Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the ECT sensor.
- Ignition ON, clear the DTC information with a scan tool.
- Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 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.
- Ignition ON, verify the scan tool ECT sensor parameter is at -40°C (-40°F).
- If greater than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
- Ignition ON, clear the DTC information with a scan tool.
- Install a 1A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the ECT sensor parameter is greater than 128°C (262°F).
- 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 ECT sensor.
IMPORTANT:
If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.