Circuit/System Testing
- Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the fuel filter assembly.
- Test for less than 5 ohms between the low reference circuit terminal 6 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 ECM.
- Install the MAIN fuse. Ignition ON, verify the scan tool fuel temperature sensor parameter is at 5 volts.
- If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
- Install a 1A fused jumper wire between the signal circuit terminal 5 and ground. Verify the scan tool fuel temperature sensor parameter is at 0 volts.
- If greater 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 temperature sensor.
NOTE:
Do NOT use the low reference circuit in the component harness connector for this test. Damage to the control module may occur due to excessive current draw.
IMPORTANT:
If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.