My W212 E200 changing gears at high revs and limp mode is off

[D2028]

Should be reading over 14v with engine running and alternator working properly?

 

[muddym2002]

I have a similar issue. I think it's linked to the Eco mode. If I drive in Eco mode it happens when start/stop activates. The car jerks when it tries to start and I get the message 'Pre safe functions limited'. It then changes gear in high revs until I turn off car and start again.

Took the car to the Merc specialist and they are stumped. Dpf has been cleaned and booster pipe changed yet issue remains. Any advise is much appreciated.

Thanks

 

[Stocious]

As I said, maybe it's not just one issue? But just guesses at arm's length.

12.4V seems low from memory. Should a healthy battery be around 12.7V?

It should be 12.7v like you stated.

 

[MrGreedy]

Yes, it seems to be about 75% charged as far as I read online. Is there a possibility that the battery will cause the problem that I face or it has something to do with?

Mercs tend to be very sensitive to battery voltage and condition. Either your battery needs a very good charge, or the battery is beyond its serviceable life and not capable of being charged AND holding that charge for several weeks if not used.

Give the battery a good charge with a quality charger, and see how the car behaves, plus monitor if the battery can hold the voltage over a few days. If the battery holds voltage, at least that is ruled out. If it can't hold voltage, then you have a battery issue that might well cause at least some of the symptoms you have listed.

But again, this is arm's length guessing, and you might have more than one issue. The reason I'm focusing on the battery, is it is a common cause of some of those issues, and a charge can be a cheap DIY test/fix (VERY CAREFULLY check the correct polarity for charging, as on my Merc the leads aren't coloured red and black; they are all black). If the battery needs to be replaced, again, this can be a quick, relatively inexpensive DIY if you know what you are doing.

 

[D2028]

It’s not normal. Something is wrong but hopefully any sensor fault. Did you manage to find your problem?

Haven’t found the problem yet, what about you?

 

[amgv12power]

Sounds like you need to get the cord scanned as you may still be in some problem mode