Originally Posted by PROSTO.

Hi, Im having a problem with a check engine light on my 2009 x5 3.0. For the past few months the light has been going on and off from time to time. Sometimes I would get a message to tighten up the gas cap followed by a cel on the dash. Sometimes the light will go off for few days, sometimes it says on for a week. I replaced the gas cap and cleared the codes and 2 days lighten I get the same message to tighten the cap followed by a cel. Im thinking it might be my DMTL pump but Im not exactly sure where is the bump and how to replace it. Is it behind the liner by the passenger rear wheel? What else besides a pump or a bad cap could be wrong? BTW is this the correct part? Thanks for your help.

http://www.ecstuning.com/BMW-E70-X5_.../Pump/ES37298/