Pinpoint Test B : The Left Heated Rear Seat Is Inoperative: Notes

WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Refer to Climate Controlled Seats for schematic and connector information.

Normal Operation and Fault Conditions

When the LH heated rear seat control switch is activated with the ignition ON, a ground signal is supplied to the heated seat module from the switch. When commanded ON, voltage is supplied to the heated seat switch from the heated seat module to illuminate the switch indicator. The heated seat module also supplies voltage to the LH rear seat cushion and backrest heater mats, which are connected in series. Temperature is maintained by the heated seat module using a sensor contained within the cushion heater mat. The heated seat module supplies a reference voltage to the temperature sensor and monitors the return signal from the temperature sensor for controlling current flow to the heater mats. The heated seat module remains ON, heating the seat and maintaining temperature until switched OFF or the ignition voltage is switched OFF.

Possible Sources

Wiring, terminals or connectors
Heater mat
Heated seat switch
Heated seat module