M271 intermittent throttle issues

May 14, 2021 | 08:11 AM

Niko_

Thread Starter

Newbie

Joined: May 2021

Posts: 1

Likes: 0

From: Sofia, Bulgaria

W203 C200

M271 intermittent ESP and throttle issues. Not detected with diagnostics

Hi all! I need your help.
I have C200 with M271 (163hp), with very strange behavior for the last 2 weeks of driving and 1k+ km - I can't get a pattern. There are days when the engine runs like a charm. Other days I can barely drive it.
For example

Few days ago rough idle and almost each time I stop the car, the RPMs drop and the engine shuts down (automatic transmission). It goes off before the full stop - like when I am running with 5km/h. If it doesn't go off, the RPMs drop to ~500 and then they start moving up and down with ~100
yesterday - no issues - working like a charm from cold start, through warm starts during the entire day
today - on cold start, the RMPs went to ~1800 and no throttle response, ESP warning on the display asking me to go to a service. After about 7-8 continuous restarts of the engine it started working fine. After some driving check engine light goes on and I get the errors:
P0638 (Throttle Acutuator Control Range/Performance Bank1),
P0120 (Throttle/Pedal Posotion Sensor/Switch A Circuit),
P0101 (Mass or Volume Air Flow Circuit Range/Performance problem) - all above as critical
+ P2001 (NOx Trap Efficiency Below Threshold Bank 2),
P2009 (Intake Manf Runner Control Circuit Low Bank 1 a),
P2032 (Exhaust Gas Temperature Sensor Circuit Low Bank1 Sensor 2),
P2029 (Fuel Fired Heater Disabled)
The last 4 faults are gray (They are not critical and should not affect the engine's performance according to the OBD diagnostics).
When the CEL is on, the engine works a bit rough - not as smooth as it usually goes. However there was no RPM change or anything - just a bit rough.

Clearing all faults with MB STAR allows the car to start properly. After that when reducing the speed while driving in the city, first the ESP warning on the display appears and after that - all those errors.
Nothing ESP related is visible through STAR, only the error above (sometimes not all of them are present all the time, but there are cases when in addition to those there is a misfire in all cylinders)

So far changed parts are:

Gas pedal
Throttle body
Coils, sparks, cables, plugs
MAF sensor
All vacuums checked for leaks - new hoses and one way valves where applicable
The chain and wheels (timing valves I think is the name) were replaced more than 30k ago - no issues from that standpoint.
all the issues I get are some time AFTER changing all those parts... The error codes are telling me to change them again [img]data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7[/img]

To me it seems like something mechanical or small electrical issue, but don't know where to look. The main problem is that after ESP warning on the display, there is no ESP dedicated error - only the errors already listed. Seems like something is causing those errors, but how to find where it comes from?

Last edited by Niko_; Jun 4, 2021 at 11:40 AM. Reason: Update with more details

Oct 23, 2024 | 01:10 PM

viktorbenz

Newbie

Joined: Oct 2024

Posts: 1

Likes: 0

Any solution?

Hello,

I’m facing similar issue with 1.8 kompressor, when I’m starting the car the RPM is going up and dow between 1300 and 1700 with ESP warning as well, no reaction to the throttle pedal whatsoever

did you find any solution?

thanks for your time in advance

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