Heated Seats - Malfunctioning

blowin oil · May 24, 2011

I have 2005 GMC Yukon XL 2500 SLT. The heated seats are acting really screwy. This started about a week ago, over the last few days it has gotten worse. The heater is truning on and off by itself, and even switching between settings. I try to turn it off, but 30 seconds later its right back on again, full blast! This is extremely irritating, especially when its 80 degrees. I would guess this is a relay problem, can nayone point me in the right direction? Also, in the mean time, is there a way to disconnect the heat on the seat without disturbing the positioning adjustment?

Thanks!

blowin oil · May 25, 2011

Any thoughts at all?

&CDFiXER% · May 25, 2011

I am by no means a GM Tech, but have you checked the switches for sticking? Although, if it is both seats acting up then it is more likely the control module.

You should be able to disconnect the harnesses to each set of seat heaters, that way your seats remain functional otherwise.

JF1957 · May 25, 2011

Is it doing this on both front seats ?

blowin oil · May 26, 2011

Is it doing this on both front seats ?

It is only on the drivers seat. The switch seems to be working properly and the buttons have the same feel as the ones on the passenger side. I took the fuse for the heated seats out and that stopped the butt warmer, but the element on the back rest still gets hot. Guess I need to figure out which connection is for the back rest element. It's pretty tight in there, hope I dont have to take the seat out to do it.

Raleigh75 · May 27, 2011

Having the same problem on my 06 Sierra 1500 SLT. I bought an OEM replacement door panel switch, but that didn't help. I also took it to the dealership who "reprogrammed" the seat. That didn't work either. I'm leaning towards a bad ground or a short in some relay - I'm not leaving the dealership next time until it's fixed. It's 95F here in NC - too hot to have the seat heaters cycling on full-blast.

-Steve.

ChevyTech77 · May 27, 2011

Sounds like a driver's door or seat module issue. Could be a bad connection at either of those two modules also.

Raleigh75 · May 28, 2011

What's crazy is - if you leave the seat heater door panel switch unplugged, the seat heaters still cut on! So the door switch isn't the problem... it wreaks of a short somewhere.

blowin oil · June 6, 2011

What's crazy is - if you leave the seat heater door panel switch unplugged, the seat heaters still cut on! So the door switch isn't the problem... it wreaks of a short somewhere.

Let me know if you figure this out. I have unplugged my seat in the meantime until I find a solution. Thanks!

&CDFiXER% · June 6, 2011

The heaters could still turn on as the control box has electronics in it. There could be something wrong inside the control box causing the seat(s) to turn on regardless of any control switch. If the control box is like the 2009+ it has solid state outputs along with the controlling circuitry to 'talk' to the GMLAN. Solid state outputs can start to fail like this, but if it is both seats then I would vote that the problem is further 'upstream' of the output transistors, FET's, whatever and that upstream circuitry is triggering the outputs. If you have just one control module for both of the seats that are doing this, then you should try changing that module.

If you have one module for each seat then start looking for poor grounding or feed voltage. This seems a bit unlikely but is possible.

dansws6 · November 7, 2011

Does anyone figure this out yet?? I have a '06 Silverado Z71 and this issue has been driving me nuts recently. It seems to magnified during damp or rainy days. Please help...

saratoga · November 25, 2011

Same issue on a 2003 Tahoe. Intermittent on and off driver's seat heat. No issues with the passenger seat. After the driver's seat randomly turns on, I turn it off, but it comes back on, sometimes after 10 seconds, sometimes after 10 minutes.

There is a NHTSA bulletin #10006580 on this topic, but I haven't been able to find any info.

Can I just put in a relay to stop the power to the seat heat? Even if the switch on the door or the seat module turn on, the heat pads in the seat would not turn on unless the relay is switched on? If I actually wanted to turn the seat heat on I would have to press the regular button and also flip the switch on the relay? Would this work? Any idea on how to get a schematic?

gmtech4 · November 25, 2011

you guys are killin me .....

why wont you go get it looked at ,..it could be a bunch of things and being electrical ,you guys have no way to diagnose it yourselves ,,,,,,or fix it for that matter so WTF ??

it is most likely the elements but taking it to a garage and say "its the seat elements" you are shooting yourselves in the foot ,

no tech wants to see that on a work order and advisors are dumb enough to put in on the work order

sry....rant off

walterb · December 10, 2011

i had the same problem with my H2 Hummer. to keep from roasting [i live in Hawaii] i pulled the C/B.a couple of weeks later i needed to move the seat so i put th eC/B back in. the seat heat problem went away?