SL55/63/65/R230 AMG: Power Control Module questions
Thread Starter
Senior Member
Joined: Mar 2021
Posts: 271
Likes: 21
From: Rocky Mountains, Colorado
Just sold my '11 Porsche TurboS cab for an '03 SL55!
Power Control Module questions
Still sorting through various issues on my recently acquired '03 SL55. I've been fooling with the 'Consumers Offline Message' for awhile and am close to buying a new Vehicle Power Control Module (eeek $600+). But am trying to gain confidence before making a bad decision. This module is variously called the Battery Control Module and Energy Control Module etc. and is located in the trunk near the back of the right wheel well. I see there are one or more p/n upgrades and no used parts out there so it seems to be a chronic failure point??
My STAR DAS gives me code B1832 "faulty starter battery". Both batteries are new, the Starter Battery is MB OE, and the Systems battery is a premium Gel from Napa. They both have near full charge as judged by putting my smart trickle charger (normally on the systems battery) on either; it quickly turns OFF indicating full voltage of 13.9-14.1V or so. I also had the Starter Battery checked at the local tire shop (not a full load test like I've seen before) his hand held tool indicated 773 CCA and no bad cells. If I use a VOM I get about 13.5V on a cold car that's sat overnight.
Other symptoms: It will barely (sometimes not at all) recover the consumers after a 10 mile drive, or two 10 mile legs. Recently it wouldn't unlock the doors with the fob, sometimes the trunk won't open with the key fob, and lately after clearing the battery fault code, I started have trouble starting it - I'd get a red dash message "release brake pressure and the start" or something similar. Fiddling around with the key seems to overcome the problem......but its pretty erratic.
Also after such an event, and 10+/- miles, I checked STAR again, no fault listed for this module (possibly not soon enough to re record it as I'd cleared it 20 mi before and 4 ignition cycles) but with the ignition on, engine off, STAR showed 8.9V!!!
Alternator seems ok as with engine on, I'm getting 14+/- volts.
Any ideas? Help appreciated.
My STAR DAS gives me code B1832 "faulty starter battery". Both batteries are new, the Starter Battery is MB OE, and the Systems battery is a premium Gel from Napa. They both have near full charge as judged by putting my smart trickle charger (normally on the systems battery) on either; it quickly turns OFF indicating full voltage of 13.9-14.1V or so. I also had the Starter Battery checked at the local tire shop (not a full load test like I've seen before) his hand held tool indicated 773 CCA and no bad cells. If I use a VOM I get about 13.5V on a cold car that's sat overnight.
Other symptoms: It will barely (sometimes not at all) recover the consumers after a 10 mile drive, or two 10 mile legs. Recently it wouldn't unlock the doors with the fob, sometimes the trunk won't open with the key fob, and lately after clearing the battery fault code, I started have trouble starting it - I'd get a red dash message "release brake pressure and the start" or something similar. Fiddling around with the key seems to overcome the problem......but its pretty erratic.
Also after such an event, and 10+/- miles, I checked STAR again, no fault listed for this module (possibly not soon enough to re record it as I'd cleared it 20 mi before and 4 ignition cycles) but with the ignition on, engine off, STAR showed 8.9V!!!
Alternator seems ok as with engine on, I'm getting 14+/- volts.
Any ideas? Help appreciated.
Thread Starter
Senior Member
Joined: Mar 2021
Posts: 271
Likes: 21
From: Rocky Mountains, Colorado
Just sold my '11 Porsche TurboS cab for an '03 SL55!
Yes, I'm new to STAR DAS, and my Xentity isn't yet up and running. Wondering if the latter is limiting my view of this matter?
