That's my guess, since we had to replace stepper motors in two vehicles from GM. On some trucks there was a recall on those, but not on the cars with the same defective stepper motors. This is the guy I used.
Others you can check out on EBay.
Have a 2001 Jimmy. New fuel pump/sending unit installed. Ignition off, gauge goes to 1/2 - 3/4 full mark. Unlock any door or open any door or turn key to start position, gauge snaps back to empty position. Engine running, gauge stays at empty. Have tested voltage and resistance at sending unit, ok. All other gauges in cluster operational. Not sure what to check next.