FixVault

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the IAT sensor.
  2. Ignition OFF, test for less than 5 ohm of resistance between the low reference circuit terminal E 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 engine control module (ECM).
  3. Ignition ON, verify the scan tool IAT parameter is less than -39°C (-38°F).
    • If greater than the specified range, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the ECM.
  4. Install a 3A fused jumper wire between the signal circuit terminal D and a good ground. Verify the scan tool IAT parameter is greater than 149°C (300°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.
  5. If all circuits test normal, test or replace the IAT sensor.