C200 Throttle no response and idle up & down

[hellgrace5]

Hi.

Currently my C200's idle is going up and down. Once I slightly press on the throttle pedal the idle will get even more aggressive up and down.

The throttle itself too has no response. No matter how i depress it the engine is not revving up.

Scanned with a MB Star, it has no fault.

What could have caused this ?

 

[jonathanc]

Hi

This sounds like it might be a problem with the throttle body, assuming it is electronic as they are on the w203 onwards (maybe w202 as well). It might be worth trying to reset the throttle body, I believe there is a procedure to do this, the one that works for my 203 is:

Turn on ignition (ie all warning lights on but engine not running)
Push the accelerator to the floor and hold for 5 secs
Turn off ignition but leave key in
Wait 2 minutes


If not it may be gunked up and cannot move the throttle butterfly- have a look at it and check. Other options could be an air leak or another sensor fault although I suspect STAR would show a fault if it was a sensor.

Regards

 

[hellgrace5]

I've clean the throttle flap. Its not jammed and its clean. Theres no fault in Star so I assume its not a sensor fault.

I'll try the reset procedure and update.

Thanks!

 

[jonathanc]

Hope it works.

Is this a Kompressor model - I had a problem running with ours and it turned out that where the MAF had been changed they hadn't fitted the hoses properly so it was leaking air meaning it would hesitate and splutter sometimes and felt like it was running weak.

Cheers

 

[x332race]

Split in air supply pipework?
Loose vacuum pipe?

 

[hellgrace5]

Its a normal c200. no Kompressor

 

[hellgrace5]

I've gone tru all vacuum pipes. No leak.

Could a leaking vacuum pipe cause throttle no response at all ?

 

[grober]

What age is the car? W202 or W203? These can have an electronic throttle so no throttle cable Something may have gone wrong with the physical link between the throttle pedal assembly and the electronic module ?

 

[ched999uk]

It could be the throttle position sensor. I would guess a STAR can give positional readings when you press the throttle?

 

[hellgrace5]

Its a W202 C200. Will check the readings and update. Thanks

 

[JohnnyW202]

Was this problem ever resolved?

I've got the exact same symptoms after having my battery discharged for a number of days, charging it and refitting.

Many Thanks.

 

[jefrs]

Was this problem ever resolved?

I've got the exact same symptoms after having my battery discharged for a number of days, charging it and refitting.

Many Thanks.

Try the reset given in post #2 above.
You can release the throttle after turning to "0" but do not operate any electricals, even opening the door for that 2 minutes.

Steering reset is max lock and hold for a few seconds, each way a few times.

Btw they do not like having the battery disconnected, I would charge it in-situ connected up, (and top up the cells with demin battery water).

Also to get the windows reset, nudge them to top and bottom and hold the button for a few seconds until another click happens. So the system now knows where top & bottom are.

 

[hotrodjon]

I have had my '97 C180 battery disconnected quite a few times with no problem at all.

 

[JohnnyW202]

Tried both the steering lock and throttle reset multiple times.

Doesn't the throttle procedure, just erase the gearbox adaptations?

I haven't touched anything engine related...

The spark plugs, oil and atf were recently changed but the car was fine prior to these service items... The problem has occured since the battery went dead, was removed, charged and replaced.

Any more ideas?

The throttle won't rev at all it gets as far as 1,000rpm then starts hunting.

ASR/BAS and no other lights.

 

[JohnnyW202]

SOLVED! something just gave after 20 mins, started no light and revs, was one of these procedures. Many Thanks.

 

[jefrs]

I have had my '97 C180 battery disconnected quite a few times with no problem at all.

Yeah but... you do have to reset everything.

If you haven't got any major faults, it's not a big issue, but you do have to go round resetting the windows and radio-code and ...
It's almost worth hooking up a 12V backup battery to the jumper points.