Thread: Will Different BCM Cause Keyless Entry to not Work?

Hey all,

Sorry if this isn't in the right spot but my question is in regards to being able to use a different BCM and still use the same key fob without any reprogramming. I've been chasing a wiring issue in my interior light circuit and have come to the conclusion that there is a short in my BCM which keeps causing my interior lights to not work so I will be replacing it. However, it just dawned on me that since the BCM is pretty much the brain of the car that it might control the unlocking and locking of the doors via the key fob too. Anyone know if replacing the BCM will mean no more keyless entry?

I can only speak with certainty about my BCM type.

Type 4. Part No. 739803

I swapped out my BCM with a used JY unit and my remote lock/unlock/trunk still worked. There was no re-learn or programming required.

Ok. I guess I'll find out for sure when I actually swap but just thought I'd ask. Thanks!

No problem! Do you already have one sourced, or are you needing one?

Still needing one. Got a pic of the one from my car with all the numbers and such so I can compare to see what will work.

Okay. I ask because I have one sitting here doing nothing...

Does it work and would you be willing to ship?

Sure! But before you buy a BCM, I have to ask... What kind of problem are you having?

I bought this because I'm chasing down a lighting issue also. I determined it wasn't the BCM's fault when I put this one in. (Car did the same thing). I would be able to test all functions of this BCM in my car EXCEPT the 25 second theater dim function. My courtesy lights stay on til the 10 minute battery save function kicks them off. I guess I could still verify that that works using a DVOM on the output wire.

If you still want it we would have to figure out how much it's worth. I just checked, and it fit's in a USPS small flat rate box. So, whatever that costs...

None of my interior lights work and I keep blowing fuses. I thought that it was just a wire that shorted or something but wasn't 100% sure. I was using a GM sevice manual that showed how to test the BCM and after testing everything how it told me to it said that the BCM was bad and needed replacement. It never states why it needed replacement so I was still thinking that out of all the wires in the car, one of them could still be the issue. I finally got some free time to check the circuit using a bulb that was plugged into where the interior light fuse was. I read somewhere that if you do that you can start pulling out bulbs 1 by 1 from the interior and when the light goes out where the fuse is then you know that's where your problem wire is located. So needless to say I had every single bulb out and the light was still on. I decided that if I unplugged the BCM and if the light would shut off then there is a short within the BCM. If the bulb would stay on then the short is a wire from the fuse block to the BCM. After I unplugged the BCM the light in fact when out. That is how I came to the conclusion. I also remembered the test I ran before and figured that test found a short and that's why it said it needed replacement.

I'll pm you on your BCM

Got another BCM today plugged it in and blew another fuse.... back to troubleshooting.

Did the BCM have any trouble codes?

I'll have to check sometime when I get a chance to look at it some more.