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U0109 Lost Communication With Fuel Pump Control Module A

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Loose fuse, relay or feed terminal supplying the pump module
Fuel pump module internally faulty (common on some trucks, replaced by bulletin)
Corroded connector or damaged wiring near the tank or frame
Engine controller software setting the code falsely

Symptoms

  • MIL on
  • Long cranking, stalling or no start
  • Hesitation under load from low fuel pressure

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–700
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel pump control modulecan bus wiring

Related codes

U016CU0310U0410P0627P025A

References: gsi.ext.gm.com, fordservicecontent.com, fordservicecontent.com, static.nhtsa.gov.