Circuit/System Testing (3.8L, 5.3L, 6.0L, 6.2L, 7.0L Engines)
- Ignition OFF, disconnect the harness connector at the fuel level sensor.
- Ignition OFF, test for less than 1 ohm between the fuel level sensor low reference circuit terminal C and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the PCM.
- Install a Signal Generator and Instrument Panel Tester between the fuel level sensor signal circuit terminal B and the fuel level sensor low reference circuit terminal C.
- Ignition ON, vary the signal generator resistance between 40 and 250 ohms. Verify that the scan tool Fuel Tank Level Remaining parameter displays a range that varies between 5 and 95 percent as the signal generator resistance changes.
- If not within the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the PCM.
- If all circuits test normal, test or replace the fuel level sensor.