Test N: The Heated Seat Is Inoperative - Driver Or Passenger

PINPOINT TEST N: THE HEATED SEAT IS INOPERATIVE - DRIVER OR PASSENGER

N1:

N1-N2:

N2-N3:

N4-N5:

N6-N7:

N8:

Normal Operation
The driver and passenger heated seats share a common ignition and battery feed to the heated seat control switch assembly. The ignition feed circuit CBP18 (GY/OG) powers the logic board and illumination of the heated seat switch assembly and the battery feed circuit SBB28 (GN/RD) is used to provide voltage to the heater mats. The heated seat switch assembly uses shared ground GD145 (BK/BU) for the logic board and illumination.

When a heated seat switch is pressed with the ignition switch in RUN or START, a momentary ground is provided to the logic board of the heated seat switch assembly. The logic board then activates an internal relay in the heated seat switch assembly that provides voltage via circuit CHS02 (YE/BU) (driver seat) or CHS07 (GY/BU) (front passenger seat) to the bi-metallic thermostat that is part of the seat cushion heater mat.

The driver seat cushion and backrest heater mats are wired in series as are the passenger seat cushion and backrest heater mats. The heated seat system is designed to maintain the temperature by the opening (no voltage to the heated seat elements) and closing (voltage supplied to the heated seat elements) of the bi-metallic thermostat.

Possible Causes
An inoperative heated seat can be caused by:
- fuse(s).
- wiring, terminals or connectors.
- a faulty heated seat switch.
- a faulty heated seat relay.
- a faulty heated seat mat.