Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the IAT sensor 2.
- Ignition OFF, all vehicles systems OFF, this may take up to for 2 min, test for less than 5 Ω between the low reference circuit terminal B 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 IAT sensor 2 parameter is colder than -39°C (-38°F).
- If warmer than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
- Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool IAT sensor 2 parameter is warmer than 130°C (266°F).
- If colder 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 IAT sensor 2.