The ASD (auto shut down) relay is located inside the Power Distribution Center. It might have a problem, try swapping the ASD relay with another like the horn relay which is the same type of relay. Relays that have the same size inside the PDC are all the same and interchangeable.
Other possible sources of a 42 DTC...
An open or shorted condition detected in the auto shutdown relay circuit.
An open condition detected in the ASD relay output circuit.
An open or shorted condition detected in the fuel pump relay control circuit.
An open circuit between PCM and fuel gauge sending unit.
Circuit shorted to voltage between PCM and fuel gauge sending unit.
No movement of fuel level sender detected.
(I wish I was only 42!