The function diagram for the MAT sensor includes the following:
• MAT sensor
• Exhaust Gas Recirculation (EGR)
• Electronic Control Module (ECM)
• ENGINE lamp (amber)
Function
The MAT sensor is a thermistor sensor installed right of the MAP sensor in the intake manifold. The ECM supplies a 5 V reference signal which the MAT sensor uses to produce an analog voltage that indicates temperature. The MAT sensor changes resistance when exposed to different temperatures.
As air temperature decreases, the resistance of the thermistor increases. This causes the signal voltage to increase. As air temperature increases, the resistance of the thermistor decreases. This causes the signal voltage to decrease.
The MAT sensor provides a feedback signal to the ECM indicating manifold air temperature. The ECM monitors the MAT signal to determine if the temperature is satisfactory. During engine operation, if the ECM recognizes that the MAT signal is greater or less than the expected value it will set a Diagnostic Trouble Code (DTC).
