I just recently purchase my Audi. Ever since bought it I have the open gas lid light that appears on my screen. I've made sure that its been shut but it still flashes that its open. I also just recently noticed that my gas gauge might be off. I filled the gas tank all the way up but its only registering 3/4's of a tank of gas. When I filled it up the gauge registered 1/4 and I put as much gas in the tank that it would let me and it only needed 10.8 gallons, which makes no sense to me.. I was wondering if anyone has any ideas or if this has happened to anyone before??

 

You might need a new gas cap. Find a B6 buddy and ask to swap caps for a bit to see if that's the issue. If it isn't sealing it's either you or it.

The improper fuel reading is an issue with the sensor in the gas tank. It's happened before but it's not something I've seen an awful lot.

 

I can pick the gas cap up. I made sure it was tight everytime I've filled up. I will try and find a gas sensor, or if it is something that I am unable to do than I will take it in to get done.
Also I have an OBDII tool that I've used on other cars. I was wondering if this would tell me about the issue with the gas sensor or gas cap issue? I thought that this only works when the check engine light comes on, but I know that if you leave the gas cap off of your car and drive, typically the check engine light comes on?

 

Well out of no where yesterday the gas gauge started reading the correct amount of gas in my gas tank.. Not sure why this happened, but free is the best price for this fix.
I still need to find some time out of my day to see if I can pick up a new gas cap. However I thought that it was the gas door sensor that would cause that gas symbol to show up in the monitor rather than the cap, or I can be wrong..

 

I drove away once without replacing the gas cap and the dashboard didn't let me get too far. It clearly indicated the cap. The gas flap being open is a different dash light. I guess I misunderstood you and you have the flap open warning. Yep, that is either the sensor or something not allowing it to actually close. My apologies.

 

Hey SoldierBoy -

My A4 does the same thing every now and then. The dealer I bought it from replaced the gas cap with a brand new one, and it still did it. The indicator you're getting is definitely for the filler door (the top view of the car with the gas pump picture at the bottom right). With it still on when I left the dealership, they promised me that the computer had to take some time to reset, then it would be alright, and it was so. Two weeks later, though, it came back, lasted for a couple days, then went away again. So it's sporadic, and only an annoyance really. Doesn't seem to be anything crucial to operation of the car, and you can clear it just by hitting a button on the windshield wiper stick. If you find anything out about it, please post it on here and let me know, otherwise, I'm just gonna deal with it.

- bz

 

I wonder how difficult it is to replace the fuel gauge sensor? Has anyone done this before?
I also need to replace the fuel door sensor.