Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the primary and secondary fuel level sensors. Jumper the 2 signal circuits together and then install a signal generator and instrument panel tester between the signal circuits and the low reference circuit.
- Ignition ON, vary the resistance on the signal generator from 40-250 ohms. Verify that the scan tool Fuel Tank Level Remaining parameter displays the correct fuel level percent.
- If the fuel level percent is incorrect, test both signal circuits and the low reference circuit for an open/high resistance. If the circuits test normal, replace the ECM.
- Ignition ON, vary the resistance on the signal generator from 40-250 ohms and monitor the fuel gage.
- If the gage is incorrect, replace the IPC.
- If all circuits test normal, test or replace either the primary or secondary fuel level sensor.