Diagnostic Resource Only
Note: Highway 71 Auto Parts provides this guide for diagnostic purposes only. We do not sell or service this specific module. We specialize exclusively in Engine (ECM/PCM), Transmission (TCM), and Body Control Modules (BCM). If your diagnostics point to an Engine or Transmission computer failure, contact us for a programmed replacement.
Why Your Fuel Pump Controller is Rotting
On many GM and Ford trucks, the Fuel Pump Control Module is mounted to the frame rail. This exposure leads to a unique failure mode that can leave you stranded on the highway.
The Aluminum Cancer
The FPCM housing is made of aluminum. When it sits against the steel frame of your truck, a process called Galvanic Corrosion occurs. Salt and water act as an electrolyte, eating through the module’s case until water hits the circuit board.
👨🔧 Warning: The “U0109” Code
“If you get a U0109 code (Lost Communication with FPCM), do NOT buy a fuel pump. That code means the computer can’t ‘talk’ to the module. A dead pump won’t cause a communication code—a dead module will.”
Prevention for the New Module:
- ✅ Plastic Spacers: When installing our new module, use nylon washers or spacers to keep the aluminum box from touching the steel frame directly.
- ✅ Dielectric Grease: Pack the connector with silicone grease to prevent water from entering the pins.
- ✅ Relocation: Some owners choose to move the module inside the spare tire area or higher on the frame to avoid road spray.