Nor Cal SL55

I had a ABS/ESP malfunction last Sunday. It started when I went to pass a car and another car pulled out in front of me, so I downshifted into 2nd gear for extra engine braking. The engine speed went high (not anything harmful), but then the battery warning light came on in the instrument cluster. I pushed the system function button on the steering wheel and that cleared the battery warning light. About 10 miles up the road, I got on the freeway and the ABS/ESP malfunction light came on. Along with this, the transmission was locked in a certain gear and the engine speed was around 3500 RPM’s, at what I think was around 50 MPH as the speedometer also stopped working. I pulled off the freeway and into a Mercedes Benz dealer (there just happen to be one at the exit), but of course the service department was closed. Once parked, I could not restart the car as a warning light came on stating the car needed to be in park – which it was. The top was down and I couldn’t raise it either. The car’s voltage reading was right around 12v. I towed the car home.

I pulled codes with a Xentry/MB multiplexer diagnosis system that I have - see the attached "quick test" fault codes that came up.

I have never used this diagnosis system before, and am looking for a little help on the next step(s).

Both batteries are charged and trying an extra key did not help with getting the car to start.

Any help/suggestions would be great to hear.

Thank you,

Greg

desired_speeds

With both batteries charged, do a quick test and clear all the faults then do another quick test. When test is done, hit f8 and check the codes for each of the modules.

From what you've described, it sounds like your alternator might have fried.

Nor Cal SL55

Thank you for your help desired speeds!

I cleared the codes and performed a re-test. Attached are the values.

An electronic ignition switch appears to be the issue - Code B1016. The car has Keyless-Go. It could also be an alternator, as that was my first assumption as well. But first things first - the car won't start.

Other codes produced data that appears to be secondary and are a result of this issue. I would guess that the ESP/ABS and limp mode may be functions of this fault issue?.

Thank you for your help.

Nor Cal SL55

I have a new Electronic Selector module (whole shifter) on order from MB. This is a MB only product.

I will post the results once the part is installed and if I find other issues.

desired_speeds

if you hit F8 it will bring up more information regarding each current fault.

Nor Cal SL55

Yes - I did hit the F8 like you said. All other items appear to be related to the B1016 fault code. Once I get the new shifter in, I'll clear and do another quick test and see what I find.

For instance - the Lower Control Panel fault code was an air bag function warning (ESP system related as well?), The Tele-Aid fault code is because I don't have a subscription, etc.

You got me on the right track DS, thanks for helping me learn.

glhansenjr

and...?

cdk4219

That battery voltage is pretty low for a fully charged battery. Fully charged batteries are in the 12.7 range. I would charge the batteries or do a load test on them.

MK19

I'll be curious as well, but when I see all of those seemingly related Failures, I start think that the accessory battery in the trunk is bad. I'd load test that one and maybe save a bunch of time and money on the shifter module R&R. When that battery is bad, and voltage alone won't tell the whole story, all kinds of wackey module faults pop up. I chased a similar (but different) set of issues until another member here pointed that out to me.........in my case it was a fresh battery, but a bad one, and that really fooled me.