anyone run into this problem? my 04 MCS with 43K mi just began displaying a Service Engine Soon light when the gas tank level reaches about one half. when I fill the tank the light goes out again. sounds like something to do with the evaporative emissions system but anyone dealt with this before? my searching found lots of threads on the SES light but not this issue.

thanks in advance!!!

 

Do you know what code is being thrown? I know I sometimes have an issue with my gas cap not being securely fastened.

GotMINI

 

thanks. no I have not been able to get a code reader hooked up.

I checked the gas cap first. even cleaned the interior sealing surfaces, etc. no help. I do need to find out the fault codes. just hoping someone had seen the issue before.

thanks

 

I have the same exact thing with my 04 S I bought a few days ago with a full tank. It hit a 1/2 tank today and the light came in. the guy I bought it from said that it sometimes happened when he accidently topped it off and got a little gas around the filler area. Hope some of you with more experience can enlighten and get the light out!

 

Just started happening to me too!! :::GRRRRRR:::

 

Codes! Need codes! Get 'em and narrow down the possible problem area.
Don't know where all you guys reside, but a lot of parts stores will now pull your codes for you. Call around.

 

Happened Again! I got a hair below 1/2 tank and it came on, I filled it then did the key on/hold the odo button down and it's off. No code reader here, maybe the BMW dealer...don't want to buy one, so one of you mainland guys that is having this exact issue, go to one of those parts stores that will read the code and report...gas cap tight...prev. owner said it happened to him only by over filling and topping off, wiping around the filler area fixed it.

 

Here's my experience with this. When my tank gets really low, like 1/8th of a tank, I get the SES light, and it goes off with a fill-up. I haven't been able to get the code, since both times it happened I wasn't really thinking a fill-up would make the SES light go off.

Could it be the summer gas formulation or ethanol causing problems when there's only a little fuel in the tank? I'm really clueless otherwise on this.

Ken

 

I *think* and I could be wrong that the vapor light comes on when there's not enough pressure in the tank... which could be a marginally sealing gas cap, a leak somewhere (hope not!) or a marginally faulty pressure sensor. Atmospheric conditions can affect it I would guess, humidity, air pressure, but not sure how much.

As to getting a reader. I know Advance Auto and Autozone will let you borrow a code reader so you can scan your own car. Sometimes they do it for you. Napa may also, but not sure. Go to your local parts store and ask, you may be pleasantly surprised.

Your best bet though is to replace the gas cap and see if that cures the problem.

 

I hooked up my new code reader because i was having similar issues got a code of PO442 using my INNOVA code reader. The 42 identifies the part but cant figure out which part that is...any help??

 

For more information, do a forum search on P0442 (that's a zero, not the letter O).