"SERVICE ENGINE SOON"

[Skimo100]

Originally Posted by JCL

If it isn't the gas cap, then I am back to my original second choice, a sensor. Could be a vacuum line or something similar, but in any case, it is time to take it to the dealer. I wouldn't reset it, I would leave it latched so there is something for the dealer to look into.

I had an intermittent SES light on my new 535i. I reset it by restarting the engine each time. It came back several more times. Booked it into the dealer. They found a vacuum line that was collapsing with high vacuum. I asked how they located it; there was a TIB on that specific vacuum line. I would never have found it by poking around. I was just glad it wasn't a fuel pump or something major. Sometimes it is just better to let the dealer do their thing. It is under warranty, just take it in.

Just my $0.02

The thing that puzzels me is, if the fault was a constant one why doesn't it come back as soon as I reset it or at least a few minutes after I reset it? It appears to happen right after I filled the gas tank (about a day later or so). A 2007 X3 with a collapsed vacuum line?.....could happen but very odd.