Engine Hesitating When Warm
 

I've had this W212 for about 5 weeks now. Over the past 3 weeks or so, I've noticed when car is started on a warm engine, it starts OK, but RPM drops as if engine wants to die off, but then it immediately comes back up to normal levels. Tonight, after car was started with engine temp around 40C, engine totally shut off right away. When I restarted, I had to push a little gas for it to stay running. I was able to drive home without any issues. When engine is cold, there are no issues!

I've done some reading as to what could be cause, it could be the crankshaft position sensor (CPS). I may have to run my own SDS to get some type of an answer, MAYBE!

My car is a PZEV and has 15 years warranty for emissions related failures. I just checked the warranty booklet and saw that CPS, among others, is a covered part. I take in car for service B1 on Saturday, so we'll see what they say!

Any stored codes? CEL on? For CPS etc you would typically get a code.

I would be curious to know what the dealer comes up with. The symptoms you mention can be related to a lot of things, more than can be listed here. Anything from fuel to ignition to PCM etc. The main thing I see is an issue described as all sensors go into closed loop.

I ran SDS tonight and no codes were present, no CEL either. All checked out fine, and that hesitation has not reoccured since that incident when car turned off a couple of days ago. I guess stealer will let me know, if anthing.