Demon possessed heated seats!

[swathdiver]

So I replaced the heat switch with an oem part and the heated seats still cycle on and off. I also hooked up the tech2 to the door module and I get no codes. Wtf

Did you try turning them on and off and if adjustable, doing that with the Tech-2?

 

[S33k3r]

So I replaced the heat switch with an oem part and the heated seats still cycle on and off. I also hooked up the tech2 to the door module and I get no codes. Wtf

What does the heat switch plug into?

 

[rgosart]

So I replaced the heat switch with an oem part and the heated seats still cycle on and off. I also hooked up the tech2 to the door module and I get no codes. Wtf

Thats because the problem is not the heated seat button, its either the window switch or the heating pad. Most likely the window switch or DDM.

 

[ivin74]

Did you try turning them on and off and if adjustable, doing that with the Tech-2?

I will try that today.

What does the heat switch plug into?

It plugs into the window switch

Thats because the problem is not the heated seat button, its either the window switch or the heating pad. Most likely the window switch or DDM.

My next option is to buy a new heating pad. If that does not fix the issue, I will buy a new window switch.

 

[smcnair]

It is the window switch that controls the windows and mirrors. Replace that part and all will be solved.

 

[ivin74]

It is the window switch that controls the windows and mirrors. Replace that part and all will be solved.

@smcnair
How sure are you that is the problem?

 

[rgosart]

@smcnair
How sure are you that is the problem?

If you disconnected the heating pad and the problem still exists I am about 99.9% sure. Even without trying that I am about 90% sure the window switch is the issue. It is very common.

 

[S33k3r]

What I have read elsewhere -- and no, I do not have a link -- is that the circuit board on the switch gets coated in dust from exposure to the elements. Then, when there is enough humidity in the air -- especially rain! -- the switch shorts. I've experienced this in a Silverado when it was 95+ degrees outside and a million percent humidity.

 

[ivin74]

If you disconnected the heating pad and the problem still exists I am about 99.9% sure. Even without trying that I am about 90% sure the window switch is the issue. It is very common.

I disconnected the heating element and it still does it.

What I have read elsewhere -- and no, I do not have a link -- is that the circuit board on the switch gets coated in dust from exposure to the elements. Then, when there is enough humidity in the air -- especially rain! -- the switch shorts. I've experienced this in a Silverado when it was 95+ degrees outside and a million percent humidity.

I'm going to bite the bullet and buy the window switch.

 

[S33k3r]

I disconnected the heating element and it still does it.




I'm going to bite the bullet and buy the window switch.

I have heard that if you simply clean it, you are good for another year or two. The sole caveat being that your switch isn't already in a constant state of flux. If this is intermittent, then the dirty circuit is likely your gremlin.

It is still a good idea to look into replacing the heating pads on the seat, since they are, at best, 14 years old (can't remember your model year, sorry).

 

[smcnair]

@smcnair
How sure are you that is the problem?

99.9%

 

[eliminatethebug]

Heated seats is my dream. But today, when I go on long trips, I have to use a portable heating pad, although it is small but very portable and convenient, who's freezing as I can read the Top article, here you will find a lot of information on how to keep warm.

 

[corvette744]

Im willing to bet its just one of the heating elements,you need to check the ohms on the wires.So raise your seat as hi as it will go,get an ohm meter and probe the connector- for the lower and upper at the connector.I would have someone sitting in the seat moving around-i had to do that when i found mine.Anything over 5 or 5.5 ohms its junk and needs replacing.Replacing the bottoms is easy the tops a little harder-and tops are more money.I cant stress the importance of pushing the seat or when someone is sitting in it to move around when testing-sometimes it wont show bad unless the burnt wires are touching.Thats how i fixed mine.I would not replace the heater element unless it shows high ohms-they are expensive to throw parts at it.Obviously test both seats upper and lower.

 

[S33k3r]

Found the link:

https://chevroletforum.com/forum/si...de-heated-seat-turns-itself-37318/#post241802

 

[Noggles]

If someone is having this problem (I can watch my heated seat lights turn on and off) should they start with the switch or the DDM? The heating elements work perfect so I am thinking I should start with the DDM. It sounds like the switch was redesigned so it wasn't as easy to turn on accidentally.

 

[milano]

Short answer: I replaced my DDM with ACDelco part and the issue went away.

Longer answer:

My seat issues started with the heated seat not staying on, driver side only. Passenger side had no problem.

Replaced heated seat element with Dorman 641-105 in September 2018 and confirmed that the original was visibly burnt and creating an open circuit.

If I remember correctly the new issue started not long after I put in the new element. As a temporary workaround, I unplugged the heated seat element from underneath the drivers seat and just ignored the clicking of the relay as the seat would try and turn on and then immediately turn off.

At this point the symptoms were the heated seat would continuously cycle through power on/off. What I mean by cycle through is that I would see the 3 lights all turn on indicating the lower seat was on, then it would go to 2, then 1, then off. Then it would turn back on again and go through the same 3,2,1, off.

It seemed to happen only when it was raining and would happen only occasionally if at all when it was dry. Also, if I just left the heated seat plugged after a while (10 minutes maybe) it would calm down and not have any issues. I recorded some of the behavior over a two-month period just to confirm.

I took out the DDM and the memory switch, opened them up and did not see any obvious issues with the parts or circuit boards and both were completely dry. I decided to start with the memory switch and replaced it with Dorman 901-196 in September 2019. No change, the issue persisted. I did not have time to continue so I just unplugged the element again.

For the DDM I purchased ACDelco 15883319, my original part was 15186208. Be sure to check your RPO codes to get the correct part. I installed it in November 2020 and the on/off power cycling has stopped.

To summarize, it seems like I replaced my bottom seat element and then had to replace the DDM.

Now some questions.

Does anyone experiencing this continuous power on/off still have their original bottom heat element? Or if replaced, did you replace with the original GM part instead of Dorman? I am wondering if the Dorman has a lower resistance than the OEM leading to the failure that is causing this issue.

 

[livingez_123]

And here I thought I was going crazy!

 

[ivin74]

I disconnected the heating element and it still does it.




I'm going to bite the bullet and buy the window switch.

Forgot to follow up, last fall I changed the window switch and the flashing lights disappeared. I did not even changed the heating element.