Manifold Air Temperature (MAT) Sensor (2.5L & 4.3L Turbo)

MAT sensor is a thermistor (temperature sensitive resistor) mounted in the intake manifold. Low intake air temperature produces high internal sensor resistance, while high temperature causes low internal sensor resistance. The ECM supplies and monitors a 5-volt signal to sensor through a pull-down resistor in ECM.

MAT sensor, also known as an intake air temperature sensor, allows ECM to determine intake air temperature. ECM uses signal to delay EGR until intake air temperature reaches about 40°F (5°C). If intake air temperature becomes excessively high, ECM compensates by slightly retarding ignition timing. After a vehicle has sat overnight, MAT and CTS signals (resistance and temperature) should be close to same reading. Failure in MAT sensor circuit should set a related trouble code.