Low fuel message when tank is full
 

My 2007 Malibu 4 cyl. with 60,000 miles has started to indicate that the fuel tank is empty when it's actually full. When I start the car, the fuel gauge shows full, but within 30 seconds the low fuel light comes on, the gauge needle drops to empty, and the message centre warning comes on. It will sometimes correct itself, but then fall to empty again. If I drive it down to less than 1/3 a tank, the gauge remains accurate until I drive the gas down to actual empty. A few times I've made a sudden stop, or abrupt turn and the gauge corrected itself for a while and then goes to empty again. The Check Engine light also comes on, and the error code is P0463 Fuel level sensor circuit high input...
Do I need to replace the gauge in the tank, or could it be a loose connection or pressure leak somewhere?
Thanks for your suggestions....
Vic

if it was a leak then you would probally smell gas, and have a noticable drop in miles per tank. the level sensor is esentaully a reostat, and can be removed from the tank. once is is removed you can manually check it with a DVM or a scope. i would start there.

sounds to me like its a connection problem.