2003 hummer, H2. My heated seat turns on constantly when the weather warms up. I’ll turn it off and within three or four seconds. It turns itself back on. It works perfect except in the winter time when I turn on it turns itself right back off

I don’t really care to fix it at this point because it’s warming up outside.

I looked through my manual and couldn’t find any fuses or relays for the heated seats.

is there a fuse for the driver is heated seat or relay? I noticed a wiring harness with a green connector underneath the seat. If there is no fuse or relay can this harness be disconnected to stop the heated seat from coming on? Thank you.

 

Yes, you can unplug the green connector and the heated seat won't come on. That connector comes from the heater pad underneath the leather. To fix the heated seats coming on by themselves, I believe you have to replace the door module. I am having the same issue myself but have never bothered to fix it yet.

 

Fonzie I assume you're referring only to the driver's seat.

The DDM wires directly to the heater switches and communicates their settings to the "Driver Memory Seat Module" under the driver's seat, the DDM also sets the LED Indicators to show the current heater settings.

There's a DDM chip that reads the heaters switches and ones below all at the same time:-

• Left Front Door Ajar Switch
• Memory Switch 1
• Memory Switch 2
• Door Key Switch Signal

they're read as a bit "pattern" and then transmitted as a bit-stream, so it's unlikely this chip itself is faulty.

However DDM CPU PCBs is notorious for corrosion, you may get lucky and it'll be a case of gently brushing-off the corrosion/oxidization using IPA.
The area in yellow is most likely the best place to start, you can see some repaired tracks in the lower corners and at the top the chip.

It might be worth checking the above before committing to a new DDM, its easy to remove and disassemble and could save you some dollars....


If you search YT for "Hummer H2 drivers door module" I think there is some useful info✔️
[Awaiting Resolution]

 

Thank you so much. I will definitely take that apart and see if there is corrosion in there. I disconnected the harness the other day and that stopped the drivers seat from coming on which is great. It was way too hot outside to have a keep coming on. I’ll work on this in the next couple days and see if that will fix it. That would be wonderful and a cheap fix if it does. I really appreciate all the detailed information. The picture is worth 1000 words.

 

Fonzie Did you have any luck figuring this out? The same thing is happening to mine and you are right it is way too hot for heat seats right now.

 

U bet!!!! I never found a fuse for them. I reached underneath the seat, and I disconnected the wiring harness to the heated seat. It stopped it from coming on. If you need me to, I can take a picture of the harness tomorrow and post it. I am so very happy it’s not coming on anymore. It was to the point where is coming on every 10 seconds after I turned it off. It was strange for mine because in the winter time I would turn the heated seat on and it would click itself off, but in the warmer weather, it wants to stay on all the time.

 

That would be awesome if you could take a picture of which one to unplug I look under the front of my seat and I see 2. 1 with some larger wires that I am assuming would be the seat heat because of the amount of current flowing through them and then 1 to the right when you're looking at the front of the seat with smaller wires so if you could let me know which 1 to unplug that would be great

 

 

Sure of course. Here you go.

 

Sorry its an old post but I am having the same issue, do I have to remove the seat to access the green connector?