Individually controlled driver and passenger side electrically heated front seats were available as a factory installed option when also equipped with the power seat option. The heated seat system allows both the driver and the front seat passenger the option to select one of two seat heating ranges, Low or High, or to turn the individual seat heaters Off using the heated seat switches located in the center lower bezel near the bottom of the instrument panel center stack.

The heated seat switch circuit operates on ignition switched battery current supplied through a fuse in the junction block, only when the ignition switch is in the On position.

The heated seat system consists of the following components :

• Heated seat elements
• Heated seat sensors
• Heated seat module (or memory heated seat module)
• Heated seat switches

Heated seat switches

The heated seat switches are mounted in the instrument panel center lower bezel, which is located near the bottom of the instrument panel center stack. The two three-position rocker-type switches, one switch for each front seat, provide a resistor multiplexed signal to the Body Control Module (BCM) through separate hard wired circuits.

Each switch has an Off, Low, and High position so that both the driver and the front seat passenger can select a preferred seat heating mode. Each switch has two Light-Emitting Diodes (LED), one each for the Low position and the High position, which light to indicate that the heater for the seat that the switch controls is turned on. Each switch is also back lit by a replaceable incandescent bulb.

The heated seat switches and their LEDs cannot be repaired. If either switch or LED is faulty or damaged, the entire switch unit must be replaced. The incandescent switch illumination bulb and bulb holder units are available for service replacement.

The heated seat system also relies upon resources shared with other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus network. The PCI data bus network allows the sharing of sensor information. This helps to reduce wire harness complexity, internal controller hardware, and component sensor current loads.

Heated seat operation

There are three positions that can be selected with each of the heated seat switches: Off, Low, or High. When the top of the switch rocker is fully depressed, the High position is selected and the high position LED indicator illuminates. When the bottom of the switch rocker is fully depressed, the Low position is selected and the low position LED indicator illuminates. When the switch rocker is moved to its neutral position, Off is selected and both LED indicators are extinguished.

Both switches provide separate resistor multiplexed hard wire inputs to the BCM to indicate the selected switch position. The BCM monitors the switch inputs and sends heated seat switch status messages to the Heated Seat Module (HSM) or the Memory Heated Seat Module (MHSM) over the Programmable Communications Interface (PCI) data bus. The HSM or MHSM responds to the heated seat switch status messages by controlling the output to the seat heater elements of the selected seat. The Low heat position set point is about 97° F (36° C), and the High heat position set point is about 105° F (41° C).