Limp mode

[pjstarr63]

I have had an issue with the car going into limp mode. The repair shop has read the codes and they are all over the place. 28 codes on the last read. Mechanic does not know where to start looking. Thought it was the transmission ISM but no code indicating that. Codes cleared. Drove again and limp mode. 25 codes in reader. At a loss. I just don’t want to fix something and have the codes come back because it wasn’t the correct fix. Help!!

 

[Blobcat]

Hello and welcome

Fist thing I’d do is change the mechanic to one who knows Mercedes and preferably has Mercedes diagnostic equipment and knows how to use and interpret it.

 

[Wearsafoxhat]

As above. Using a good Mercedes independent will save you money in the long run, no guessing games with expensive parts..

Where are you, as the good people on here may be able to point you in the direction of one or two..


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[dry run]

Welcome Good advice so far!

 

[M80]

Has the battery voltage dipped before the 2nd test?

 

[mioba]

Where are you, as the good people on here may be able to point you in the direction of one or two..


Sent from my iPad using Tapatalk

Grange Moor I say....

 

[joderest]

I would delete all the fault codes and see what comes back.
It does sound like there was a battery low voltage issue which can trigger a lot of codes. Are they all live or stored ?

 

[pjstarr63]

I am in Kansas City. I have been going to this same Mercedes/ Bosch mechanic since 1999. He has worked on most of my old Mercedes. We did change the battery, test the alternator etc. Cleared codes both new and stored. Each time the faults that come back are in the 20’s. Nothing is consistent that would lead to a precise conclusion. Dealership might be next step.

 

[joderest]

I wonder if all the codes are linked to one module that has failed

 

[SL63 Mark]

Those blue pills work well, (so I'm told).

Welcome to the forum.

 

[LostKiwi]

Starting point.....
Look at what's listed as Current (F on Star). Ignore what's stored (f on Star).