SL55/63/65/R230 AMG: P202B-002


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What I'm seeing is ~900RPM on a warm start w/ a/c off when Spec is 650 +/- 50 RPM's. It will settle down to about 720RPM but it takes much longer than what DAS suggests should be 30 seconds.
I'm guessing that's triggering the CEL because in DAS under "Fault Causes" it says among other things "Requested idle speed exceeded by greater than 200 RPM " and also "requested idle speed not reached by greater than 100 RPM with in about 30 seconds"). I've reset the CEL and it returns after a few drive cycles.
I went through all of the tabs in DAS under that code. It suggests that the sensor (guessing that means the crankshaft position sensor???) be re-initialized after the Motor Mounts or Crankshaft position sensor are replaced. The crankshaft sensor was recently replaces about 18 months and 3k miles back. I've put about 1k miles on it after buying it 2 months ago and this is the first CEL I've had. I have done the motor mounts about 650 miles back (not sure how that plays into it??).
Using DAS I have "reinitialized the sensor", and I also applied the "Default Initialization to the Module" ( that's apparently the "ME28AMG" module in the upper corner of the screen, but all of this fall under the "ME SFI 2.8" ECU module) but the high idle speed doesn't seem to respond.
I seems that the cold idle does seem to have a bit of a "rumble", don't know if that's normal or not. It got new plugs and other services since I bought it too. I also pulled the throttle body recently and cleaned out the gunk...….certainly I moved the throttle plate in that process, but it doesn't seem that this had an effect as the CEL came on 200 miles later (I think). Per this string I did recheck the two hoses on the left Valve cover.....they look ok but they aren't really vacuum hoses so they shouldn't be critical here?
Other "Actual Values" from DAS that may offer a clue:
Throttle angle 0.3 degrees, Cam Shaft Hall Sensor "OK", Throttle Position Stop Position Learned "OK", M33 Electric Air Pump "OFF".
Any help or advice would be appreciated. Thanks.


Vacuum line (hidden connection) dislodged when changing the valve cover gaskets (driver side) at rear, accessed by removing the left side intake plenum.
This link is what clued me in.
https://forums.mbclub.co.uk/threads/...ix-diy.239905/
Unless you knew that this line was so easily dislodged, it would be nearly impossible no to pop this tube out when doing the valve cover gasket on that side.






