Air Temperature Sensor ( Ambient / Intake ): Description and Operation

Intake Air Temperature Sensor V8:

DESCRIPTION

The Intake Air Temperature (IAT) sensor is a thermocouple that supplies the Motronic control module with the temperature of the intake air in the intake manifold.

This temperature signal is used for fuel injection quantity, ignition timing, knock regulation. If the intake air temperature exceeds a predetermined level, the Motronic control module will retard the ignition timing.

SELF DIAGNOSIS

The IAT Sensor Signal is monitored by the ECM and sets a fault code if the signal is outside of proper range.

Diagnostic Trouble Code # 00523 is displayed on the VAG 1551 scan tool.

Blink Code # 2322 is displayed using blink code extraction.

SIGNAL SUBSTITUTION

If the sensor should fail, the ignition timing is retarded and a replacement value of 68°F (20°C) is used.