Heated Seats (Service Information): Operation

The Comfort Seat and Wheel Module (CSWM) directly provides power to the seat heating elements in the seat cushions and backs for seat heating. Fused ignition (run) circuits are used, so that the heated seat system will only operate when the ignition switch is in the On position and the engine is running. The module responds to heated seat thermistor sensor feedback from each heating element and ignition switch status inputs by controlling the electrical output to the front seat heating elements. The heated seat system will turn off automatically whenever the ignition switch is turned to any position except Run.

Pressing a heated seat switch once will select high-level heating and pressing the same switch a second time will select low-level heating. Pressing the switch a third time will shut the heating elements off. When the switch is pressed, the CSWM energizes an integral solid-state relay, which supplies Pulse Width Modulated (PWM) current to the heating elements. If high-level heating is initially selected, the heated seat control system will automatically switch to a lower level temperature after 50 minutes of continuous operation at the desired temperature level. Operation in the low-level setting automatically turns to off after 45 minutes.

The driver seat heat system and passenger seat heat system each consist of a cushion element connected in parallel with a back element. Both systems have a seat cushion with a thermistor sensor that provides feedback to the CWSM. Both systems seat cushion and seat back have a thermostat that will request the heated seat to turn off if the temperature reaches or exceeds 54° C +/-9 (135 °F +/- 9). The CSWM will also turn off the heated seat elements if an open or short in the heating element circuit is detected.

Auto On Feature 

The Auto On feature is a customer configurable feature that when enabled will activate the driver heated seat and heated steering wheel on engine start based on ambient temperature. If Auto On feature is enabled, and the ambient temperature is at or below 4° C (40° F) the CSWM will activate the driver heated seat and heated steering wheel feature at the high level during engine start. This feature also works with Remote Start.