Seville V8-273 4.5L (1989)
Manifold Air Temperature (MAT) Sensor: Description and Operation
Intake Air Temperature Sensor
The Manifold Air Temperature (MAT) sensor is mounted in the intake manifold, in front of the throttle body. This sensor measures the temperature of
the air/fuel mixture in the intake manifold, and sends this information to the Electronic Control Module (ECM). The MAT sensor is a thermistor whose
resistance changes as a function of temperature. 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 reference or signal voltage from the ECM. The MAT sensor provides intake air temperature
information to the ECM for the use in calculating intake air density. The ECM uses MAT, MAP, and engine speed to calculate the quantity of air
flowing into the engine. A failure in the MAT sensor circuit should set a code E037 or E038.
