Riviera V6-231 3.8L VIN C SFI (1989)
Intake Air Temperature Sensor: Description and Operation
Intake Air Temperature Sensor
The Manifold Air Temperature (MAT) sensor is a thermistor whose resistance changes as a function of the temperature of air entering the engine. When
the temperature is low, the resistance is high. Resistance decreases as the temperature increases. The MAT sensor is a two wire sensor that receives a 5.0
volt signal from the ECM through a resister in the ECM and measures voltage output. The voltage will be high when the incoming air is cold, and low
when the air is hot. The MAT sensor provides intake air temperature information to the ECM for the use in calculating compensation of the MAF sensor
signal based on temperature. The ECM uses MAT, MAF, and engine speed to calculate the quantity of air flowing into the engine. A failure in the MAT
sensor circuit should set a code E023 or E025.
