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Ml55 2002
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Discussion Starter · #1 ·
Hi all,

So my truck doesnt want to idle in D. Works out in N or R but after 2 or 3 seconds in D it stalls. Reading the codes I get -

P0443 Not Defined
Y58/1 (Purge Control Valve)

What is the purge valve ? Where is it located ? How come the truck is ok in R or N but stalls in D ?

Suggestions ?

Simon
 

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Ml55 2002
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Discussion Starter · #2 ·
So Ive found the purge valve. Sits on the bulkhead, has the acelerate cable connected to it and has a number of black vaccum pipes. I remember feeling this part and it used to pulse / vibrate, now it doesnt do that. So Ive got a feeling its dead jimmy :)

Can you guys go and feel your purge valves ! :) When the car is running do they pulse ? vibrate ?

Did a search and people are talking about split lines going to the tank and valves near the tank, anyone make any sense of that ?

£70 part, 10 days delivery !

Simon
 

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W163 and General M Gremlin
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8,573 Posts
If it isnt pulsing, it maybe kaput.
Any codes?

Check the stickies too - it's there.
Also, it's a different part for the ML55 - 2 lines vs. 1 line, I recall.
 

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Ml55 2002
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Discussion Starter · #5 ·
Thanks Chaps, as ever the forum has been a tremendous help. Ive ordered a new PV valve - A2124702793. I rang up my local Mercedes dealer and he gave me the correct part number. Ive found one on eBay and now have to wait 5/10 days.

Looking at the old one, it certainly doesn't pulse anymore. I used to notice / feel the pulsing on the old one as I have a vaccum leak once, the black pipe had somehow disconnected around the inlet area, and I remember feeling the PV vibrating and could feel it pulse.

Question, why does a broken PV only affect the car in D ? Works perfectly in N or R infact I reversed it home !! :) I noticed on the weekend that the car suddenly accelerated, similar to if the cruise control was on, whilst driving at 50mpg so I did have my suspicions that there was a pending issue on the horizon.
 

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2000 E 320 Wagon + 2002 ML 500 SUV
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Thanks Chaps, as ever the forum has been a tremendous help. Ive ordered a new PV valve - A2124702793. I rang up my local Mercedes dealer and he gave me the correct part number. Ive found one on eBay and now have to wait 5/10 days.

Looking at the old one, it certainly doesn't pulse anymore. I used to notice / feel the pulsing on the old one as I have a vaccum leak once, the black pipe had somehow disconnected around the inlet area, and I remember feeling the PV vibrating and could feel it pulse.

Question, why does a broken PV only affect the car in D ? Works perfectly in N or R infact I reversed it home !! :) I noticed on the weekend that the car suddenly accelerated, similar to if the cruise control was on, whilst driving at 50mpg so I did have my suspicions that there was a pending issue on the horizon.
Does the pulsing of this purge valve - indicating operation - occur at key on with or w/o engine start ?

I get that flashing light below fuel gauge - "leak in purge system" - P0446 I believe.

Admitedly Ive been ignoring it - it appears to have no negative performance impact - but was wondering if a 'smoke test' to locate leak was a good path forward ?

Thats why I ask about the running parameters for this electro purge valve are.

Thanks for any insight -

David in Texas
 

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Dallas, Texas
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Does the pulsing of this purge valve - indicating operation - occur at key on with or w/o engine start ?

I get that flashing light below fuel gauge - "leak in purge system" - P0446 I believe.

Admitedly Ive been ignoring it - it appears to have no negative performance impact - but was wondering if a 'smoke test' to locate leak was a good path forward ?

Thats why I ask about the running parameters for this electro purge valve are.

Thanks for any insight -

David in Texas
Engine has to run for at least two minutes at idle before purge valve starts operating.
Link in post #4 tests 31.0 - 34.0.
 

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Ml55 2002
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Discussion Starter · #8 ·
What is the purpose of a purge valve ? Why would it not working cause the truck to stall ?
 

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What is the purpose of a purge valve ? Why would it not working cause the truck to stall ?
If it is stuck open it acts like big vacuum leak that will affect idle. Post fuel trim values.

 
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