Intake Air Temperature Sensor
- Manufacturer does not provide testing procedures for many individual systems and components. A malfunction in Intake Air Temperature (IAT) sensor circuit can set a DTC. For testing procedures and specifications, perform related DTC testing procedure. See SELF-DIAGNOSTICS - 3.8L BONNEVILLE, GRAND PRIX, IMPALA, LESABRE, MONTE CARLO, PARK AVENUE & REGAL article. An out-of-calibration IAT sensor may not set a DTC. Use the following procedure to test sensor calibration.
- Disconnect IAT sensor harness connector. Using DVOM, measure resistance of IAT sensor at specified temperatures. See TEMPERATURE VS. RESISTANCE table. Resistance should be high when air temperature is cold and drop as air temperature warms. With vehicle sitting overnight, ECT sensor and IAT sensor should have close to the same resistance reading. If resistance is not within specification, replace IAT sensor.