This BAS/ESP is driving mad, I have read just about every thread here and on the benz forums regarding this issue. At first it was intermittent and the reset procedure would fix it then it was constant and reset would not clear it. No codes were present, had the brake fluid changed and the light went out for a few days. Then it came back with 2 codes.

c1010 CAB system under voltage
c1200 brake lamp switch circuit

Changed the battery and brake lamp switch even though I was not having any of the other problems associated with them. No change light is still on, had the shop clear the codes drove it for a while then took it back to check for codes. Seven codes now.

c1010 CAB system under voltage or according to some lists battery system low
c1100 left front wheel speed sensor
c1140 steering angle sensor
c 1529 undocumented (on their scanner)
c1202 release switch plausible
c1025 can signal
c1332 bas solenoid valve circuit

At least some of the codes now point to known fixes but damn, what a pain.
Alternator tests good by the way.

 

Well it does point to a wheel speed sensor.. can you clear the codes and see what pops back up.. I just wonder how many of those codes could tie back to a single "real" issue.. as in under voltage is a result of the speed sensor also..

 

Yeah, a single real issue would be nice. I did have them clear the codes, I will bring it back and see what codes return.

 

Instead of driving around a while.. I'd see about clearing them.. turn car off.. restart.. and see if anything pops up before giving it a chance to compile errors ?

 

OK, I give up, at least for now. Took it back in to check for codes and nothing, no codes at all.
I'm just going to cover the light with electrical tape and revisit this issue in June when I have more time.