Heated Seat System

Individually controlled electrically heated front seats are available as an factory-installed option on this model. Vehicles with this option can be visually identified by the heated seat switch mounted in the center console. The heated seat system allows the front seat driver and passenger to select from six different levels of supplemental seat heating, or no seat heating to suit their individual comfort requirements. The heated seat system for this vehicle includes the following major components, which are explained in detail later:
- Heated Seat Switch - One heated seat switch is used per vehicle. The switch is mounted in the center console, behind the gear selector and has two rotary knobs, one for the driver and one for the passenger front seats. Each rotary knob has six different detents (0-6), to indicate the desired level of seat heating. Zero(0) being off and 6 for the highest level of seat heating. There are three Light Emitting Diodes (LED's) in the heated seat switch. The first LED illuminates the heated seat symbol on the switch anytime the ignition switch is in the ON position. The remaining two LED's illuminate the selected numbers on the switch, indicating that the heated seat system is on and the level of seat heating selected.
- Heated Seat Module - Two heated seat modules are used per vehicle, these modules contain the solid state electronic control and diagnostic logic circuitry for the entire heated seat system. Each heated seat module is mounted under each of the front seat cushions.
- Heated Seat Elements - Four heated seat elements are used per vehicle, one in each front seat cushion and one in each front seat back. These elements, which are integral to the individual front seat cushion and front seat back trim covers are connected in series with the heated seat module.
- Heated Seat Sensor - Two heated seat sensors are used per vehicle, one for each front seat. The heated seat sensors are integrated into each of the seat cushion heating elements. The temperature sensor is a negative temperature coefficient thermistor.
- Low Voltage Cut-Out Relay - The (12V) power to the heated seat elements are supplied through a relay that removes power from the heating elements when a low battery voltage is sensed by the power-train control module (PCM). This micro-relay is located in cavity #8 in the Power Distribution Center (PDC).

Following are general descriptions of the major components in the heated seat system. See the owner's manual in the vehicle glove box for more information on the features, use and operation of the heated seat system. Refer to Wiring Diagrams for the location of complete heated seat system wiring diagrams.

The heated seat module receives fused battery current through the low voltage cut-out relay in the Power Distribution Center (PDC). This relay is controlled by the Body Control Module (BCM) only when the ignition switch is in the run position. The heated seat switches receive battery current through a fused ignition switch output (run) circuit also when the ignition switch is in the Run position. The heated seat module shares a common ground circuit with each of the heated seat elements. The heated seat elements will only operate when the surface temperature of the seat cushion cover at the heated seat sensors is below the designed temperature set points of the system and the system voltage is above the cut-out level.

The heated seat module will automatically turn off the heated seat elements if it detects a short in the heated seat element circuit or a heated seat sensor value that is out of range. The heated seat system will remain ON anytime the ignition switch is turned to the ON position and the heated seat switch is at any of the #1 through #6 positions.

The heated seat module monitors inputs from the heated seat sensors and the heated seat switches. In response to these inputs the heated seat module uses its internal programming to control outputs to the heated seat elements in both front seats and to control the heated seat LED indicator lamps located in both of the heated seat switches.