2003 Fuel Gauge Problem

[Gov'sGuy]

I'm new to this Forum and I need a little help.

The fuel gauge on my 2003 Suburban will quickly register the loss of about 1/3 of a tank when going down a steep grade. It will slowly correct when on a flat or going up hill. If I'm on a flat I can shut off the ignition and open the door to shut down the electrical and it will correct immediately upon starting up again. Since I live in the Sierras it's become a real pain to have this happen all the time.

When I took it in to my dealer he replaced the sending unit, when this didn't fix it he just now just shrugs it off and says he can't fix it. Does anyone here know what this is?

Thanks, Al