ECM DTC EO37: Shorted Mat Sensor Circuit: Description

The MAT sensor is a thermistor, or variable resistor, that varies resistance based on temperature. As the temperature of the sensor increases, resistance decreases. High temperature will result in low signal voltage. Code EO37 sets when the ECM sees a MAT sensor reading of 148°C when the coolant is less than 100°C. The MAT sensor connector is located on the right rear top of engine behind the alternator.