KB1 DTC P1233 OR P1234: IS DTC P1233 OR P1234 PRESENT IN KEY ON ENGINE OFF SELF TEST
Diagnostic Trouble Code (DTC) P1233 or P1234 indicates that the powertrain control module (PCM) has stopped receiving diagnostic information from the fuel pump driver module (FPDM). The FPDM diagnostic information is sent to the PCM as a duty cycle on the Fuel Pump Monitor (FPM) circuit. This is due to either an intermittent or hard fault concern. The only difference between the DTC P1233 and P1234 is that the P1233 is an MIL DTC.
Inertia fuel shutoff (IFS) switch needs to be reset.
Open FPDM ground circuit.
Open or shorted FPM circuit.