Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the B34 engine coolant temperature sensor.
- Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 Ω between the low reference circuit terminal A 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 K20 engine control module.
- Ignition ON, verify the scan tool ECT Sensor parameter is colder than -40°C (-40°F).
- If warmer than the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 engine control module.
- Install a 3 A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool ECT Sensor parameter is warmer than 150°C (302°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 K20 engine control module.
- If all circuits test normal, test or replace the B34 engine coolant temperature sensor.