Fleetwood FWD V8-300 4.9L (1993)
Manifold Air Temperature (MAT) Sensor: Description and Operation
Intake Air Temperature Sensor
Sensor Circuit
The Manifold Air Temperature (MAT) sensor is mounted in the upper intake manifold, downstream of the throttle body. This sensor measures the
temperature of the air/fuel mixture in the intake manifold, and sends this information to the PCM/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 PCM/ECM. The MAT sensor provides intake air temperature
information to the PCM/ECM for the use in calculating intake air density.
The PCM/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.
