Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the ECM.
- Connect the J 33431-C
to the engine coolant temperature gage output signal circuit terminal XK67 at the ECM harness connector and ground.
- Ignition ON, set the J 33431-C
to generate a speedometer signal. The engine coolant temperature gage should change.
- If the gage changes, replace the ECM.
- If the gage does not change, test and repair the signal circuit for the following conditions:
- An open
- A short to ground
- A short to voltage
- A high resistance
- If all circuits test normal, replace the IPC.