Network, generic

U025D Lost Communication With Front Controls Interface Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Front controls interface module B is a second switch panel at the front where the controls are split over two units. Ford uses this name (FCIMB): on 2023 Transit vans having SYNC 3 Lite and parking aid at the rear only, the parking aid disable switch sits in that panel, and vans built between 15 March and 2 June 2023 ignored it, since the park aid module carried a wrong configuration (SSM 51837). Mercedes fills the code differently: in its 8G-DCT transmission controller (724.1, models 118, 177 and 247) U025D00 means faulty communication with the head unit (LI27.00-P-077141). The module behind U025D therefore depends on the maker, and the description in the scan tool decides. A real loss disables the keys on the second panel or, at Mercedes, data from the head unit; panel A is U0256, corrupt data from B are U055E.

Likely causes

Second panel without power or ground, or connector loose after dashboard work
Head unit not on the bus where the maker maps U025D to it (Mercedes)
Wrong configuration of the panel or of the module that uses its switches
Internal failure of the second control panel

Symptoms

  • Switches on the second front panel without function
  • Functions that rely on head unit data unavailable (Mercedes)

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–900
Time0.2–2 h

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

Parts involved

front controls interface module bvehicle bus wiring

Related codes

U055EU0256U0257

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