BMW 13621725323 Intake Air Temperature Sensor

The Intake Manifold Temperature Sensor (IAT) sensor, an NTC type sensor, measures incoming air temperature. The Engine Control Module (ECM) uses it to adjust fuel injection and ignition timing. The sensor's location varies with engine type. A BMW service tester or Data Scan Tool (DST) can test the sensor. For engines with a vane type Mass Air Flow (MAF) sensor, the Intake Manifold Temperature Sensor is in the MAF housing. Check for a 5 volt signal between terminal No.1 and ground. If absent, check for an open circuit. Check resistance between terminals Nos. 2 and 3, which should change with temperature. For 1996-98 models, the Intake Manifold Temperature Sensor is separate, located in the intake manifold or upper air filter housing. Check for a 5 volt signal between the reference signal connector and ground. If absent, check for an open circuit. Check resistance between the IAT terminals, which should decrease as air temperature increases. Follow specific procedures to remove and install the sensor.