Slow draw on battery
 

Hi everyone

First time caller, long time listener. This might get kinda long.

I have a 2000 LS1 2.2L with 71k miles. I haven't had any major issues until recently. I'm the 2nd owner and have owned it close to 9 years. On a couple of the cold days it acted like a dead battery when I tried to start it. My jumper box said it had 11.7v. Started right up with the box on it.

Seemed ok for a month or so. But then did the same thing (was much warmer by then). Couple days later, most of the dash and door locks wont work and it's stuck in park. So... BCM

Have been told in the past BCM=dealership only. $1k later... (yeah I know) it's ok for a couple days. Then starts acting like a dead battery again. Same 11.7v reading but fires right up with the box on it.

Didn't trust it enough to drive it so I did some research. Decided to take it to MY mechanic. But when I went to jump it, it was down to 7.1v now. My guy says seems like it's still a BCM issue and take it back.

I don't completely trust dealerships. $450 for the module, $430 in labor, a 40 mile test drive(!!!) and they kept calling it a Vue haha. Really not looking forward to taking it back.

Any ideas?

Also, I read and was told by the dealership, that if it's stuck in park to just turn the key to on and step on the brake to shift to neutral but that didn't work. What to try next?

Thanks

The step on brake part is to release the Brake Transmission Shift Interlock (BTSI) which requires you to hold the brake pedal down in order to shift gears. It is an electrically operated solenoid to the best of my knowledge that physically prevents shifter movement.

Turning the key and stepping on the brake is fine when your battery is fully charged; you should hear a faint or not so faint click near the shifter, and you should be able to shift it out of Park. If there is not enough juice in your battery to operate that solenoid, you won't be shifting period OR your BTSI system or solenoid has an issue.

BCMs are routinely pulled and used from junkyards -- but must be reprogrammed by someone with a GM tech II device and the correct software. Usually ends up being the dealer but at least you save on parts. Complication is making sure you get a used one that is compatible w your vehicle. And you don't know if you're getting a problem child until after you pay to have it reprogrammed. $430 in labor?? Were they using a Fisher Price tool set?


Have you had the entire charging system load tested?
Autozone and similar will do it for free.
Possible battery or alternator diode issue.

Go get another battery. Take that one with you and have it load tested. I'll bet it has a dead cell in it. 11.7 volts is NOT enough to start your car. You need a good 12.45 volts in your battery. Don't let the dealership touch your car. You'll be paying for the cost of a good used one by the time they're done throwing parts at it.