2001 S500 question on self adaptation
 

I'm working on the above listed car and am getting the following:

Self adaptation in lower partial load range, R bank/L bank.
Self adaptation in upper partial load range, R bank/L bank.

The actual values were all over 1.3. In addition, I'm getting a reading of 150dF on the intake air temperature sensor. Based on what I've been reading the temp sensor is integral to the AMM. The car has a little over 104k miles on it and is still on the original AMM.

I'm suspecting the AMM needs to be replaced. Any thoughts/comments are appreciated.

Oh yea, I'm seeing a slightly rough idle along with poor fuel economy. Check engine light comes on after a while. Plans are to test the AMM tomorrow.

Well it wouldn't be an uncommon failure, can you reset the adaptaion and see what it does after a road test? I assume you have a code/CEL for adaption exceeding limits as well. This was SO common back in the late 90s/early 00's
IAT is yes part of the MAF sensor. I don' tknow if the temp at 150 F would concern me unless it cold/blustery in GA this time of year?? Unless the engine is stone cold and you're sure it's not that hot in back of the engine at the time of testing. Seems reasonable, the MAF is pretty close and personal to the engine back there, will get hot.

Thanks Gilly, it was probably less than 95 dF under the hood during the testing.

I'll reset the adaptations and see what happens.

Air mass meter for sure, don't forget the rubber seals on the connector as well.

This is what I'm getting.

Next question. Is this something I need to purchase from the dealer ONLY? Note the O2 sensor readings above the adaptation info on the attached shot. I installed front O2 sensors that were not from the dealer and the only explanation I have is that is the issue with them.

No, Bosch is Bosch! Of course Bosch offers ONLY a complete MAS for that application.

I would think $170 would be a good wholesale cost.

Installed the new Bosch air flow sensor, reset adaptation and went for a 12 mile ride. Car runs as good as it ever has and the adaption is at around 1.02:). Also pulled throttle butterfly assembly out and cleaned it up. It was nasty at 103k miles. I would be interested in seeing what one of these look like out of one that runs on the autobahn the majority of time.

Thanks for the heads up on the two rubber seal rings:).

Got an easy one tomorrow - timing belt on a VW 1.8turbo.

Well drove it around a little and the check engine light came back on with misfire on cylinders 3, 4 and 5 (just read it off Autel MaxiDas for the time being). Runs badly at idle now with the ck engine light on. I'll look at it a little closer tomorrow.