Circuit/System Testing
- Ignition OFF, disconnect the ambient air temperature sensor.
- Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit and ground.
- If greater than 1.0 ohm, test the ground circuit for an open/high resistance.
- Ignition ON, verify the scan tool Ambient Air Temp. Sensor parameter is greater than 4.7 volts.
- If less than 4.7 volts, test the signal circuit for a short to ground.
- Ignition ON, install a 3-amp fused jumper wire between the signal circuit and ground. Verify the scan tool Ambient Air Temp. Sensor parameter is less than 0.4 volts.
- If greater than 0.4 volts, test the signal circuit for an open/high resistance. If the circuit tests normal replace the BCM.
- If the scan tool parameter is normal, replace the ambient air temperature sensor.