U0109🔧 Vehicle network (CAN bus) and fuel pump control moduleStop and fix promptly

U0109: Lost Communication With Fuel Pump Control Module (Meaning, Causes, Fixes)

Reviewed 2026-10-23 · Based on 4 cited source(s)

What U0109 means

Many newer vehicles with a returnless fuel system use a separate fuel pump control module to run the fuel pump. KBB explains that the FPCM manages most of the fuel delivery process but relies on signals from other modules to know when to run the pump and how much fuel to deliver. OBD-Codes.com says the FPCM runs the pump based on information from the powertrain control module (PCM), so if no information arrives, the pump won't run. The modules talk to each other over a two-wire network called the controller area network (CAN bus). U0109 sets when the FPCM and the other modules aren't communicating. RepairPal defines it as Lost Communication With Fuel Pump Control Module, and KBB notes that some vehicles call it Fuel Pump Control Module A. OBD-Codes.com says it is a generic code found on most makes, including Dodge, Ram, Chevrolet, Ford, GMC and Volkswagen, and both OBD-Codes.com and KBB say it is more common on gasoline engines, though some diesels use these modules too. The sources disagree on severity: RepairPal rates U0109 Moderate, while KBB calls it extremely serious and says the car usually won't start. They also disagree on how often the module itself is to blame: KBB lists a faulty or unprogrammed FPCM as a common cause, while OBD-Codes.com says a faulty module is rare and that the most common failure is a loss of power or ground. Ford's Special Service Message 51306 says some 2018-2023 F-150, Expedition, Navigator, Transit, Explorer and Aviator vehicles can set U0109 (often with P0627, P025A, P025B, P00C6 or P008A) because of a partly disconnected FPCM connector, pushed-out or damaged pins, or loose or corroded grounds, and tells technicians to check those before replacing any parts. Related codes include P025A (fuel pump module control circuit), P0627 (fuel pump control circuit) and U0100 (lost communication with the engine computer).

Severity: can I keep driving?

Stop and fix promptly

Treat it as serious. The sources disagree on how urgent U0109 is: RepairPal rates it Moderate, but KBB calls it extremely serious and says you usually can't drive with it active, because the engine often cranks but won't start when the fuel pump gets no commands. OBD-Codes.com also lists a crank-no-start, hesitation, lack of power and misfiring. If the engine stumbles, loses power or won't start, stop driving and have it towed or diagnosed rather than risk stalling in traffic.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Loss of power or ground to the FPCM, including blown fuses and loose or corroded ground connections, which OBD-Codes.com calls the most common failure (OBD-Codes.com, Ford SSM 51306)
  2. A loose, partly disconnected or damaged FPCM connector, including pushed-out or damaged pins (KBB, Ford SSM 51306)
  3. Damaged or shorted wiring in the FPCM harness (OBD-Codes.com, KBB)
  4. An open or shorted CAN bus circuit or another network problem, especially when other modules also report lost communication (OBD-Codes.com, KBB)
  5. A faulty FPCM or one that needs reprogramming; KBB calls this common, OBD-Codes.com says it is rare (OBD-Codes.com, KBB)
  6. Rarely, a problem with the PCM itself (KBB)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Check for other codes first. OBD-Codes.com says any network, battery or ignition codes should be diagnosed before U0109 to avoid a misdiagnosis.
  2. Check for technical service bulletins or special service messages for your vehicle; for example, Ford SSM 51306 covers U0109 on several 2018-2023 Ford and Lincoln models (OBD-Codes.com, Ford SSM 51306).
  3. Check the fuses that power the FPCM (OBD-Codes.com).
  4. Find the FPCM and its ground points using a repair guide, then make sure the grounds are clean and tight and the FPCM connector is fully seated (OBD-Codes.com, Ford SSM 51306).
  5. With the negative battery cable disconnected, unplug the FPCM connector and look for corrosion, burnt or pushed-out pins, and rubbed or melted wiring (OBD-Codes.com, Ford SSM 51306).
  6. After any repair, clear the codes and see if U0109 comes back (OBD-Codes.com).

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • The car cranks but won't start, or stalls or runs poorly with U0109; KBB says you'll usually need a tow (KBB)
  • Power, ground and connector checks pass and the code keeps coming back, which calls for network testing with a multimeter and wiring diagrams (OBD-Codes.com, KBB)
  • Several modules report lost communication, pointing to the CAN bus network (KBB)
  • The FPCM needs reprogramming or replacement with professional scan tools (OBD-Codes.com, KBB)

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Is U0109 serious?

Often, yes. RepairPal rates it Moderate, but KBB calls it extremely serious because the fuel pump may not run, so the car usually cranks but won't start. If the engine does run, OBD-Codes.com and KBB list hesitation, lack of power and misfiring.

Can I drive with U0109?

KBB says you usually can't, because the code typically causes a no-start, and that you shouldn't drive if it's active since problems can get worse without warning. Have the car towed or diagnosed.

Do I need a new fuel pump control module for U0109?

Not necessarily. OBD-Codes.com says the most common failure is a loss of power or ground and that a bad module is rare, and Ford's SSM 51306 tells technicians to check the FPCM connector, pins and grounds before replacing anything. KBB, however, lists a faulty or unprogrammed module as a common cause, so have it tested first.

How much does it cost to fix U0109?

None of these sources gives a repair cost. It can range from replacing a fuse or cleaning a ground to repairing wiring or reprogramming or replacing the FPCM, so get a diagnosis or a written estimate first.

Sources

  1. OBD-Codes.com: U0109 Lost Communication with Fuel Pump Control Module (FPCM) (Randy Worner, ASE Certified Master Technician)
  2. KBB: U0109 Lost Communication With Fuel Pump Control Module A (reviewed by Gary Hardesty)
  3. RepairPal: U0109 Lost Communication With Fuel Pump Control Module (rated Moderate)
  4. Ford Special Service Message 51306: Fuel Pump Control Module diagnostic guide, 2018-2023 Ford and Lincoln (via dot.report)

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.