flaco

So I heard a faint 'whine' the other day in the garage, thought it was the neighbours... not.

Morning after, the garage had HEAVY gas fumes... scary! I had just filled the tank, so I didn't think much about it. Prob overfilled the tank.

That night, the whine was there, and morning after there were gas fumes. That night I decided to hear closely, and it was coming from the gas tank! Pulled the fuel pump fuse (engine fusebox) and whine was gone... WTF.

Reading through vida I found the pump is controlled by no less than 3 computers... the engine module tells the fuel pump module what pressure is required. The engine module also tells the central computer CEM to turn on/off power to the pump & pump module. I dissasembled the CEM tonight, and found the typical relays that eventually fail due to sticky contacts. While playing with the boards I noticed the contacts had opened, so back into the car it went... Problem solved - for now.

I was able to find the exact relays online so I ordered two and will be replacing them in the following days. What's scary is that I found evidence of water corrosion in the top CEM board. Water seems to drip from the wipers compartment right on top of the CEM, although no visible water traces were found. I don't see any other way for water to get in there, so I'll be using some RTV as well, after I replace the relays and assemble everything back together. The sunroof drains were cleaned about a month ago (they were pretty much clean anyway, only some minor crud in there).

The CEM is ~$600 from tasca, and it REQUIRES a dealer to reprogram everything (CEM has the car's VIN, inmobilizer codes, etc, etc) so don't even want to think how much they'll want for the job.

I've had the xc90 for a little over 3 months now, and it's a nice car, but seems electronics are the weak spot...

Seems fuel pumps are also a weak link... Could it be that the CEM is the actual culprit for keeping it running 24/7? BTW only the 'primer' pump was running, as the 'main' pump is controlled by the pump computer...

I'm thinking the gas smell means some sort of leak is present, although I can see how keeping the priming pump running could force gas past the pump gasket.... Before this occurence, no gas smells have ever been present in the car. No gas spots were found in the garage floor / under the car.