Fuel Gauges on GM SUV's

Two fuel gauges on our GM SUV’s have failed at different times–a 2001 YUKON XL and a 2005 Trailblazer. Both had less than 100k miles on them. My wife says it is because I ‘over-filled’ the tank–I happened to be at the ‘nozzle’ just prior to them acting strangely–though I am almost always at the nozzle. I say it’s because GM has a problem with it’s fuel tank modules/parts and has nothing to do with over-filling. Who’s right?

Over-filling the tank, while a very bad practice, has absolutely no affect on the fuel gauge.

Thanks for the reply. BTW, I don’t agree that I over-fill. I just get the read out to the next whole amount–usually 50 cents or a dollar, which with today’s prices isn’t a whole lot of gas. Why is it bad otherwise?

Topping off a gas tank can allow liquid gasoline to make its way into the vapor recovery system, which is not designed for liquid. This can ruin the charcoal canister, which is very expensive to replace.

A few cents worth of gasoline is not likely to over-fill the tank, but some people keep adding and adding until it won’t take any more. THAT’S over-filling, but it still has nothing to do with the gauge.

I understand, makes sense. Thank you kindly for the concise reply.

There is a problem with the sending units.

I have a 06 Trailblazer and the sending unit had to be replaced while it was under warranty. Now it has about 30,000 miles since the sending unit was replaced and it has failed again.

I have talked to a GM tech that I know and he says they know what the problem is but GM hasn’t redesigned the sending units to fix the problem.