GM III body control module
 

Been having probs with electrics on my e39 M5 (RHD UK spec 2000)- Remote locking and internal c/locking stopped working (although still works off drivers door lock??), courtesy lighting and internal alarm sensors also packed up. Car still starts and everything else is fine. Have tried the remote resetting and that didn`t help either. This all occurred after new battery fitted. From what I've read here and elsewhere, it seems the GM3 module may have been damaged. Problem is mine is part no. 6135-6 922 272 and has `HIGH` inscribed on it. All the ones advertised on ebay have different numbers and `LOW` which makes me think that maybe they aren`t suitable for the M5-
Does anyone have any suggestions before I spend my hard-earned pounds?
After all, there is a recession on...something to do with sub-prime lending...we have no idea what that means by the way..Cheers

Sub Prime means loans to people who can't pay it back....basically. Sounds like you may have a bad ground somewhere. It's possible the new battery install may have sparked and killed a transistor inside the brain box, but more than likely it's just lost it's memory. Do you/can you hook it up to a scan tool? Look for codes, or no communication, probably worth you while to take it to a beemer shop and have them diagnose it before you spend big bucks.

Thanks, I may have to try that-I don't have the facility myself. Just bought used module off ebay to try first...different serial numbers but according to realoem.com it should be compatible.........we will see....??

yep-problem solved. Just fitted a used module off a scrap 523 and bingo...everything working fine. i guess the battery change (or the attempted jump-start) maust have frazzled something. Anyway that was just 15 sterling pounds...god only knows what a BMW dealer would charge!

Uber bucks is what they would've charged to fix it. You didn't mention the jump start. Jumping can be DANGEROUS for computers the best way to do it is at the factory supplied port in the engine bay with one of those jump boxes. Using another vehicle can (as you found out) cook computers in both vehicles actually (ain't progress grand?). Congrats on the cheap fix though, nice work.