Principles of Operation

PRINCIPLES OF OPERATION

Front Power Seats
The driver and front passenger power seat motors are hardwired to the seat control switches on each respective front door trim panel. The circuits are normally at ground through the seat control switch. Each individual seat track or recliner motor circuit (if equipped) is switched to power when the specific adjustment position is selected.

Heated Seats

NOTE:
- If a passenger seat cushion heater element is faulty, a new occupant classification sensor (OCS) service kit must be installed and a new cushion heater element must be installed to the OCS service kit foam pad.
- When installing an OCS service kit equipped with heated seats, a new seat cushion heating element must be installed. Do not reuse the original equipment manufacture (OEM) OCS heated seat cushion element. The OCS service kit does not come with a heated cushion element.
- When installing a new driver seat heater element (cushion or backrest) or passenger seat backrest heater element, a new foam pad with the heater element already attached is required. A new heated seat element alone is not available for service for the driver seat.

Vehicles equipped with front heated seats have a heated seat module located underside of each front seat. The driver and passenger heated seat modules share a common battery voltage feed circuit and a common ignition voltage feed circuit. When the heated seat control switch is pressed with the ignition switch in RUN or START, a ground signal is sent to the heated seat module on either the high or low enable circuits to command the system ON or OFF in HI or LOW respectively. The heated seat module also will ground the respective HI or LOW indicator circuit at the heated seat switch providing a voltage path to indicate an ON state by illuminating the switch indicator. The heated seat module also supplies voltage to the cushion and backrest heater mats which are connected in parallel and operate together. Temperature is maintained by the heated seat module monitoring a temperature sensor contained within the cushion heater mat. The heated seat module supplies a reference voltage to the temperature sensor and monitors the return signal for adjusting the current flow to the heater mat circuits. The heated seat module is designed to remain ON, heating the seat and maintaining temperature until switched OFF or the time-out period occurs. If the ignition voltage source is removed, the heated seat module will enter an OFF state and will not return to ON until the switch is once again pressed with the ignition switch in RUN. The temperature sensor is not serviceable and must be replaced as part of the cushion heater mat or foam pad.