Dear all, I have a 200E39 528i and my service engine soon light keeps coming on. I took her through a carwash and found that my gas flap had been forced open, ever since this SES light keeps going on. If I take gas cap off and re tighten it will go off and then come on various times later. happens at least twice every fill up and various lengh of time before it goes off again. ? is this a sensor fault. can I find an easy fix or is it to the shop?. any help thx

your best bet is go to a shop since that cel(check engine light) could mean anything i just took mine in thinking it was for a o2 sensor it turned out to be my thermostat. try to find a independent bmw garage they are usaully mor reasonable on prices i only paid 20 to look at my codes you can go to autozone and they can look at for free but just keep in mind it might not work with there obdII code reader my mechanic had to open the hood and read it off of the cannon plug looking thing on the fender.

Thx for the reply, I was told by the Dealer that the seal around my Gas Cap was bad. Fix will cost $17:00 thx for your help.