The petrol gauge is not working?

It could either be the gauge in the dash or the sender unit in the fuel tank.

My 2001 bonny would read from full--- to 1/2 full tank, below 1/2 no reading, a new sending unit from GM will cost you $600.... but you can order a kit from GM that cost $40 to repair it The kit comes with a new sending unit trunk seal, a small circuit board, and a small plastic swiper arm, i just switched arms, the tiny metal fingers on the old one had worn away, unit works great.