Quality Control Valve?

[Slkgirl1]

Hi could anyone help with a likely solution please.
My 2011 C250 CDI AMG ( 107k) has yet another problem! Its now reluctant to change gear at around 2000 rpm but it will change if forced by pressing the accelerator. It’s an intermittent fault that seems to prompt the EML to come on mostly when the engine warms up but sometimes it comes on from the word go.
My friendly mechanic has plugged it in and has managed to eradicate one of the two faults shown by replacing the DPF sensor. His diagnostic machine ( not STAR) now only shows one fault as follows:-

Fault code P0252-18. ‘ The output for the quality control valve has a malfunction. The limit value has not been attained’

Can any of you guys with experience of the MB diagnostics say what this might mean please? The car hasn’t had a software update since I got it 5 years ago… might it be that?
Thanks so much. Any help is really appreciated.

 

[W1ghty]

Hi could anyone help with a likely solution please.
My 2011 C250 CDI AMG ( 107k) has yet another problem! Its now reluctant to change gear at around 2000 rpm but it will change if forced by pressing the accelerator. It’s an intermittent fault that seems to prompt the EML to come on mostly when the engine warms up but sometimes it comes on from the word go.
My friendly mechanic has plugged it in and has managed to eradicate one of the two faults shown by replacing the DPF sensor. His diagnostic machine ( not STAR) now only shows one fault as follows:-

Fault code P0252-18. ‘ The output for the quality control valve has a malfunction. The limit value has not been attained’

Can any of you guys with experience of the MB diagnostics say what this might mean please? The car hasn’t had a software update since I got it 5 years ago… might it be that?
Thanks so much. Any help is really appreciated.

Are there any MB specialist’s near you ?

 

[Larkone]

Sounds like your mechanics Star needs a proof reader

It should read Quantity Control Valve

This may help

No. P025218 malfuction 2014 Sprinter | Engine

Hello, i've got a mulfuction. No. P025218. Description - The output for the quantity control valve has a malfunction. The limit value for the current has not been attained.

forums.mbclub.co.uk

 

[BlackC55]

We have replaced a few now. It is indeed a quantity control valve.

 

[Slkgirl1]

Thank you very much W1ghty, Larkone and BlackC55, I really appreciate all your help ..and Larkone the clarification of the ‘typo’ on my local garages’ diagnostic machine changes things dramatically doesnt it?
Earlier this afternoon I booked the car into MD Motorcare who are MB specialists. They’re going to plug it into a STAR diagnostic reader next Friday. However, do you think that is a waste of £70 if the problem is now known to be the quantity control valve? I am trying to keep costs down because I am selling this car as soon as.. (because it keeps going wrong these days).
It’s interesting to know that these valves can be reconditioned. I’ll search to see if I can get one in the UK.
Thanks again.. you are stars!

 

[Slkgirl1]

After reading further I think it’s best for the Mercedes specialist near me (Wirral) to plug the car into STAR and take it from there. I’ll report back.

 

[BlackC55]

Thank you very much W1ghty, Larkone and BlackC55, I really appreciate all your help ..and Larkone the clarification of the ‘typo’ on my local garages’ diagnostic machine changes things dramatically doesnt it?
Earlier this afternoon I booked the car into MD Motorcare who are MB specialists. They’re going to plug it into a STAR diagnostic reader next Friday. However, do you think that is a waste of £70 if the problem is now known to be the quantity control valve? I am trying to keep costs down because I am selling this car as soon as.. (because it keeps going wrong these days).
It’s interesting to know that these valves can be reconditioned. I’ll search to see if I can get one in the UK.
Thanks again.. you are stars!

They can't be re-conditioned. New only and make sure its a genuine MB part.

 

[mersum1es]

STAR has individual tests for fuel components, ask them to do them

 

[Slkgirl1]

Hello again. Thanks BlackC55 and mersum1es for your further comments.
Well the car was plugged into a non STAR diagnostic machine because MB in their wisdom had decided to start a software update around 9am on Friday and it was still busy over a couple of hours later ( fantastic timing Mercedes ). The ‘other’ machine diagnosed a fault with the Quantity Control Valve… you guys were right.
I have been told that it’s a big job to fix.. approx 4.5 hours, because it’s awkward to get to.
Cost is £120 ish for the Mercedes valve (plus seals and gaskets £20 ish) and £270 labour , plus vat.
mersum1es , is your suggestion about individually testing fuel components still pertinent do you think… what would the extra info tell us please?

 

[mersum1es]

FQV is quite common culprit, though 'huge' amount of labor costs always put cost of diagnose other side of the scale... in OM64X engines valve change is 15-30 min job, OM651 fuel pump is located differently and I cannot estimate is 4,5hrs right

If two different diagnose machines are giving same fault, perhaps I would (hypotethically, because I have SDS of my own) go there and get FQV changed

 

[Slkgirl1]

Ok, thanks very much mersum1es.

 

[Slkgirl1]

Hi again guys,
Ive been driving around since replacing the diesel particulate filter and the engine mgt light has stayed off, even after 5 days of journeys varying between 5 miles and 50 miles. Could there be a link between the effects of this filter and the quantity control valve or is that a silly question?
Thank you.

 

[Slkgirl1]

Sorry, I meant to say ‘diesel particulate sensor’ not filter..

 

[Slkgirl1]

…and there have been none of the previous symptoms relating to reluctance to change down gears around 2200 revs.

 

[mersum1es]

No direct link but if DPF sensor has been giving false pressure reading and especially it has been fluctuating for some reason, prehaps that was triggering FQV fault because actual pressure couldn't follow suddenly changing demand... but you said #9 post FQV code was still coming a while after DPF sensor was changed? Or did they even check if code was current or stored/clear it and tried again?

 

[Slkgirl1]

Thanks again, mersum1es. When the car was plugged in ( after the Dpf sensor was replaced) it showed an historic fault with QCV.
After the dpf sensor was replaced the light did come on for a few days but MD Motorcare cleared it following their plug in.
Since then the light has never come back on again, and there have been none of the previous symptoms despite long and short journeys in the 10 days since.
Dare I hope that it has somehow resolved itself? I could do without a £520 bill !