P1234 - Fuel Pump Driver Module Disabled Or Off Line

P1234 - FUEL PUMP DRIVER MODULE DISABLED OR OFF LINE

Description:	The powertrain control module (PCM) monitors the fuel pump monitor 2 (FPM2) circuit from the fuel pump driver module 2 (FPDM2). With the key ON, engine OFF or key ON, engine running the FPDM2 continuously sends a duty cycle signal to the PCM through the FPM2 circuit. The test fails if the PCM stops receiving the duty cycle signal.
Possible Causes:	Inertia fuel shutoff (IFS) switch needs to be reset Open FPDM2 ground circuit Open circuit to FPDM2 PWR RLY Open FPDM2 PWR circuit Open or short FPM2 circuit (engine should start) Damaged IFS switch Damaged FPDM2 PWR RLY Damaged FPDM2
Diagnostic Aids:	The PCM expects to see one of the following duty cycle signals from the FPDM2 on the FPM2 circuit: 1) 50% (500 ms on, 500 ms off), all OK. 2) 25% (250 ms on, 750 ms off), the FPDM2 did not receive a fuel pump (FP) duty cycle command from the PCM, or the duty cycle that was received was invalid. 3) 75% (750 ms on, 250 off), the FPDM2 detected a concern in the circuits between the FPDM2 and the fuel pump.
Application		Key On Engine Off	Key On Engine Running	Continuous Memory
All		refer to PINPOINT TEST KB .