No Response From ECM (SCI Only) Diesel Only
NOTE:
After making any repairs, perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- See CHECKING PCM POWER & GROUND CIRCUITS . If the vehicle passed this test, go to the next step. If the vehicle did not pass this test, repair as necessary.
- Turn the ignition off. Disconnect the ECM harness connectors. See Figure. Disconnect the DRBIII from the DLC. Measure the resistance between ground and the SCI transmit circuit. If the resistance is below 5.0 ohms, repair the SCI transmit circuit for a short to ground. If the resistance is above 5.0 ohms, go to the next step.
- Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the DRBIII from the DLC. Turn the ignition on. Measure the voltage of the SCI transmit circuit. If the voltage is above 1.0 volt, repair the SCI transmit circuit for a short to voltage. If the voltage is below 1.0 volt, go to the next step.
- Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the DRBIII from the DLC. Measure the resistance of the SCI transmit circuit between the ECM connector and the DLC. If the resistance is below 5.0 ohms, replace and program the engine control module. See POWERTRAIN CONTROL MODULE under REMOVAL & INSTALLATION. See POWERTRAIN CONTROL MODULE (PCM) under PROGRAMMING. If the resistance is above 5.0 ohms, repair the SCI transmit circuit for an open.