Leej

I just purchased an 2004 E320 with 170K miles, and it has some issues...

First, Brake warning light is on, and SDS says SBC pressure reservoir was bad. I'm assuming dealership will replace SBC under warranty; I will make appointment next week.

Second, I am also getting the battery with visit workshop warning. SDS says that the Component N85 (Battery control mudule (BCM) is defective. However, SDS also says the Rear SAM also has a fault. Is it possible that the Rear SAM is causing the BCM problems, or could the defective BCM be causing the Rear SAM problem??? I think I could replace the BCM from one on ebay for about $80 (I assume the Dealer would be MUCH more), but I would probably let the Dealer do the SAM. I'm sure SDS could help me further diagnose, but I haven't gotten deeper into it yet, and I'm a noob with SDS...

I'm also getting passenger and driver side SAM faults... Previous owner replaced the Aux battery about 2 months ago, is it possible that all of these SAM and BCM problems are related???

Any advice or suggestions would be appreciated.

THANKS

Lee

scotterikson

I just had SBC replaced in my 04 E320 4matic under warranty. Planned on paying a diagnostic fee (or something), and was pleasantly surprised that my cost was $0.
What are the faults in the SAMs? Faults don't necessarily indicate a bad SAM, more likely a component powered by SAM
I'd go ahead and replace the BCM, erase faults, and do another quick scan with the SDS

Leej

Are there any special procedures for replacing the BCM, or just disconnect and reconnect the replacement?

konigstiger

See attachment.

mersum1es

Rear SAM neeed to be coded right, alternator (actually voltage regulator) must be right type, there is also newer type of BCM available which need software update in order to work properly.

Leej

FIXED, replaced BCM

Ordered used BCM (A 211 540 27 45) on ebay ($100), swapped out per procedures above and "Battery Visit Workshop" light is gone. Very easy replacement, took less than 15 minutes.