On a 94 Deville the Digital gas indicator flashes E all the time even when tank is full. Is there a module that controls this your fuel door won't open when you push the button either. checked fuses.?

I had the same problem with my 94 deville except it was just one of the fuses under the hood but i alos know that sometimes when this happens your ground wire (which should be under the car on the gas tank has came loose. I would check these things first. As for your fuel door i have the same problem so i dunno The gas sensor is located on the fuel pump inside the gas tank. One day my deville ran out of gas when it showed 4 gallons. A week or two later the fuel pump failed. The shop said I needed a new fuel pump. 700 Bucks. ouch