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GM Tech (Cam)
GM Tech (Cam), GMC Mechanic
Category: GM
Satisfied Customers: 29534
Experience:  GM Grand Master Technician 2007. 14 years experience.
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2004 GMC: heated seats..The Drivers side heat keeps shutting off

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Hi, I have a 2004 GMC Sierra with heated seats. The Driver's side heat keeps shutting "off" on its own. At first it will stay on for a minute or so, then shut off. Continuing to turn it "on", it will again shut "off" on its own but in much shorter times. This happens to the normal seat and back mode, as well as the back only mode. The passenger side works fine when operated by itself in either mode when the drivers side is "off". But whenever the driver's side is "on", then shuts "off", the passenger side will shut off as well. Can you help me figure this out??

Hello and welcome to Just, Super mechanic here. About your vehicle.



There has been a service bulletin for that type of concern. It involves a reprogramming of the driver seat module. The dealership (stealership) would have to do that, I hate to say.


Here is what it states.



Interior - Intermittent Seat Heater Operation

Bulletin No.: 05-08-50-008

Date: August 19, 2005


Intermittent Heated Seats Inoperative, DTC B3941 Set (Reprogram Driver Seat Module)


2003-2005 Cadillac Escalade, Escalade ESV, Escalade EXT
2003-2005 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2003-2005 GMC Sierra, Yukon, Yukon XL, Yukon Denali


All with Seat FRT, Individual (Non BKT) (RPO AN3)

2003-2005 HUMMER H2 with Seat, Front Bucket Deluxe (RPO AR9)


Some customers may comment that occasionally the seat heater will not operate when activated. If the ignition key is cycled OFF and back ON again, the heated seat will operate correctly. Also, on some LB7 diesel engine vehicles, the seat heater may turn itself off during the first 10 minutes of operation. This occurs only with the first activation for the day and works correctly with subsequent activations immediately after the event. These conditions are intermiffent and DTC B3941 may be set.


Technicians are to reprogram the driver seat module with an updated software calibration. This new service calibration was released with TIS satellite data update version 6.5 available June 13, 2005. As always, make sure your Tech 2(R) is updated with the latest software version.











Customer: replied 7 years ago.
Are you sure this will cure the problem, I've heard from self proclaimed experts that I need a new heating element? If you are sure, how much does this cost to reprogram?

That would be the first thing that I would do, (reprogram) and it normally pays about .7 hrs. (seven tenths) and they will get an average of $75 an hour.


There is a chance that the element is bad, but the programming is what the manufacturer has determined to be the fix

Customer: replied 7 years ago.
Ok, this is my first time using JustAnswer website. I also just went out to my truck and tried to turn the ignition on, then off again to see if it would work, it did not, the problem still exsist. I want to make sure you get paid, but I also want to check and make sure that the reprogramming will fix the problem. Can I check on Monday from my service dept if they can reprogram this, then get back to you. Again, I would like to make sure yoy get paid for you time, I just want to keep my question open in case the reprogramming does not work and I have to pay another $18.

That's fine. You can log back in on this post at any time. You just may get a reminder after a couple of days. Just want to make sure that it gets fixed. Also, the way to diagnos it would be with the Tech2 scan tool anyway. Since the seat back and the cusion heater are seperate, and there are problems with both, I would think that the programing it would do the trick. If not, the heater elements and labor are more expensive.



PartOEM PartPrice
Seat Heater
Driver Seat
Passenger Seat
Seat Heater
Seat Cushion
Front Driver SideB0.81.1Notes
Front Passenger SideB0.91.3Notes
Rear Driver SideB0.81.1Notes
Rear Passenger SideB0.81.1Notes
Seat Back
Front Driver SideB0.91.3Notes
Front Passenger SideB0.91.3Notes
Rear Driver SideB0.30.5Notes
Rear Passenger SideB0.30.5Notes
With Side Impact Air Bags, AddB0.30.4


Customer: replied 7 years ago.

Ok, thanks, XXXXX XXXXX log back in soon!



Customer: replied 7 years ago.

I have an appointment for my truck on Monday Oct. 26, 2009 for the reprogramming. If it works, I will accept your answer! Thanks again!



Yeah, that is a good starting point, also the least expensive.
Customer: replied 7 years ago.
Well, the reprogram did not work, any other suggestions?
No. In that case it would have to be checked
Customer: replied 7 years ago.
What do you mean by checked. The mechanic who did the programming said his next step would be to check the wiring. He said at $75 an hour, anywhere from 3 to 5 hours just to look plus materials.
Yes, there could be a wiring problem, or the heater element could be bad.
Customer: replied 7 years ago.
Relist: Answer quality.
Hello. You will need to test the drivers seat heater elements. They are common for failing. HERE are instructions and specs for the test.
Customer: replied 7 years ago.
ok, let me try that?
Sure, post your results.
Customer: replied 7 years ago.
I will, thanks!
Any updates?
Customer: replied 7 years ago.
I have not yet had a chance to test the circuits, but will be doing soon. I assure you I will be getting back to you with the results. I wonder though, I just recently noticed that when using the key fob to open the door. The trucks seat would return the the position of the programming i had per key fob 1 or 2. After a friend just used the truck and had the seat forward. When i unlocked the truck with the key fob, the seat did not return to the programmed position. I wonder if this is related?

No this is not related to the heated seats. I read all the responses and you have an element out. I would be VERY surprised if it is not.

As for your assurance that you will come back, it has been my experience that 90% of the customers that say that, don't come back. You can reply and I WILL answer you after you accept.

Customer: replied 7 years ago.

Well I'm surprised because I already paid into this website, what good would it do me to not accept. I will try to test the circuits you told me. When I get the readings, if they are not in the parameters, then you are right and I will accept. If they are within the parameters I will let you know as well, so I can try whatevers next.

I sent this question in a few weeks ago and already brought it to a dealership and had them reprogram the seat module per the last mechanics instructions, that cost me $75. I told the mechanic that, and he did not have any further help for me. I definately will pay when I get help with a correct diagnosis. If you were me, Im sure you would do the same. Think about it. I could get any answer from someone on this website, which is new to me. Once I accept and the problem still exist, where does that get me. So please be assured that I will accept your answer if you help me find the problem!!!


Thanks, Tom

I am sorry if I upset you, I am pointing out the facts that I see. The Internet is not a safe place and I have been burned more times than I can count with promises of returning to pay, and I have no idea who you are, no offence.
Customer: replied 7 years ago.
Ok, I just bought a multimeter, and I also took off the leather seat cover, which had a slight rip, getting that fixed. Anyways I am able to access the connector you say. With the meter on the lowest setting, the value does not change at all. I actually can see the heating element and its connector. can I just test it there? What should that value be?
The specs for the elements are 1.5-.5 ohms.
Customer: replied 7 years ago.
So i can check just the element itself?
Yes, at the conenctor under the seat you can measure both elements.
Customer: replied 7 years ago.
going to do it right now, be back in a couple of minutes
Customer: replied 7 years ago.
ok, i measured from the gray connector and get no reading at all! however i measured the seat element itself and got 3.9 ohms

Ok, there are 6 terminals in that connector. Test the end ones.

Also 3.9 is good, but that is only the seat base, what about the back?

Customer: replied 7 years ago.
yes, i tried to test the end ones like you stated for the seat element, then i even tested the opposite end for the back element, both times i got a zero reading. I then even tested the two in the middle for the heck of it, and again a zero reading. I only then tested the seat element, only to see if i could get a reading, and then thats when i got the 3.9. Should i have the vehicle "on" and the retest?

No, truck off. Have you traced the wires to make sure you are on the correct connector? Are you testing the correct side of the connector? The side with the female connectors?

Customer: replied 7 years ago.
I am testing the side with the 6 pins sticking out, let me go check the other
Customer: replied 7 years ago.
ok, i checked the "right " connector this time! ok, the seat reading is again 3.9 and the back is 5.8
The back is out if spec. Replace it. It does not seem like much, but that is more than enough to shut it down.
Customer: replied 7 years ago.
Are you certain this will do it? I can order a back and replace it, I just want to make sure?
If it was my truck that is exactly what I would do. The module monitors the elements VERY closely. If it is even the slightest bit out, and 0.3 ohms is more that a bit, then it disables the system when that side is activated.
Customer: replied 7 years ago.
can i bypass the top or jump it to see if the bottom stays on
No, if you jump it you will lower the resistance and the only way to bypass it is to put a resistor in there of between 1.5-5.5 ohms. You need to replace that seat back element. If you want, take the back cover off. I suspect you will find a small burnt spot.
Customer: replied 7 years ago.
Ok, i will take the cover off, if i find a small burn sport, i will accept your answer even before i get the new element. if there is no burn spot, i will replace that element and get back to you. looking now online for an element! thanks for helping me find this!
No problem. The elements are about 150 or so. try for GM parts at dealer cost.
Customer: replied 7 years ago.
thanks, XXXXX XXXXX i was just looking!

Great minds think alike!

GM Tech (Cam), GMC Mechanic
Category: GM
Satisfied Customers: 29534
Experience: GM Grand Master Technician 2007. 14 years experience.
GM Tech (Cam) and 2 other GM Specialists are ready to help you
Any luck finding the element?
Customer: replied 7 years ago.

Well I just got done installing the new element here on Thanksgiving morning. Couldn't seem to find the time to do it any other day. You were right about the burn in the seat back element. It was about 1 to 2 inches in diameter, everything works fine now! Thanks for your help and patience with me!

I would like to use your services again in the near future with my heat/AC. As of now, I only get either out of the defrost mode. Someone told me its probably a relay under the dash. When I'm ready to tackle that I'll ask you so I can possibly get diagrams and what circuits to test, etc. How would I direct my question directly to you. Do you have an email that I could set up a time to log into Just Answer so you get the question first? Let me know! Thanks again and Happy Thanksgiving!

Tom [email protected]

All you need to do is in the first line of your Question state"For BlueGorilla only". If you use the link to do this below, it will also send me a message stating that you have asked for me.

Customer: replied 7 years ago.