Fuel Pump Driver Module Disabled Or Off Line
Table of contents
P1234 MERCURY 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
- Fuel Pump Driver Module (FPDM) circuit poor electrical connection
- Faulty Inertia Fuel Shutoff (IFS) switch
- Faulty Powertrain Control Module (PCM)
How do I fix code P1234 MERCURY?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- 1. Disconnect the inertia switch harness connector
- 2. Turn key to ON position (Engine OFF)
- 3. Measure voltage of circuit between inertia switch harness connector and ground
- 4. If battery voltage is found, replaced Inertia Switch
- 5. Clear codes.
Cost of diagnosing the P1234 MERCURY code
The cost of diagnosing the P1234 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1234 MERCURY Description
The Powertrain Control Module (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.