Network, generic

U0278 Lost Communication With Seat Control Module L

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Seat control module L is the right-hand partner of K. On the 2025 Lincoln Navigator, Ford's SCML runs the second-row power seat on the passenger side; release SCML-25.5.5.3 targeted its memory function, and SSM 54226 lists it as the rear right-hand power seat module, with its own configuration app that must be run after a module change, for example when the seat ignores its fore-aft switch. U0278 signals that SCML has dropped off the network entirely, which no public bulletin covers for this code. Under-seat harnesses on sliding second-row seats are flexed with every adjustment, so connectors and wiring there deserve the first look. Only the right second-row seat loses its electrical functions.

Likely causes

Harness under the sliding seat damaged by seat movement
SCML configuration missing after replacement or update
Power or ground to SCML interrupted
Seat control module L internally faulty

Symptoms

  • Right second-row power seat inoperative
  • Seat memory on that seat not working

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–800
Time0.3–2.5 h

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

Parts involved

seat control module lvehicle bus wiring

Related codes

U0277U0579U024CU0209

References: static.nhtsa.gov, static.nhtsa.gov.