Heated seat stuck on?

[Kiph]

I recently purchased my '15 legacy and love it. The only issue is my driver seat is stuck heating. I can toggle through all 3 heat modes but it doesn't make a difference. Even when the switch is off it still toasts my buns. Is there a fix for this or is it a known issue?

[KSKarl]

You say you toggle the switch through all heat levels. When you do that, do the switch lights follow your toggle? That would mean the switch is working and the controller itself has failed. Not sure if that's included in the body computer, or a separate piece.

[Kiph]

When you do that, do the switch lights follow your toggle?

 

Correct, everything seems fine with the switch but it doesn't adjust the temperature as far as I can tell. Do you lnow if there is a fuse to the heated part of the seat specifically that I can pull? I was also thinking it might be a relay stuck open, but wouldn't the switch still toggle modes in that case? Thanks for the input.

[ammcinnis]

See the attached wiring diagram from the 2015 FSM.

 

The seat heater relay is energized whenever the ignition switch is in ACC or RUN position, so that's not the problem. The front seat heaters are directly controlled by the A/C Control Module, using switched-ground circuits. Power to the driver's seat heating element(s) flows through pins 1 and 2 of connector i181 (at the A/C CM).

 

It seems the failure could be in the A/C CM, or it could simply be be a pinched (i.e. grounded) wire somewhere between the seat and the A/C CM. The first place to look would be under the driver's seat. That area beneath the seat would be highly suspect if the seat frame has been replaced or if the seat has been removed for some other reason.

 

Unfortunately, with a used vehicle you never know what the previous owner(s) may have done to it.

2015_Legacy_Outback_FSM_WI-413_Seat_Heater.pdf

Edited August 28, 2019 by ammcinnis