F-body BCM problems will cause you to pull your hair out when you’re trying to diagnose it. Your car will start then it won’t, the music will be on then the radio will shut off, lights might flash at you on the dash, or they might just not work at all…sometimes the windows and locks will work sometimes they won’t and because it is intermittent, you’ll start flipping fuses, changing relays and every time the problem goes away, you’ll **THINK** you fixed it only to have the problem come back again.
I’ve owned 3 F-bodies now and all 3 have had their BCM go out on me with different symptoms that caused me grief… My last episode of issues which you can see in this video below took me awhile to narrow down to being the BCM.
Well if you are having the issues I mentioned above or seen in the video (you may only have some of these issues), that’s your BCM which is also known as your Body Control Module and it can be expensive to replace from the dealer.
Lucky for you, you may not need to spend the money on buying a new BCM and you may be able to repair it yourself / have an electronics shop repair it for you for next to nothing.
First thing is first… locate your BCM module and remove it from your vehicle. On All F-bodies, it is located on the passenger side behind your airbag. You’ll need to get it from the bottom, so you’ll need to remove the plastic plate under your glove box as well as the glove box itself in order to access the BCM.
You will see a box that looks like this:
Unhook the wiring and pull it out of the car and take it to a clean workbench / space. Here you can open it up.
Do not touch any of the circuitry and make sure before you grab the board with your hands on the edges, you ground yourself out by touching a piece of metal (this eliminates you accidently shocking the board with your fingers and possibly damaging it further)
If you fold the box down like this, the board will pull out nice and easy.
Now you have the circuit board out, turn it around. What you will see will be thousands of little solder joints as like the below photo- you want to locate where I have highlighted – the 5 solder joints in the shape of a “T”. I enlarged the picture so you can easily note where the solder joints are.
These are the solder joints that are giving you problems. If you know how to solder, take your soldering gun, flux and some new solder…heat up all 5 joints and retouch them up with solder. These 5 joints are a known GM failure. This will fix your BCM problem 9/10 and will save you $500 from buying a new BCM through the dealer.
Close everything back up, and reinstall it in your vehicle after you have re-soldered these joints.
If this hasn’t fixed your problem you will need a new BCM. A new BCM from the factory will not require a new key to be cut, however, if you pick up a used BCM you will need a new key cut with the appropriate resistor from the vehicle it came out of put in, or you will need to perform a VATS (vehicle anti-theft system) bypass.
This website has a great write-up already for how to bypass VATS at your ignition that you can follow!
If you click on the two “Bypass” diagrams you’ll have all the information you need to complete the bypass.
Make sure you share this with any of your fellow F-body owners who are pulling their hair out diagnosing BCM issues!