Thread: Getting a used BCM programmed at the dealer

So I've recently decided to do the heated seat upgrade in my 2007 GP base model. From the donor car which was the same year I grabbed the leather heated seats, climate control module and the BCM. I've finally got around to installing the seats and climate control module so all that is left is the BCM. I went to my local GM dealer today to find out how much it would cost to have the donor BCM programmed to my car to enable the heated seats and was told that a used BCM cannot have its VIN changed more then once so it cannot be put into my car. This goes against everything I've read online so I decided to call another dealer across the city. They told me something similar but the guy I spoke to said to call back monday to speak with someone that might know more. He also said I will likely need the donor VIN which I don't have. I plan on calling them back monday and maybe some other dealers but I figured I would clarify some things here in the mean time.

1) can a used same year, higher trim level donor BCM be reprogrammed for my car?
2) will I need the donor VIN?
3) would this new to me BCM cause any issues with other features? for example my car doesn't have the monsoon sound system but the donor did.
4) will the car be able to drive if I swap out the BCM before hand to save money?

Originally Posted by TheRiGuy

So I've recently decided to do the heated seat upgrade in my 2007 GP base model. From the donor car which was the same year I grabbed the leather heated seats, climate control module and the BCM. I've finally got around to installing the seats and climate control module so all that is left is the BCM. I went to my local GM dealer today to find out how much it would cost to have the donor BCM programmed to my car to enable the heated seats and was told that a used BCM cannot have its VIN changed more then once so it cannot be put into my car. This goes against everything I've read online so I decided to call another dealer across the city. They told me something similar but the guy I spoke to said to call back monday to speak with someone that might know more. He also said I will likely need the donor VIN which I don't have. I plan on calling them back monday and maybe some other dealers but I figured I would clarify some things here in the mean time.

1) can a used same year, higher trim level donor BCM be reprogrammed for my car?
2) will I need the donor VIN?
3) would this new to me BCM cause any issues with other features? for example my car doesn't have the monsoon sound system but the donor did.
4) will the car be able to drive if I swap out the BCM before hand to save money?

To answer your first question, I've been down that road and unfortunately you cannot reprogram them.

Not sure, but when I swapped my bcm with a donor vehicle, almost everything worked fine. I think there were a few features but the monsoon system isn't hooked into the bcm at all so that'll be fine.

Originally Posted by wstefan20

To answer your first question, I've been down that road and unfortunately you cannot reprogram them.

Not sure, but when I swapped my bcm with a donor vehicle, almost everything worked fine. I think there were a few features but the monsoon system isn't hooked into the bcm at all so that'll be fine.

how did you swap it if you cant reprogram it? can it just be swapped without any programing? or am i just miss understanding something?

can anyone please clarify what needs to be done with the BCM to enable the heated seats. Its cold up here in Canada lol.

Originally Posted by TheRiGuy

how did you swap it if you cant reprogram it? can it just be swapped without any programing? or am i just miss understanding something?

Sorry for the delayed response. In my experience, it "should" work just swapping without reprogramming as long as the accessories and options are similar enough. There might be a few things that don't work, but I really can't say for sure if it will or not.

Personally, I'd buy a used one and make sure they accept returns at no cost. Seeing how expensive they are new even on rockauto.com I'd go for it. I'm curious to see what happens, so please post the results!

Originally Posted by Bronco Boy

Real men prefer cold leather touching their arse.

lol I thought you did the swap and got the wiring sorted for the heated seats!

Originally Posted by Bronco Boy

Real men prefer cold leather touching their arse.

lol I guess I'm not a real man then because I solved that problem by swapping out the leather seat covers with my old cloth seat covers. Never liked the look or feel of leather seats.

Originally Posted by wstefan20

Sorry for the delayed response. In my experience, it "should" work just swapping without reprogramming as long as the accessories and options are similar enough. There might be a few things that don't work, but I really can't say for sure if it will or not.

Personally, I'd buy a used one and make sure they accept returns at no cost. Seeing how expensive they are new even on rockauto.com I'd go for it. I'm curious to see what happens, so please post the results!

Its dark and cold out right now so it'll have to wait until morning. I'll try putting in the one that I grabbed along with the seats it was the same year car and I'm not sure which features are controlled by the BCM so I don't know for sure if it'll match. I hope I don't have any security light issues which I would think I would with the VIN mismatch. Fingers crossed that it will work because I don't want to have to fork out $200+ to get a new BCM and that doesn't even include dealer programing just to have a warm ass in the winter.

Forgot to mention that depending on your skills with wiring, money, or time, there is a way to get these to work hi-lo with a toggle switch like the 97-03 seats. Actually, you basically take the seat harness from a 97-03 donor vehicle along with the switch and the thermistor (small resistor in your seat that regulates the temperature, there's already one there, but only the old one works).

I did this in a set of 05 heated seats that I swapped into my 02 gp and they are the best thing EVER!

Worst part other than the wiring is having to remove the seat cover and carefully dig out the old thermistor, and just getting these parts from the junkyard in general is a pain. I'm actually curious if you can't buy the parts new and make your own harness. The only thing that might be tricky is finding the part numbers, but I think it's just a basic relay system from the looks of it.

I can go into more detail, but most people aren't this motivated to get them to work. Doesn't cost much at all except time and frustration.

Originally Posted by wstefan20

Forgot to mention that depending on your skills with wiring, money, or time, there is a way to get these to work hi-lo with a toggle switch like the 97-03 seats. Actually, you basically take the seat harness from a 97-03 donor vehicle along with the switch and the thermistor (small resistor in your seat that regulates the temperature, there's already one there, but only the old one works).

I did this in a set of 05 heated seats that I swapped into my 02 gp and they are the best thing EVER!

Worst part other than the wiring is having to remove the seat cover and carefully dig out the old thermistor, and just getting these parts from the junkyard in general is a pain. I'm actually curious if you can't buy the parts new and make your own harness. The only thing that might be tricky is finding the part numbers, but I think it's just a basic relay system from the looks of it.

I can go into more detail, but most people aren't this motivated to get them to work. Doesn't cost much at all except time and frustration.

well I tried swapping my BCM with the used one as is and the good news is the heated seats work, they get nice and warm which is great! unfortunately I wont be able to listen to music since the radio says "locked" or go anywhere since the car wont turn over and says "staring disabled due to theft system" on the DIC. Fortunately everything went back to normal when I put my BCM back in and my arse got cold again

I am an electrician by trade so I'm sure I could figure out how to get the seat heaters working off a switch but I was hoping to get it going the intended way with the OEM buttons. I might inquire at the dealer if I were to find a new BCM cheapish if they could program it to my car with the heated seat function enabled but I don't think they can, they can only flash it with my VIN for it to work and my VIN will disable heated seats

Have you looked into aftermarket anti-theft bypass products? I don't have direct experience with your year, but I had good luck with late 90's GM VATS bypass. It's a cheap ($30) little chip/harness thing that sits in between the BCM and the ECU and tells the ECU that everything is fine with the BCM so go ahead and start and run. Perhaps there are similar things available for your year.

Sorry to hear! As far as the radio, I believe you can take it apart and de-solder a chip to get them to work if I remember correctly, but not sure about the no-start. I know for sure you can bypass that with a remote start device, but that probably wouldn't be cost effective. Not sure what other workaround there would be... I know rockauto.com has some decent prices though.

Originally Posted by sparkydog

Have you looked into aftermarket anti-theft bypass products? I don't have direct experience with your year, but I had good luck with late 90's GM VATS bypass. It's a cheap ($30) little chip/harness thing that sits in between the BCM and the ECU and tells the ECU that everything is fine with the BCM so go ahead and start and run. Perhaps there are similar things available for your year.

Thanks for the tip but I can't seem to find anything like that online for my car. If anyone knows if this thing exists for at 2007 GP please let me know.

Originally Posted by wstefan20

Sorry to hear! As far as the radio, I believe you can take it apart and de-solder a chip to get them to work if I remember correctly, but not sure about the no-start. I know for sure you can bypass that with a remote start device, but that probably wouldn't be cost effective. Not sure what other workaround there would be... I know rockauto.com has some decent prices though.

Interestingly I believe my radio already has the chip removed, its an "unlocked" six disc unit which did not come factory with my car. unless there's another way to unlock a OEM head unit that i'm not aware of and normally it works fine without having to be programed so its odd that it was still locked out with the new BCM. Only thing that makes sense to me is the fact the car I took the BCM from had the monsoon system but I think it was you that said that doesn't run through the BCM anyway.

As far as the aftermarket remote start idea, I actually already have a Compustar remote starter installed. I never actually thought to try starting it with that when the new BCM was in there, maybe I'll give that a shot at some point but I don't think that will help with the radio or anything else the BCM will be locking out even if the car does start.

Originally Posted by Scottydoggs

id try a security learn, might work on a bcm.

then if you can still get the radio out of the car you got the bcm. it should work. hoping you got it from a JY.

is there instructions somewhere on performing a security lean? I'm a little nervous on messing with anything security wise since I don't want to end up bricking my car and unable to fix it while simply trying to get a luxury feature to work. I did get the seats, BCM and climate control module from a JY cheap and did not take the radio which has been crushed along with the car at this point.

I went to another GM dealer today and discussed my options as far as what they could do and was told it isn't possible to get the heated seats working the intended way in my car. The BCM needs to be VIN matched to function and once the VIN in the BCM has been set it can not be changed so a used BCM is useless. This makes me wonder about all the used BCM's for sale online. They also said a new BCM wouldn't work because as soon as they enter the VIN of my car it will disable the heated seat function and just be a clone of the BCM I already have. So unless someone here has found a work around it looks like I'm SOL.

If no new solution comes up I might look into wiring up a hidden switch somewhere to manually control the heaters. It seems its as simple as putting a switch in place of the heated seat relay. I can only assume the system achieves its high/low heat function by controlling how long the elements are on with a thermistor. Hopefully It wont get to hot and burn out since there would be no form of high limit without the BCM control if I where to leave it on. I'd also have to check if the fuse has power at all times or only when the car is on because this could end up killing my battery if left on. I could also look into the older generation harness swap that was suggested.

Originally Posted by Scottydoggs

looks like your hard wiring in power to the switches and seats. its been done. one guy here added a aftermarket heated seat to the pass side. he picked up another stock switch, molded it to the other switch so it looks stock, and ran its power from that switch to the seat as per its harness.

he was also able to jump the lighting power from the stock to the new switch so it lit up as it should at night.

I did the same swap. The swap you're referencing kind of bypassed the relay so it only works on hot, and it could potentially burn out the heating element. The only way I found to correctly do the swap is to take the switch and harness from an older gp and use it in the new seat along with the thermistor.

Another option that I just thought about is that I actually created an arduino run program with full autotune pid controller software to heat various zones of a vacuum chamber I use at work. The hard part would be interfacing with the switches on the hvac. I know it would have to use gm's protocol and I should be able to splice into the data stream and find out the commands the buttons send and just trigger the arduino. Could just use manual switches too, or another interface. I could pretty much set the specific temperature the user wanted and hold it there. This might be a fun project!

Originally Posted by wstefan20

I did the same swap. The swap you're referencing kind of bypassed the relay so it only works on hot, and it could potentially burn out the heating element. The only way I found to correctly do the swap is to take the switch and harness from an older gp and use it in the new seat along with the thermistor.

Another option that I just thought about is that I actually created an arduino run program with full autotune pid controller software to heat various zones of a vacuum chamber I use at work. The hard part would be interfacing with the switches on the hvac. I know it would have to use gm's protocol and I should be able to splice into the data stream and find out the commands the buttons send and just trigger the arduino. Could just use manual switches too, or another interface. I could pretty much set the specific temperature the user wanted and hold it there. This might be a fun project!

I find it funny that it needs to be this difficult when in reality the only reason the heaters aren't working properly in my car right now is that fact that there is a 0 in a computer program that needs to be a 1 lol