P1234 – Fuel Pump Control Module Disabled or Offline

P1234 Possible Causes

• Inertia Fuel Shutoff (IFS) switch needs to be reset
• Faulty Fuel Pump Driver Module (FPDM)
• Fuel Pump Driver Module (FPDM) harness is open or shorted
• Poor electrical connection in the Fuel Pump Driver Module (FPDM) circuit
• Faulty Inertia Fuel Shutoff (IFS) switch
• Faulty Powertrain Control Module (PCM)

How to fix code P1234?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

• Engine light on (or service engine soon warning light)

The Powertrain Control Module (PCM) monitors the Fuel Pump Monitor (FPM) circuit from the Fuel Pump Driver Module (FPDM). When the key is turned on, the FPDM continuously sends a duty cycle signal to the PCM via the FPM circuit. The test fails if the PCM stops receiving the duty cycle signal.