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 DIAGNOSTIC TROUBLE CODE DEFINITIONS
in SELF-DIAGNOSTICS - 3.1L CENTURY, GRAND PRIX & MALIBU 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. See Fig 1. Using DVOM, measure resistance between terminals 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.
Courtesy of GENERAL MOTORS CORP.