W204 p0123 throttle / pedal position sensor switch a circuit high

[RaMx]

A month ago my engine light came on I plugged in my OBD reader and got the above error which I cleared.
A week later I mentioned it to a mechanic who plugged his reader in and the error was there again even the engine light was not on.
He said its the throttle body which needs replacing and quoted me £350 to £400 for the work to carried out.
The car is running perfectly and I have driven 900 miles without any probs at all, the engine light is still off but if I plug my OBD reader in th error is still there if it's cleared it reappears after a while.
I have googled the error and see that there is a few things other than the throttle body that could cause the problem including the sensor in the pedal a broken wire or a short and a dirty throttle body housing.
Now I feel a bit dubious about the quote I was given as all other the other fixes could be somewhat cheaper.
Does anyone here know of a way of diagnosing the fault further or should I just leave it and see what happens..
If it turned out to be the pedal I could prob change that myself.

 

[mercy-b]

A month ago my engine light came on I plugged in my OBD reader and got the above error which I cleared.
A week later I mentioned it to a mechanic who plugged his reader in and the error was there again even the engine light was not on.
He said its the throttle body which needs replacing and quoted me £350 to £400 for the work to carried out.
The car is running perfectly and I have driven 900 miles without any probs at all, the engine light is still off but if I plug my OBD reader in th error is still there if it's cleared it reappears after a while.
I have googled the error and see that there is a few things other than the throttle body that could cause the problem including the sensor in the pedal a broken wire or a short and a dirty throttle body housing.
Now I feel a bit dubious about the quote I was given as all other the other fixes could be somewhat cheaper.
Does anyone here know of a way of diagnosing the fault further or should I just leave it and see what happens..
If it turned out to be the pedal I could prob change that myself.

Good evening,
i am having the exact same issue and have been told to replace the throttle body but as you say its abit pricey, did you have anymore luck in finding your issues ?
cheers

 

[mattkh]

....... to replace the throttle body but as you say its abit pricey,
cheers

How about cleaning the throttle first.

 

[RaMx]

Good evening,
i am having the exact same issue and have been told to replace the throttle body but as you say its abit pricey, did you have anymore luck in finding your issues ?
cheers

I left the fault to see if it reappeared and now it has been completly gone for six months..
I did change the peddle for a second hand one as that was a cheap try but the light came on after that.
Sorry I am not sure how to advise you further but my mecanic did tell me that the problem wasnt huge and to wait and see what happened.

 

[Gazwould]

How about cleaning the throttle first.

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