Circuit/System Testing
- Ignition OFF, disconnect the MAF/IAT sensor.
- Test for less than 5 ohms between the low reference circuit terminal 5 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the circuit tests normal, replace the PCM.
- Ignition ON, verify that the IAT sensor parameter is at -40°C (-40°F).
- If greater than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the PCM.
- Install a 3A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 5. Verify the IAT sensor parameter is greater than 139°C (280°F).
- If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.
- If all circuits test normal, test or replace the IAT sensor.