P2421 keeps returning on 07 Mercedes E63
Hi all, need some help with this 2007 MB E63 AMG. Its low mileage with just 45,000 miles. It first came in with code P2421 (Mechanical defect or Component Y58/1 Purge Control Valve Is Permanently Open) a while back and we smoke tested the entire EVAP system, no leaks found, and replaced the purge valve. Vehicle returned a while later and we had the same code. Again checked over the EVAP system, ended up finding a fuel leak at the fuel pump seal. Replaced that seal and all was good for months. Now the car is back last week, again smoke test the system and this time we found a very small leak from the vent valve that's integrated into the carbon canister. Replaced the canister with a new one from MB and a few days later the same code is back.
The purge valve seems to operate fine, it activates and allows vacuum to pass when clicking, holds vacuum when off. We've checked the circuitry to the purge valve, also no issues found. I talked to the head tech at a local MB dealer who's a friend, if he thought a software update on the ME might fix this. He said we can try, but that's not something he's come across on these models before that software would fix. I tried to update with Autel, but Autel will not update that ME.
There's nothing I can find on Identifix or Shopkey that is helpful… I asked the customer to come back with it next week after I've done some more research.
Any ideas would be appreciated.
Check your engine wiring harness for oil at the dme?
Hello Shane, Is there any chance the customer is overfilling the tank when they fuel up? It is a bad habit many people have. The need to stop fueling at the first “click” the station pump cuts off.
I checked on that. He said he doesn't top-up, and I know that his light will come on about every 2 days, even if he hasn't filled up.
what is the code set criteria for that code? How does the PCM know it’s the purge valve ? it says mechanical fault or purge valve stuck open. I wonder if you have a vacuum leak or mass airflow issue elsewhere that is tricking the pcm into setting the code.
Well, I would say that over time you have corrected several issues as they showed up. After all, a code is only a hint that a problem exists but not always is it directly a particular part. That being said, keep in mind that occasionally a problem can be operator inflicted. More than once I have run across a problem caused by the operator doing/carrying something in the vehicle that caused an…
Fuel tank pressure sensor can cause this issue. Look at sensor actual value with gas cap open, if it shows negative pressure, it's faulty.
I would agree with Noel dtech engineering did a pretty good video recently about similar issue
Good call Noel, When I saw that I remembered yesterday I had a Chevrolet truck come in with a EVAP vent valve code and I did exactly what you recommended, KOEO and cap off showed a consistent -1.5in. Customer declined further diag.
Most likely something that the computer uses to monitor that(fuel tank pressure sensor, etc) is probably reading incorrectly. I'd assume under testing the computer commands the vent valve closed and looks for fuel tank pressure to drop in a certain amount of time. I'd assume the fuel tank pressure is not reaching the vacuum level. In most situations the purge valve isnt allowing engine vaccum…
Couldn't an intermittently stuck open purge valve cause that code as well?
Unlikely the replacement purge valve would act just like the original did.
I would certainly think so. We've changed that valve more than once now, so I'm not eager to just keep repeating that, although I don't think we used a MB branded purge valve.
Oops sorry I missed that you replaced it already. Don't think we would have gone aftermarket on that part though.
Did you look for the direction of flow arrow on the purge valve. I found a VW had an aftermarket valve on it and the connector was 180 deg opposite direction so if installed in the same orientation the valve is installed backward.
This car has the Y58/1 purge valve at front (common failure item), the Y58/4 shut off valve on top of the charcoal canister and the B4/3 tank pressure sensor. when the Y58/4 shut off valve is replaced you also need the … wiring harness adapter as the new shut off has a reversed polarity from the original valve, when you buy the shut off valve … you have to get wire harness…
I was going to comment something similar Raul until I read all the posts and saw yours. on those adapter harness plugs though- there was a time when they were wired incorrectly from the factory. The new canister close valve is labeled (+) and (-). Use the wiring diagram and make sure that the 12v leads through the correct wire to the new valve. If it doesn’t, unpin the connector and swap the…
Thanks for the helpful information Raul. We did replace the updated wire harness adapter at the same time as the carbon canister. On the purge valve direction of flow, we paid attention to the arrows, also noted one connection is larger than the other. I'll verify that the polarity is correct when the vehicle returns. As for the B4/3 tank pressure sensor, the dealer can't find it for this exact…
OK, customer just reported back, happily, that its been 6 days and the check engine light hasn't returned. When he brought it back in I once again went over the entire system. I monitored the fuel tank pressure (this tank pressure sensor is built into the fuel pump, which we had already replaced with MB pump) and could see it working as I increased and released pressure using the tank cap as…