Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the fuel level sensors. Install a signal generator and instrument panel tester between the signal circuit and the low reference circuit.
- Ignition ON, vary the resistance on the signal generator from 40 to 250 ohms. Verify that the scan tool Fuel Level parameter displays the correct fuel level.
- If the fuel level is incorrect, test the signal circuit and the low reference circuit for an open/high resistance. If the circuits test normal, replace the ECM/PCM.
- If all circuits test normal, test or replace the fuel level sensors.