Transient Check Engine Light

[Hakko]

This past Sunday, I forgot to close my gas cap door after filling up, thus setting off the CEL. I expected the light to go away after 36-48 hours, but it persisted until Thursday, so I went to Autozone to have the codes read. They were P2298, P1434, and P112d, all having to do with either the O2 sensor or the A/C coolant temp.

So I booked the X3 into BMW service, almost immediately after which it went off. :mad: Then, today, my wife had to take the X3 to pick our daughter up from camp -- a 3.5 hr drive -- because her car developed engine trouble just as she was heading out. She was probably 2 hours down the road, when she called to say the light was on again.

Is this a common occurrence with X3s in particular or BMWs in general? Should I be concerned, based on the codes generated? The car is a 2007 and only has 7500 mile on it.

[JBasham]

I had similar intermittent check engine light-ups on my 2006 X3.

I took it to the dealer and the rear O2 sensor was only operating intermittently. I'm pretty sure they figured that out through reading the fault codes, so you don't have to get it to the dealer with the light on for them to diagnose it.

They replaced it under warranty.

[Hakko]

Yep, they replaced the O2 sensor this morning. May just be my imagination, but pickup seems noticeably better.

[jcarlilesiu]

I believe the X3 has a designated "Check Gas Cap" light on the instrument panel between the fuel and temp gauge.

I don't think the X3 will through a CEL for a gas cap problem for future reference.

[Hakko]

I believe the X3 has a designated "Check Gas Cap" light on the instrument panel between the fuel and temp gauge.

I don't think the X3 will through a CEL for a gas cap problem for future reference.

Not the case for the 2007, AFAICT. I have definitely illuminated the CEL after failing to click the gas cap (my first fill-up) and after failing to close the cover properly.

[Vodka G]

similar issue...brought it in last month and they told me it was a 'gas cap' (aka the dealer is too busy to deal with me at that time)

the light is on again yesterday....so i am going to pull the codes but not erasing it to see what it is and then bring it in

04 with 64k miles

[jcarlilesiu]

Weird that BMW would remove this feature later in the production cycles.

The '04 has the light, I have never seen in illuminated as I have never failed to tighten the cap, but I would assume since the silouette is there that it would work.

Can you even see the "Check Gas Cap" light when the sun hits it just right to see the silouette?