2009 w221 charcoal filter shut off valve
#1
2009 w221 charcoal filter shut off valve
got a code yesterday (p2422) stating that "evaporative emission system vent valve stuck closed". i removed the right back tire and removed the valve from the charcoal canister. powered the valve up with a dewalt battery and it works. tested the plug i have 12 volts but not ground on the plug. removed the plug, strpped the wires back, reconnected it to the valve and tested again with the dewalt battery just to make sure the plug wasn't bad. it still works.
so the problem is whatever controls the ground to the valve isnt giving it a ground.
any ideas.
thanks for the help
so the problem is whatever controls the ground to the valve isnt giving it a ground.
any ideas.
thanks for the help
#2
Super Member
That's because it is grounded by the engine control module. Ground will only be there if the engine control module decides to ground the valve. You need a scanner capable of doing actuations. You need to actuate the valve and then measure the voltage?? Also you can actually do a fuel leak test, only if your scanner is capable of doing the function. The most common problem with the W221 models is the Purge valve, which is under the hood right behind the driver's side headlight. This valve fails in the closed position and the computer thinks that is something else. But I am not saying that's what you need. The system needs to be tested fully in order to know what to replace.
#4
Super Member
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My personal experience is that a used laptop and a Tactrix passthrough device is enough to run Xentry & DAS. A really nice guy (yeah, I'm looking at YOU, @MBENZTECH ) helped me get it set up and working. That will let you do MOST of the functions a dealer service department can do. More if you know someone with an active M-B account to log in for some functions. It's not terribly difficult to do, there's a bit of a learning curve but it's pretty straightforward.
I had been looking at the Xentry/DAS setups available on Fleabay, but was reluctant to plow over $400 into a cheap Chinese imitation of the M-B C4 or C6 adapter. I have found that kind of hardware to be "iffy" at best. As it turns out, you don't even need it for 2006 and later model years.