Evap issue P0440 / 190F08 BMW X5 Hybrid (F15) edrive40x

[amw111]

Hi friends,

I have been having an issue with my 2016 BMW X5 Hybrid (F15) edrive40x.

The service light on my ride has started to come on about 6 months ago. It throws the code P0440 - evap system (with my basic reader that comes with metromile). It came on at about 3/4 of a tank.

The first thing I did was replace the gas cap (OEM) - nothing changed.

Then I took it to my local mechanic who replaced the NON return valve (he said its the code 190F08) - they also cleared the codes so the engine light went off.

A few weeks later the light came back on (again at 3/4 of the tank) so I took it back to the mechanic and the same code came back on (190F08). Now he is saying the the vent valve (he also called it vent solenoid if that makes it clearer) needs to be replaced. He needed to order that from BMW and I needed the car so didnt leave it with the mechanic.

Now, surprisingly, after driving a few 100 miles the check engine light went off and didnt come back on for about 2-3 months (of regular driving with longer gas powered trips). I then went on vacation for 3 weeks and the car was idle for pretty much a month. After getting to about 3/4 of a tank the check engine light came back on again with the same code (P0440).

I haven't taken it back to the shop but wondering if it could be caused by a combination of irregular usage + stale gas? Whenever I drive little I almost exclusively use the 100% edrive mode and a tank sometimes lasts me 2-3 months.

Any thoughts on whether I should DIY any parts or just take it back to the mechanic and hope that the next replacement will permanently fix the issue?

Thank you!

[Tomcat_F15_STL]

Details:



I can understand the mechanic's confusion. This hybrid N20 engine does not have anything called a "vent valve."

If he has, in fact, replaced the "non-return valve" already - then, it may be this "insulation valve" as it is also part of the fuel ventilation system...

[amw111]

This is amazing - thanks so much.

Do you have thoughts on why the check engine light keeps resolving itself? Does that mean the valve sort of functions but under certain conditions it does not?

I went back to the reports I got from the mechanic and I realized I confused the two valves.

As of now the following was replaced --> vent solenoid / fuel tank vent valve / purge control valve. These three terms were used in the description and the invoice. The description includes that the vent valve was not sealing properly.

Does that make sense from your POV? Or was that a potentially unnecessary replacement?

As a next step, he proposed to replace the non return valve which based on your message above seems to make sense? Also included a screenshot from the latest diagnostic trouble code.

Is that something you think can / should be DIYed?

[amw111]

Originally Posted by Tomcat_F15_STL

Details:

Attachment 3132825

I can understand the mechanic's confusion. This hybrid N20 engine does not have anything called a "vent valve."

If he has, in fact, replaced the "non-return valve" already - then, it may be this "insulation valve" as it is also part of the fuel ventilation system...

Attachment 3132834

Maybe this is the vent valve they are referring to? https://www.bmwpartshub.com/oem-part...ljLWdhcw%3D%3D

Looks like the N20 has a vent valve - or am I misinterpreting this?

[Tomcat_F15_STL]

I believe you are correct in that this is the Vent-valve described in the diagnostics. For some reason, it did not turn up in my prior search.

I would go with this.



This should be entirely replaceable as a DIY. Of course, everyone has their own level of ability. First step is to find it!



It is probably iunder the engine air filter box.

[amw111]

Very helpful thanks. The return valve had been replaced and next would be the non return valve. Based on what you wrote before it sounds like that makes sense.

I guess I will go ahead with that.

Right now the check engine light has disappeared again so I will wait until it comes back on.

[Tomcat_F15_STL]

lol. The wonderful world of BMW. It’s a circus!

[pkbmwx5]

amw111
Did you ever figure out this issue? I have the EXACT same problem on exact same car- 2018 X5 40e.

I've replaced Tank Ventilation Valve. Code keeps coming back

Originally Posted by amw111

Very helpful thanks. The return valve had been replaced and next would be the non return valve. Based on what you wrote before it sounds like that makes sense.

I guess I will go ahead with that.

Right now the check engine light has disappeared again so I will wait until it comes back on.

[srybicki]

Same issue here.
Any updated

[dsfking]

Same. Any updates? Thanks.

[AdolfoMolinaM]

Hello everyone, this may be an old topic but I want to leave my contribution because I did not find the solution online to the fault 190F08.

After 5 months trying to solve the error, I was finally able to solve it. I changed the gas cap, purge valve, changed the DMTL pump, and checked all the pipes and seals, I also tested it with a smoke leak detector and everything was functional and no leaks.

I literally tried everything and gave up. After I tried everything I could, I ended up taking my BMW X3 F25 2017 N20 to a BMW specialized workshop. What they told me was to change the purge valve (again) for an original and new one. The one I had bought was original but used.

I decided to buy the new one and try again. But after 4 days the CEL Check engine light came back on with the same fault (190F08).

This frustrated me and I decided to check EVERYTHING again. In this case I also checked other additional components and found that the plugs of the two differential pressure sensors were swapped. I realized this because the two plugs have the same connection, they are next to each other BUT one of the plugs (which is after the throttle) has a clip on the cable to attach it to a part of the engine. Since they were in alternate positions, the clip was not attached anywhere and there was no way to hold it. When I saw that, I decided to change their position and look online for a picture of these sensors. There is one that says "3.5" and the other does not say anything. The 3.5 is high pressure so it goes on the intake side before the throttle, and the other one that does not say anything is low pressure and goes after the throttle.

When I changed them according to the internet picture and the correct way of the harnesses, I proceeded to turn on the vehicle and it threw a lot of errors and turned off. Then with ISTA software I reset the ADAPTATION VALUES of the DME so that it would recalibrate the sensors, the fuel mixture and the EVAP system.

And BOOOM, problem solved.

I think this is a common issue because the sensors look the same, have the same connection and are close to each other.

This whole problem was because some workshop swapped the sensors after disassembling that area of the engine and recalibrated the DME to work that way.

I hope this helps someone who is having the same problem.