Diagnostic Procedure
DIAGNOSTIC INFORMATION AND PROCEDURES - NO RESPONSE FROM PCM (PCM SCI ONLY) - NGC
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 | Perform the symptom Checking PCM Power and Ground Circuits in POWERTRAIN DIAGNOSTIC PROCEDURES
article.
NOTE:
With the DRBIII® in the generic scan tool mode, attempt to communicate with the PCM.
NOTE:
If the DRBIII® can communicate with the PCM in the generic scan tool mode, it may not be necessary to perform this step. Did the vehicle pass this test? Yes --> Go To 2 No --> Repair as necessary. Perform POWERTRAIN VERIFICATION TEST VER - 1 . |
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| 2 | Turn the ignition off. Disconnect the PCM harness connectors. Disconnect the DRB from the DLC. Measure the resistance between ground and the SCI Transmit circuit at the DLC (cav7). Is the resistance below 5.0 ohms? Yes --> Go To 3 No --> Go To 4 |
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| 3 | Turn the ignition off. Disconnect the CAB harness connector (if equipped).
NOTE:
If vehicle is not equipped with antilock brakes, answer yes to the question. Measure the resistance between ground and the SCI Transmit circuit at the DLC (cav7). Is the resistance below 5.0 ohms? Yes --> Repair the SCI Transmit circuit for a short to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 . No --> Replace the Controller Antilock Brake in accordance with the service information. Perform POWERTRAIN VERIFICATION TEST VER - 1 . |
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| 4 | Turn the ignition off. Disconnect the DRB from the DLC. Disconnect the PCM harness connectors. Disconnect the CAB harness connector (if equipped). Turn the ignition on. Measure the voltage of the SCI Transmit circuit at the DLC (cav 7). Is the voltage above 1.0 volt? Yes --> Repair the SCI Transmit circuit for a short to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 . No --> Go To 5 |
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| 5 | Turn the ignition off. Disconnect the DRB from the DLC. Disconnect the PCM harness connectors. Turn the ignition on. Measure the voltage of the SCI Receive circuit at the DLC (cav 12). Is the voltage above 1.0 volt? Yes --> Repair the SCI Receive circuit for a short to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 . No --> Go To 6 |
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| 6 | Turn the ignition off. Disconnect the DRB from the DLC. Disconnect the PCM harness connectors. Measure the resistance between the SCI Transmit circuit and the SCI Receive circuit at the DLC (cavs 7 and 12). Is the resistance below 5.0 ohms? Yes --> Repair the short between the SCI Transmit and the SCI Receive circuits. Perform POWERTRAIN VERIFICATION TEST VER - 1 . No --> Go To 7 |
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| 7 | Turn the ignition off. Disconnect the PCM harness connectors. Disconnect the DRB from the DLC. Measure the resistance between ground and the SCI Receive circuit at the DLC (cav12). Is the resistance below 5.0 ohms? Yes --> Repair the SCI Receive circuit for a short to ground. Perform POWERTRAIN VERIFICATION TEST VER - 1 . No --> Go To 8 |
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| 8 | Turn the ignition off. Disconnect the PCM harness connectors. Disconnect the DRB from the DLC.
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 SCI Receive circuit from the DLC (cav 12) to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes --> Go To 9 No --> Repair the SCI Receive circuit for an open. Perform POWERTRAIN VERIFICATION TEST VER - 1 . |
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| 9 | Turn the ignition off. Disconnect the PCM harness connectors. Disconnect the DRB from the DLC.
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 SCI Transmit circuit from the DLC (cav 7) to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes --> Go To 10 No --> Repair the SCI Transmit circuit for an open. Perform POWERTRAIN VERIFICATION TEST VER - 1 . |
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| 10 | If there are no possible causes remaining, view repair. Repair Replace and program the Powertrain Control Module in accordance with the Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 1 . |
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