So bought C300 2008 drove home worked perfectly fine. Had it parked for 2 days Went to start it up and all of a sudden, the check engine light was on went to back it out of the driveway was a really hard shift took it down the street noticed that it wasn't up shifting or down. Shifting Pretty much felt like it was in limp mode Check it with the code scanner. And a few weird things popped up Was pissed off gave it a day came back Check it with the code reader and all the codes had changed to different codes.. I'm no mechanic, so I just take it to mechanic who then in turn, told me that it needed a new battery and also it needed a new alternator so they charged me for all that trouble Drove the car home. from the shop worked fine, parked, it came out next day turn it on fine go to back out hard shift put in park shut off turn back on the check engine lights on again So I back it out and drive down the street anyway and realize that it is not upshifting or downshifting again. So what would be causing it to be supposedly? Fixed and drive perfectly fine for 1 day. And then you come back the next day and Allison. It's throwing up the check engine light again and not shifting. Right, it doesn't make sense why it would be perfectly fine. It has to be something computer-related. I'm assuming or am I missing something?

 

I also forgot to mention at the shop. They said that it needed a new battery and they found this out because the car was dead when I went to have it towed and the reason that was dead was because the battery was not good and was causing the outside lights to flash even when nobody was in the car until it drained the battery, so if you guys. Have that problem. It's probably a bad battery

 

Have ordered a new light switch as it intermittently causes a parasitic draw, but even a battery at 12.3V is giving me LIMP MODE and I will have to go to a Merc stealership to get the SUN diagnostics and a quote.

 

Any update about it?

 

Also interested, waiting for the result

 

Xynetics and not SUN diagnostic has revealed a resistance problem as cause of limp mode, cost AUS$2,000 for new accellerator pedal and contacts at harness. What I did then was I took off the pedal, removed the electrics and cleaned both male and female ends of contacts. Fixed. In the USA a recall for recent Mercs is under way, bot not here as we do not manage to sure car companies successfully with a weak ACCC.