Manifold Air Temperature (MAT) Sensor

The MAT sensor (may also be referred to as an intake air temperature 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 resistor in ECM. By monitoring this voltage, ECM determines manifold air temperature. After a vehicle has been parked overnight, MAT and CTS signals (resistance and temperature) should be close to same reading. Failure in MAT sensor circuit (open or short to ground) will cause monitored voltage to swing high or low and should set a related trouble code.