OBD-II code · Network
U0109 Lost Communication with Fuel Pump Control Module
The Fuel Pump Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. Fuel-delivery control is lost, which can starve the engine of fuel. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.
Is it safe to drive with U0109?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyFuel pump module unpowered (often a fuse or relay)
- PossibleCAN wiring to FPCM broken
- Less likelyGateway module routing CAN messages incorrectly
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–5 h
- Emissions test
- Likely to fail
- Parts involved
- Fuel Pump Control Module, Can Bus Wiring
Related codes
- U0106Lost Communication with Glow Plug Control Module
- U0107Lost Communication with Throttle Actuator Control Module
- U0108Lost Communication With Alternative Fuel Control Module
- U010ALost Communication With Exhaust Gas Recirculation Control Module A
- U010BLost Communication With Exhaust Gas Recirculation Control Module B
- U010CLost Communication With Turbocharger/Supercharger Control Module A
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.