Intake Air Temperature (IAT) Sensor

If an IAT sensor-related code is present, see the TESTS W/CODES article. An out-of-calibration sensor may not set a trouble code. Use following procedure to test calibration. Disconnect IAT sensor harness connector. Connect ohmmeter between sensor terminals. Sensor resistance should be as specified. See IAT SENSOR RESISTANCE  table. With vehicle sitting overnight, IAT sensor and coolant sensor should have close to the same resistance reading.