Diagnostic Procedure
WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
DIAGNOSTIC PROCEDURES - NO RESPONSE FROM ECM (DIESEL ONLY)
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 | Perform SYMPTOM CHECKING ECM POWER AND GROUND CIRCUITS . Did the vehicle pass this test? Yes --> Go To 2 No --> Repair as necessary. Perform ROAD TEST VERIFICATION - VER-2 . |
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| 2 | Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the DRB from the DLC. Measure the resistance between ground and the SCI Transmit circuit. Is the resistance below 5.0 ohms? Yes --> Go To 3 No --> Go To 6 |
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| 3 | Turn the ignition off. Disconnect the TCM harness connector (if equipped).
NOTE:
If vehicle is not equipped with a TCM, answer yes to the question. Measure the resistance between ground and the SCI Transmit circuit. Is the resistance below 5.0 ohms? Yes --> Go To 4 No --> Replace the Transmission Control Module in accordance with the service information. Perform ROAD TEST VERIFICATION - VER-2 . |
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| 4 | Turn the ignition off. Disconnect the FCM harness connector. Measure the resistance between ground and the SCI Transmit circuit. Is the resistance below 5.0 ohms? Yes --> Go To 5 No --> Replace the Front Control Module in accordance with the service information. Perform ROAD TEST VERIFICATION - VER-2 . |
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| 5 | Turn the ignition off. Disconnect the Antilock Brake Module 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. Is the resistance below 5.0 ohms? Yes --> Repair the SCI Transmit circuit for a short to ground. Perform ROAD TEST VERIFICATION - VER-2 . No --> Replace the Antilock Brake Module in accordance with the service information. Perform ROAD TEST VERIFICATION - VER-2 . |
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| 6 | Turn the ignition off. Disconnect the DRB from the DLC. Disconnect the ECM harness connectors. Disconnect the TCM harness connector (if equipped). Disconnect the Antilock Brake Module 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 ROAD TEST VERIFICATION - VER-2 . No --> Go To 7 |
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| 7 | Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the DRB from the DLC. Measure the resistance of the SCI Transmit circuit between the ECM connector and the DLC. Is the resistance below 5.0 ohms? Yes --> Replace and program the Engine Control Module in accordance with the Service Information. Perform ROAD TEST VERIFICATION - VER-2 . No --> Repair the SCI Transmit circuit for an open. Perform ROAD TEST VERIFICATION - VER-2 . |
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