03-14-2012, 08:07 PM
Date registered: Mar 2010
Vehicle: '04 E55
Is it possible to bypass battery control module?
I have a W211 E55 with extensive aftermarket accessories for the audio/visual system. The car was a show car and since I've owned it the convenience features have been disabled and it starts beeping intermittently. When running diagnostics multiple battery control modules errors are triggered. I've replaced the trunk battery, accessory battery, accessory battery relay, and battery control module. After doing all that I've also reprogrammed and updated the firmware for the BCM. Still having the same problem. The system has full voltage but the BCM still thinks it does not. Is there some way to bypass the BCM or "trick" the car into not checking voltage?
Thanks in advance for any advice.