i own a 2000 deville and the gas guage is always showing full....i went to the dealer but they told me it could be a bunch of different things because it is electronic....anyone ever had this problem or heard of this problem? any advise would help......
thanks

 

Never on my Cadillac but on my GMC Suburban. The sensor is in the sending unit which is in the tank. It was a big job on the GMC.I started using the trip odometer when I got gasand figured out how far I could go on the gas I had. It is a pain, you'll need to fix it.

 

I own a 99 DeVille and my digital gas gauge just started acting up.Recently after I fill the tank, it counts down from F to 18 to 17, etc all the way down to about 7. Then is starts counting up to 8, then 9, then 10 and so on.

The last week,with less than 1/2 a tank of gas, it shows I have 15 gallons and then begins counting up.

I would love to get the gauge fixed.

Is my problem a sensor unit in the gas tank or a electronic circuit board that needs to be replaced ?

 

You may have figured this out by now. It's most likely the sending unit in the gas tank. Had mine replaced after having exactly the same problem with guage fluctuations. $600, and that was from an independent Cad specialist. He said the sending unit corrodes over time due to the type of bimetals they use. Only the most expensive cars of the world use a better one. It's something in gas formulations these days. You have no recourse but to have the unit replaced.