Circuit/System Description

The driver and front passenger seats are heated using electric heater elements located in the seat cushions and seat backs. Battery voltage to the heater elements is controlled by the heated seat modules using inputs from the heated seat switches and the heated seat thermistors. When the heated seat switch is in the high or low position, ignition voltage is supplied through the heated seat switch signal circuit to the module. Voltage to the high/low switch signal circuit is reduced by the resistors within the heated seat switch and high or low seat heater operation is determined by the voltage level of the high/low signal circuit to the heated seat module. The seat temperature is regulated by the module using an input from the thermistor located in the seat cushion. The thermistor is a temperature sensitive variable resistor and the module determines the seat cushion temperature by monitoring the signal voltage supplied to the thermistor. When the desired seat temperature has been reached the module will open and close the supply voltage to the heater elements as necessary in order to maintain the seat temperature. Ignition voltage is supplied to the heated seat switch from the HTD SEATS 10A fuse in the I/P fuse block. Battery voltage is supplied to the heated seat control module form the HTD SEATS 20A fuse in the underhood fuse block. Ground for the switches and module is at G301.