Theory Of Operation

The Comfort Rear Seat Module (CRSM) uses a Pulse Width Modulation (PWM) signal to provide a variable power to the heated seat element in a parallel circuit to the seat cushion and back. The CRSM regulates the heated seat element temperature by monitoring a signal from the temperature sensor located within each seat heater element. As the temperature of the sensor decreases, the sensor resistance increases producing a higher voltage on the signal circuit. As the temperature of the sensor increases, the sensor resistance decreases producing a lower voltage on the signal circuit. The CSRM provides a sensor ground and a low current, 5-volt signal circuit to the Temperature Sensors.