Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the fuel level sensor.
- Ignition OFF, test for less than 10 Ω between the low reference circuit terminal listed below and ground.
- Low Reference Terminal B (5.3L)
- Low Reference Terminal C (4.3L, 4.8L or 6.0L)
- Low Reference Terminal C (6.6L Diesel)
- If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
- Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal and the low reference circuit terminal listed below. Verify the scan tool Fuel Tank Level Remaining parameter display is greater than 98 percent.
- Signal Terminal C (5.3L)
- Low Reference Terminal B (5.3L)
- Signal terminal B (4.3L, 4.8L or 6.0L)
- Low Reference Terminal C (4.3L, 4.8L or 6.0L)
- Signal Terminal B (6.6L Diesel)
- Low Reference Terminal C (6.6L Diesel)
- If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the fuel level sensor.