Good afternoon Forum,

I have a 2002 Buick LaSabre Custom with 48k miles on her. Yesterday an issue developed with the dashboard electrical system. First the chime sounded. Then all the warning lights on the dashboard all lit up like they do when first starting the car. The gages spike, and then most of the lights go off, but some will randomly stay on. It periodically repeats the same thing while driving around and different lights will stay on. The gas gage does not register the almost full tank of gas I currently have. The temperature gauge will sometimes register correctly and sometimes not. The transmission indicator doesn’t light up the gear. (I.e. P R N D 3 2 1).

Concurrently:
1. The power door locks don’t work
2. The electric trunk release doesn’t work
3. The radio has power when the vehicle starts but looses power shortly after.
4. No power to the 12v sockets in the ashtray area
5. The interior lights aren’t working


I took the vehicle to AutoZone this morning to have the battery and alternator tested and they both came back fully functional. O’Reilly’* ran a diagnostic on the car with no codes registering. I removed the panels under the steering wheel and made sure all the connectors are secure.

Any suggestion'* would be greatly appreciated? I’m at a loss as to what to repair.

You need to have a real shop scan it. Those places don't scan all the modules.

Has it been raining?

Is any of the carpet wet?

How long have you owned the car?

How many miles on the car?

I’ve owned the car for a little over a year, it was a friends mothers car that he inherited after she died. It sat idle for about 6 years once he got it. It has been functioning well once I got a new battery, did a complete break job, purchased new tires, replaced the fuel pump, changed all fluids, etc.

It has rained her, but other than the times I’m driving, Henrietta is parked in my garage. And there is no moisture inside the vehicle. This issue just started a couple of weeks ago and per much research, indication is a faulty BCM.

There are only 48k miles on her. When I got her in January of 2023, she only had 28k mikes on her.

I’ve purchased a used body control module on eBay but have yet to install it. So far she still drives, but I need to find someone to program the replacement BCM with the VIN, and true mileage, and whatever else needs resetting.

Any further recommendations are appreciated.

Why did you buy the BCM without any testing? You most likely wasted your money.. Don't waste more by having the used BCM programmed.
You never scanned the module that you need to get the codes from.
Looks like the suggestions you are looking for are what parts to shoot at the problem.
Good luck.

Call it a hunch: I'd drop the tank and check all wiring. Maybe try to figure out the gas gauge issue while you're there.

This platform isn't known for these types of issues with a dry interior. With so few miles on it, I wonder if something was damaged etc. during replacement of the fuel pump. The right wire with the wrong short could cause all kinds of mayhem.

I did have the vehicle scanned for error messages and none were found. I also had the battery and the alternator checked and they both came back with no issue. Everything I’m reading on line is indicating a bad BCM. It’* repeatedly resetting it self while driving, each time a different display of lights stay on until the next reset where a different set may stay on.

The dealership wants about $700 to reprogram the replacement BCM. Is there anyone else that I should contact to program the replacement BCM with my VIN number and current mileage?

The fuel pump was replaced when I got her in January 2023 because there was no gas circulation to the engine. It has been working ever since and the gauge has been functioning properly. The spiking of the fuel and temperature gauge and the continuous resetting of the system while driving is, per everything I’m finding on forums like these, of bad BCM. That all began about a week and a half or so ago, after hitting a pot hole on our lovely Dallas streets. I’ve done my best to check all connections, and looked at all the grounding connections.

I called the dealership yesterday to see how much it would cost for them to program the replacement and they quoted around $700 with no guarantees. Is there some other shop that I can have that done at that might be cheaper? Or is it something I can do myself with a VCX Nano or other module diagnostic/Programming system?

Most likely what you have is a problem with the power and or ground that feeds the BCM. More than 90% of BCM'* are replaced while perfectly fine. If you do not load test the power and ground circuits of ANY module before condemning that module you will more than likely replace a perfectly fine module.

Sorry, I have to ask: Did you see my post up there? ^^^^^^^

Dropping the tank and checking the wiring is way less expensive than replacing the BCM, and if something was pinched or cut or whatever during the fuel pump replacement then there could be a short etc. that is causing the BCM to have issues.