P0444 Code
 

Hello, my wife owns a BMW X5 4.8i, N62 V-8. While driving back from the zoo with my kids, she got the SES light, and called me in a panic. The car was driving okay, but still had her worried. I ran a code reader on it when I got home from work, and it popped a P0444 code for evaporative emissions control system faults. I cleared the code and test drove the vehicle, the light didn't reappear, and drivability was fine.

I guess this is fairly common among the N62 community (and with BMWs in general) but I can't seem to get a lot of information as it relates to the N62-powered X5. Does anyone have any insight or experience with this one? I would prefer to not throw random parts at it without narrowing it down.

PS: I did remove, clean, and retighten the gas cap, just in case.

My gas cap was over lubricated it seems. It was getting loose from vibration. Twice threw "very small leak" and once "large leak". I noticed the cap was not very tight after the first small leak error and was not turned on at all with the large leak. Upon further testing and diagnoses I discovered that it took almost no effort to twist off the cap.

Looked at the o ring and it was very well greased. I removed o-ring and flipped as well as wiped the grease down to just a film.

After that process it was 5x more difficult to twist off the cap (still not hard by any means) and no faults since and passed emissions.


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Two days later, still no reappearance of the SES light, so maybe it was a fluke, or maybe me wiping down and tightening the gas cap fixed it. Who knows...

Reappeared again. Anyone know of any solid leads or tests that I can try to avoid a costly trip to a dealer or Indy shop? I prefer to avoid throwing parts at a problem in the hopes that I hit the nail on the head on the first try.

P Code: P0444
Code: 2A19
Fault text: tank-venting valve (or tank-venting valve, activation)

Try to check the tank venting valve i don't know maybe it's got something to do with this. Check the attached PDF out of Rheingold, should be easy to do yourself.
Let us know if this helps.

and if cleaning doesen't work, you could try ordering this part to replace if you want to try before going to the dealer (make sure to use your own VIN to identify the part before ordering) :

http://bmwfans.info/parts-catalog/E7...alve#7537113_1

but of course could be something else causing the valve not to function correctly although the valve is good, do you have any other fault codes?

what this valve seems to be doing, googled tank valve :) :

Responding to concerns about the escape of hydrocarbons into the atmosphere we have developed a new generation of vent valves that use carefully calibrated springs to control a two way valve. This system is used on the TPV6 and the TPV8 In-Line valves. The benefits are that valve is shut when the engine is switched off so there is no trace of fuel smells in the garage. The valve will open to allow air into the tank to replace the volume of fuel that has been consumed. The valve will also open should any excessive pressure build up in the tank. This function safeguards the fuel system.

Thanks, Blizzard. I appreciate the link.

I assume that this is a fairly common issue on these cars, then, given the availability of a non-BMW sourced part to help the DIYer, who can't afford a trip to the BMW mechanic or stealer ship.

The link i posted is referencing the OE part not after market. That description is from a totally different valve, i just wanted to see what such a valve does. But you can order OE parts through other channels too not only from the stealership. You should try the cleaning first see if it helps.

Code detection is a funny thing....

So this code is "bad valve", right?

How do they decide it IS a bad valve? Some pressure sensors see something odd, decide "after x seconds the pressure should be Y- if that fails the valve is bad"

Such error trapping is based on "hoses never fail"...

Just be careful taking codes so literally. It COULD be the issue, but not always.