turn the ignition off. Remove the Intake Manifold per Service Information. Reconnect the C1 PCM harness connector. Turn the ignition on. With the scan tool actuate the MDS Solenoid 4. Can you feel and hear the Solenoid Actuating? Yes Go to 8) . No Remove the Solenoid (1) and check for any debris that may be blocking the oil passages (3) to the Solenoid. If the passages are clogged, clean the passages and replace the MDS Solenoid 4. If the passages are not clogged with debris, replace the MDS Solenoid 4.
8. 8) OIL PASSAGES RESTRICTED Turn the ignition off. Remove both Solenoids on Bank 2 of the engine block. Remove the Bank 2 Cylinder Head per Service Information. Remove the Lifters from the right engine bank. Inspect the oil passages to the Solenoids and from the Solenoids to the lifters. Are the passages blocked? Yes Clean the oil passages as necessary. If the entire engine is restricted disassembly of the entire engine block may be necessary. No Replace both sets of lifters if no other possible causes remain.

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: When the PCM recognizes a problem with the Solenoid Control circuit. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 655

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Scheme 659

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. NOTE: Diagnose any Deactivation or Oil Pressure DTCs before continuing with this test. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) MDS SOLENOID NO. 6 Turn the ignition off. Gain access to the MDS Solenoid No. 6. Disconnect the MDS Solenoid No. 6 harness connector. Ignition on, engine not running. Turn off all accessories. Using a 12-volt test light connected to the (Z42) Ground circuit, probe the (K453) MDS Solenoid No. 6 Control circuit. With a scan tool, actuate the MDS Solenoid No. 6. NOTE: The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. Does the 12-volt test light flash on and off? Yes Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. If OK, replace the MDS Solenoid No. 6. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
3. 3) (Z42) GROUND CIRCUIT OPEN Turn the ignition off. Using a 12-volt test light connected to the 12-volts, probe the (Z42) Ground circuit in the MDS Solenoid No. 6 harness connector. Does the test light illuminate brightly? Yes Go to 4) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (K453) MDS SOLENOID CONTROL NO. 6 CIRCUIT SHORTED TO VOLTAGE Disconnect the C2 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K453) MDS Solenoid No. 6 Control circuit in the MDS Solenoid No. 6 connector. Is there any voltage present? Yes Repair the short to voltage in the (K453) MDS Solenoid No. 6 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) .
5. 5) (K453) MDS SOLENOID NO. 6 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Measure the resistance between ground and the (K453) MDS Solenoid No. 6 Control circuit in the MDS Solenoid No. 6 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K453) MDS Solenoid No. 6 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K453) MDS SOLENOID NO. 6 CONTROL CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K453) MDS Solenoid No. 6 Control circuit from the MDS Solenoid No. 6 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K453) MDS Solenoid No. 6 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Solenoid and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched, or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: The MDS fails to engage for cylinder 6. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 660

Scheme 661

Scheme 662

Scheme 663

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) CHECKING PCM CONTROL SIDE FOR THE MDS SOLENOID (C112) Turn the ignition off. Disconnect the C112 harness connector. Using a 12-volt test light, jumper from the (Z42) Ground Circuit and the (K453) MDS Solenoid No. 6 Control Circuit in the C112 harness connector (PCM side). Turn the ignition on. With the scan tool, actuate the MDS Solenoid No. 6. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. Does the 12-volt test light illuminate accordingly? Yes Go to 3) . No Go to 4) .
3. 3) MDS SOLENOID RESISTANCE Turn the ignition off. Measure the resistance between the (Z42) Ground Circuit and the (K453) MDS Solenoid No. 6 Control circuit in the C112 harness connector (MDS side). NOTE: It is important to follow the below temp/resistance values to ensure an accurate reading. MDS SOLENOID RESISTANCE TEMPERATURE VALUE ± -7° C (20° F) RESISTANCE (OHMS) ±.25 ohms -18° C (0° F) 8.8 ohms 0° C (32° F) 9.5 ohms 20° C (68° F) 10.3 ohms 38° C (100° F) 11 ohms 66° C (150° F) 12.2 ohms 93° C (200° F) 13.4 ohms 121° C (250° F) 14.4 ohms 149° C (300° F) 15.6 ohms Is the resistance within an acceptable range? Yes Go to 7) . No Visually and Physically inspect the wiring harness between the C112 connector and the MDS Solenoid connector. Repair as necessary. If OK, replace the MDS Solenoid in accordance with the Service Information.
4. 4) (Z42) GROUND CIRCUIT OPEN (PCM SIDE) Turn the ignition off. Using a 12-volt test light connected to 12-volts, probe the (Z42) Ground circuit in the C112 harness connector (PCM side). Does the test light illuminate brightly? Yes Go to 5) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) (K453) MDS SOLENOID NO. 6 CONTROL CIRCUIT SHORTED TO GROUND (PCM SIDE) Turn the ignition off. Disconnect the C2 PCM harness connector. Measure the resistance between ground and the (K453) MDS Solenoid No. 6 Control circuit in the C112 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K453) MDS Solenoid No. 6 Control circuit between the PCM harness connector and the C112 harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K453) MDS SOLENOID NO. 6 CONTROL CIRCUIT OPEN (PCM SIDE) CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K453) MDS Solenoid No. 6 Control circuit from the C112 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Replace and program the Powertrain Control Module in accordance with the service information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Repair the open in the (K453) MDS Solenoid No. 6 Control circuit between the C112 harness connector and the PCM harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) MDS SOLENOID 6 Turn the ignition off. Remove the Intake Manifold per Service Information. Reconnect the C2 PCM harness connector. Turn the ignition on. With the scan tool actuate the MDS Solenoid 6. Can you feel and hear the Solenoid Actuating? Yes Go to 8) . No Remove the Solenoid (1) and check for any debris that may be blocking the oil passages (3) to the Solenoid. If the passages are clogged, clean the passages and replace the MDS Solenoid 6. If the passages are not clogged with debris, replace the MDS Solenoid 6.
8. 8) OIL PASSAGES RESTRICTED Turn the ignition off. Remove both Solenoids on Bank 2 of the engine block. Remove the Bank 2 Cylinder Head per Service Information. Remove the Lifters from the right engine bank. Inspect the oil passages to the Solenoids and from the Solenoids to the lifters. Are the passages blocked? Yes Clean the oil passages as necessary. If the entire engine is restricted disassembly of the entire engine block may be necessary. No Replace both sets of lifters if no other possible causes remain.

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: When the PCM recognizes a problem with the Solenoid Control circuit. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 664

Scheme 665

Scheme 666

Scheme 667

Scheme 668

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. NOTE: Diagnose any Deactivation or Oil Pressure DTCs before continuing with this test. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) MDS SOLENOID NO. 7 Turn the ignition off. Gain access to the MDS Solenoid No. 7. Disconnect the MDS Solenoid No. 7 harness connector. Ignition on, engine not running. Turn off all accessories. Using a 12-volt test light connected to the (Z42) Ground circuit, probe the (K454) MDS Solenoid No. 7 Control circuit. With a scan tool, actuate the MDS Solenoid No. 7. NOTE: The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. With a scan tool, actuate the MDS Solenoid No. 7. Does the 12-volt test light illuminate accordingly? Yes Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. If OK, replace the MDS Solenoid No. 7. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 3) .
3. 3) (Z42) GROUND CIRCUIT OPEN Turn the ignition off. Using a 12-volt test light connected to the 12-volts, probe the (Z42) Ground circuit in the MDS Solenoid No. 7 harness connector. Does the test light illuminate brightly? Yes Go to 4) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
4. 4) (K454) MDS SOLENOID NO. 7 CONTROL CIRCUIT SHORTED TO VOLTAGE Disconnect the C3 PCM harness connector. Ignition on, engine not running. Measure the voltage on the (K454) MDS Solenoid No. 7 Control circuit in the MDS Solenoid No. 7 harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K454) MDS Solenoid No. 7 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) .
5. 5) (K454) MDS SOLENOID NO. 7 CONTROL CIRCUIT SHORTED TO GROUND Turn the ignition off. Measure the resistance between ground and the (K454) MDS Solenoid No. 7 Control circuit in the MDS Solenoid No. 7 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K454) MDS Solenoid No. 7 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K454) MDS SOLENOID NO. 7 CONTROL CIRCUIT OPEN CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K454) MDS Solenoid No. 7 Control circuit from the MDS Solenoid No. 7 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Go to 7) . No Repair the open in the (K454) MDS Solenoid No. 7 Control circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) POWERTRAIN CONTROL MODULE (PCM) Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Solenoid and the Powertrain Control Module (PCM). Look for any chafed, pierced, pinched, or partially broken wires. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. Refer to any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: The MDS fails to engage for cylinder 7. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Scheme 669

Scheme 670

Scheme 671

Scheme 672

1. 1) ACTIVE DTC NOTE: Diagnose any Misfire DTCs before continuing. Start the engine and allow it to reach normal operating temperature. WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. NOTE: It may be necessary to test drive the vehicle in order for this DTC to set. With a scan tool, select View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) CHECKING PCM CONTROL SIDE FOR THE MDS SOLENOID (C112) Turn the ignition off. Disconnect the C112 harness connector. Using a 12-volt test light, jumper from the (Z42) Ground Circuit and the (K454) MDS Solenoid No. 7 Control Circuit in the C112 harness connector (PCM side). Turn the ignition on. With the scan tool, actuate the MDS Solenoid No. 7. NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery. Does the 12-volt test light illuminate accordingly? Yes Go to 3) . No Go to 4) .
3. 3) MDS SOLENOID RESISTANCE Turn the ignition off. Measure the resistance between the (Z42) Ground Circuit and the (K454) MDS Solenoid No. 7 Control Circuit in the C112 harness connector (MDS side). NOTE: It is important to follow the below temp/resistance values to ensure an accurate reading. MDS SOLENOID RESISTANCE TEMPERATURE VALUE ± -7° C (20° F) RESISTANCE (OHMS) ±.25 ohms -18° C (0° F) 8.8 ohms 0° C (32° F) 9.5 ohms 20° C (68° F) 10.3 ohms 38° C (100° F) 11 ohms 66° C (150° F) 12.2 ohms 93° C (200° F) 13.4 ohms 121° C (250° F) 14.4 ohms 149° C (300° F) 15.6 ohms Is the resistance within an acceptable range? Yes Go to 7) . No Visually and Physically inspect the wiring harness between the C112 connector and the MDS Solenoid connector. Repair as necessary. If OK, replace the MDS Solenoid in accordance with the Service Information.
4. 4) (Z42) GROUND CIRCUIT OPEN (PCM SIDE) Turn the ignition off. Using a 12-volt test light connected to 12-volts, probe the (Z42) Ground circuit in the C112 harness connector (PCM side). Does the test light illuminate brightly? Yes Go to 5) . No Repair the open in the (Z42) Ground circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
5. 5) (K454) MDS SOLENOID NO. 7 CONTROL CIRCUIT SHORTED TO GROUND (PCM SIDE) Turn the ignition off. Disconnect the C3 PCM harness connector. Measure the resistance between ground and the (K454) MDS Solenoid No. 7 Control circuit in the C112 harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (K454) MDS Solenoid No. 7 Control circuit between the PCM harness connector and the C112 harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 6) .
6. 6) (K454) MDS SOLENOID NO. 7 CONTROL CIRCUIT OPEN (PCM SIDE) CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis. Measure the resistance of the (K454) MDS Solenoid No. 7 Control circuit from the C112 harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes Replace and program the Powertrain Control Module in accordance with the service information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Repair the open in the (K454) MDS Solenoid No. 7 Control circuit between the C112 harness connector and the PCM harness connector. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .
7. 7) MDS SOLENOID 7 Turn the ignition off. Remove the Intake Manifold per Service Information. Reconnect the C3 PCM harness connector. Turn the ignition on. With the scan tool actuate the MDS Solenoid 7. Can you feel and hear the Solenoid Actuating? Yes Go to 8) . No Remove the Solenoid (1) and check for any debris that may be blocking the oil passages (3) to the Solenoid. If the passages are clogged, clean the passages and replace the MDS Solenoid 7. If the passages are not clogged with debris, replace the MDS Solenoid 7.
8. 8) OIL PASSAGES RESTRICTED Turn the ignition off. Remove both Solenoids on Bank 1 of the engine block. Remove the Bank 1 Cylinder Head per Service Information. Remove the Lifters from the right engine bank. Inspect the oil passages to the Solenoids and from the Solenoids to the lifters. Are the passages blocked? Yes Clean the oil passages as necessary. If the entire engine is restricted disassembly of the entire engine block may be necessary. No Replace both sets of lifters if no other possible causes remain.

1. When Monitored: Transition from 8 to 4 cylinder mode.

1. Set Condition: O2 sensor readings on Bank 2 side indicate a lean condition while in 4 cylinder mode. One trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

1. Set Condition: The PCM loses communication over the CAN C Bus circuit. The circuit is continuously monitored. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

1. Set Condition: The PCM doesn't receive a Bus Message from the Transmission Control Module for 7 consecutive seconds. The circuit is continuously monitored. Two Trip fault.

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: With the ignition on. Battery voltage between 10 and 16 volts. IOD fuse installed. FCM is configured correctly.

1. Set Condition: Bus messages not received from the Electric Gear Shift Module (shift lever assembly) for approximately 500 ms.

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

1. Set Condition: The PCM doesn't receive a FDCM message over the CAN C circuit for 7 consecutive seconds. The circuit is continuously monitored. One Trip fault.

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

1. Set Condition: The PCM doesn't receive an ABS message over the CAN C circuit for 7 consecutive seconds. The circuit is continuously monitored. One Trip fault.

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts.

1. Set Condition: The PCM doesn't receive a FCM message over the CAN C circuit for 7 consecutive seconds. The circuit is continuously monitored. One Trip fault.

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

1. Set Condition: The PCM doesn't receive a Cluster message over the CAN C circuit for 7 consecutive seconds. The circuit is continuously monitored.

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

1. Set Condition: The PCM doesn't receive a SKREEM message over the CAN C circuit for 7 consecutive seconds. The circuit is continuously monitored.

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

1. Set Condition: The PCM doesn't receive a SKREEM message over the CAN C circuit for 7 consecutive seconds. The circuit is continuously monitored. One Trip fault.

Refer to DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.

1. When Monitored: Ignition on.

1. Set Condition: When the PCM does not receive a fuel level signal from the FCM over the CAN C circuit. The circuit is constantly monitored. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

The fuel level signal is a direct input to the Cluster. The fuel level signal is sent to the FCM over the CAN B bus circuit. The NGC receives the fuel level signal from the FCM over the CAN C bus circuit.

1. When Monitored: Ignition on.

1. Set Condition: The PCM doesn't receive the ambient temperature signal over the CAN C bus from the FCM. The circuit is continuously monitored. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

The ambient temperature sensor signal is a direct input to the FCM. The FCM sends the PCM the ambient temperature signal over the CAN C bus.

1. When Monitored: Ignition on.

1. Set Condition: The PCM doesn't receive a vehicle speed signal from the Anti-lock brake Module over the CAN C bus. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

The PCM receives the vehicle speed signal over the CAN C bus from the Anti-lock Brake Module.

1. When Monitored: Ignition on.

1. Set Condition: The PCM doesn't receive an odometer reading from the cluster through the FCM over CAN C. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

The PCM receives odometer readings from the Front Control Module over CAN C. The FCM gets the odometer readings from the Cluster Module over CAN B. U0001-CAN C BUS, and U0141-LOST COMMUNICATION WITH FCM may also set.

1. When Monitored: Ignition on.

1. Set Condition: The PCM doesn't receive the A/C Pressure signal over the CAN C bus from the FCM. The circuit is continuously monitored. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

The A/C Pressure Transducer signal is a direct input to the FCM. The FCM sends the PCM the A/C pressure signal over the CAN C bus.

1. When Monitored: Ignition on.

1. Set Condition: The PCM doesn't receive a vehicle speed signal from the Anti-lock brake Module over the CAN C bus. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

The PCM receives the vehicle speed signal over the CAN C bus from the Anti-lock Brake Module.

1. When Monitored: Ignition on.

1. Set Condition: The fuel level message the PCM is receiving is implausible. The circuit is continuously monitored. One Trip fault.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .

The Front Control Module isn't receiving a fuel level signal over CAN B from the Cluster Module. The FCM has to send the PCM a fuel level signal over CAN C. The signal the FCM sends over CAN C is implausible.

Scheme 673

Scheme 674

Scheme 675

1. 1) ACTIVE DTC Ignition on, engine not running. With a scan tool, View DTCs. Is the DTC Active at this time? Yes Go to 2) . No Refer to «INTERMITTENT CONDITION»(ref-288287-S02739760862008062000000) Diagnostic Procedure.
2. 2) CAN B BUS HARDWARE DTCS ALSO ACTIVE With a scan tool check for DTCs in the FCM. Are any CAN B Hardware related DTCs active at this time? Yes Refer to «DIAGNOSIS AND TESTING»(ref-288232-S40396979612008062000000) for the appropriate diagnostic procedures. No Go to 3) .
3. 3) (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO VOLTAGE Turn the ignition off. Disconnect the C1 Cluster harness connector. Disconnect the Fuel Pump Module harness connector. Ignition on, engine not running. Measure the voltage on the (N4) Fuel Level Signal circuit in the Fuel Pump Module harness connector. Is there any voltage present? Yes Repair the short to voltage in the (N4) Fuel Level Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 4) .
4. 4) (N4) FUEL LEVEL SIGNAL CIRCUIT SHORTED TO GROUND Turn the ignition off. Measure the resistance between ground and the (N4) Fuel Level Signal circuit in the Fuel Pump Module harness connector. Is the resistance below 100 ohms? Yes Repair the short to ground in the (N4) Fuel Level Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Go to 5) .
5. 5) (N4) FUEL LEVEL SIGNAL CIRCUIT OPEN Measure the resistance of the (N4) Fuel Level Signal circuit from the Fuel Pump Module harness connector to the C1 Cluster harness connector. Is the resistance below 5.0 ohms? Yes Replace and program the Powertrain Control Module per Service Information. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) . No Repair the open in the (N4) Fuel Level Signal circuit. Perform «POWERTRAIN VERIFICATION TEST»(ref-288299-S34942598282008062000000) .