The heated seats system consists of 4 heated seats; 2 in the front and 2 in the rear. Each heated seat consists of the following components:

The driver door module (DDM), passenger front door module (PFDM), left rear door module (LRDM), and right rear door module (RRDM) are also involved in the operation of the heated seats.

Battery positive voltage is supplied at all times to the heated seat modules through the battery positive voltage circuit and the appropriate HTDST Fuse located in the rear fuse block. Battery positive voltage is also supplied to the heated seat modules through the ignition 3 voltage circuit and the IGN 3 Fuse located in the rear fuse block. The system will operate only with the ignition switch in the ON position. The driver and front passenger heated seat modules are grounded through the module ground circuits and G302. The left rear and right rear heated seat modules are grounded through the module ground circuits and G301.

Each heated seat is controlled by a separate heated seat switch. Battery positive voltage is supplied to the heated seat switch by the appropriate door module.

When the heated seat is off and the heated seat switch HEAT/OFF button is pressed once, the door module supplies a ground through the heated seat high temperature indicator control circuit to the heated seat switch, illuminating the HI temperature indicator. When the switch is pressed a second time, the door module turns off the HI temperature indicator, then supplies a ground through the heated seat medium temperature indicator control circuit to the heated seat switch, illuminating the MED temperature indicator. When the switch is pressed a third time, the door module turns off the MED temperature indicator, then supplies a ground through the heated seat low temperature indicator control circuit to the heated seat switch, illuminating the LOW temperature indicator. After the switch is pressed the fourth time, the door module removes the ground, turning off the LOW temperature indicator.

When the BACK ONLY button is pressed once, the door module supplies a ground through the heated seat back only indicator control circuit to the heated seat switch, illuminating the BACK ONLY mode indicator. When the switch is pressed a second time the door module cancels the back only mode and removes the ground, turning off the BACK ONLY mode indicator.

There are 2 modes available for heated seat operation; seat cushion and seat back heat, or seat back only heat. When a heated seat temperature signal request is received, the heated seat module will activate both the seat cushion and seat back heating elements. When the heated seat BACK ONLY mode button is pressed once, the heated seat module will deactivate the seat cushion heating element and leave the seat back heating element on. Press the heated seat BACK ONLY button a second time and the heated seat module will reactivate the seat cushion heating element.

When the heated seat switch HEAT/OFF button is pressed, battery positive voltage is momentarily applied through the switch contacts and the heated seat temperature switch signal circuit of the door module. In response to this signal, the door module momentarily sends a 35 millisecond one shot pulse signal that is pulled low through the heated seat temperature signal circuit of the heated seat module. The heated seat module then applies or removes battery positive voltage through the heated seat element supply voltage to the seat heating elements. The heated seat module counts the signals received from the door module to determine the requested temperature level.

When the heated seat is ON and the BACK ONLY mode button is pressed, battery positive voltage is momentarily applied through the switch contacts and the heated seat back only mode signal circuit of the door module. In response to this signal, the door module momentarily sends a 35 millisecond one shot pulse signal that is pulled low through the heated seat back only mode signal circuit of the heated seat module. In response to this signal, the heated seat module then opens the ground path of the seat cushion heating element through the element control circuit.

The heated seat system is designed to warm the seat cushion and seat back to approximately 42°C (107.6°F) when in the high position, 39.5°C (103°F) when in the MED position, and 37°C (98.6°F) when in the low position. The heated seat module monitors the seat temperature through the temperature sensor signal circuit and the temperature sensors (thermistor) that are located in the seat cushion and seat back. The temperature sensor is a variable resistor, it's resistance varies as the temperature of the seat changes. When the temperature sensor resistance indicates to the heated seat module that the seat has reached the desired temperature, the module opens the ground path of the seat heating elements through the heated seat element control circuit. The module will then cycle the element control circuit open and closed in order to maintain the desired temperature.