U0109Lost Communication With Fuel Pump Control Module A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U0109 means the engine controller no longer hears fuel pump control module A, the electronics that drive the in-tank pump at variable speed. GM's 2019 Corvette LT5 table watches frames $1EB and $4D9 and sets the code after 10 s as Type B over two trips. Ford instead returns the module status on a duty-cycle line: its 2020–2023 gasoline summary flags feedback stuck at 0 % or 100 %, the 2023 diesel summary a pump duty below 5 % or above 95 % for 0.5 s. Ford TSB 16-0060 (Super Duty 6.2/6.8 L, MIL) replaces the module; GM PIC5655A (Volt 2011–2013) points to a loose feed on circuit 1540 or its fuse in the rear fuse block. Pump B has U016C. Expect hard starts, stalling or no start.
- What you may notice
- MIL on
- Long cranking, stalling or no start
- Hesitation under load from low fuel pressure
- Likely causes
- LikelyLoose fuse, relay or feed terminal supplying the pump module
- PossibleFuel pump module internally faulty (common on some trucks, replaced by bulletin)
- PossibleCorroded connector or damaged wiring near the tank or frame
- RareEngine controller software setting the code falsely
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.