DTC P1233: Fuel System Disabled Or Offline

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

P1233 - FUEL SYSTEM DISABLED OR OFFLINE

Description:	The PCM monitors the fuel pump monitor (FPM) circuit from the fuel pump driver module (FPDM). With the key on, the FPDM continuously sends a duty cycle signal to the PCM through the FPM circuit. The test fails if the PCM stops receiving the duty cycle signal.
Possible Causes:	Front inertia fuel shutoff (IFS) switch needs to be reset. Open FPDM ground circuit. Open VPWR to FPDM. Open or shorted FPM circuit (engine should start). Damaged front IFS switch. Damaged FPDM. Damaged PCM.
Diagnostic Aids:	The PCM expects to see one of the following duty cycle signals from the FPDM on the FPM circuit: 1) 50% (500 ms on, 500 ms off), all OK. 2) 25% (250 ms on, 750 ms off), FPDM 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 FPDM has detected a fault in the circuits between the FPDM and the fuel pump.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to Pinpoint Test KB .