Question Details

After a minute of driving my ML 270 appears to drop into a safe mode where it accelerates very slowly, not to exceed 2000 rpm until it is in 5th gear. No matter which gear it is in, it will not exceed 3000 rpm.
This appears to be a computer "mode" that it gets into.
I understand that this is a common issue as a friend of mine has the same problem with the same car.

Comments

Profile picture for user MercedesMedic

MercedesMedic  9 months 1 week ago

I would check the 13 pin connector. Oil leaks from the transmission due to the fact that the O ring on the connector becomes brittle over time. http://www.mercedesmedic.com/722-6-transmission-plug-diy/

Also check the transmission fluid level. If the level is slighlty low, it can do what you describe. It's because after you drive for a few minuttes or when you go around a curve, oil gets pushed to the side and there is not enought fluid to be picked up at the transmission oil pan. This can send the transmission into limp mode. Have had this happened before.

Lastly, you need to check the codes. If the check engine light is on, read those codes. Ideally you should read the codes from the Transmission Control Unit TCU becasue often you will have a code on the TCU and not in the Engine Control Unit (ECU).


Profile picture for user MercedesMedic

MercedesMedic  9 months 1 week ago

Check transmission fluid level and 13 pin conentor as stated above.