Network, generic

U025C Lost Communication With Special Purpose Vehicle Control Module D

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U025C is the last of the four lost-communication codes for special purpose controllers and covers unit D. No manufacturer documents it publicly, and none of the published systems names more than one such controller. GM's Universal Vehicle Module passes a subset of J1939 data to third-party devices; those devices read a separate output and are not members of the vehicle network, so their failure would not set a U025x code. Ford's Upfitter Integration System likewise feeds body equipment one way through J1939. A code for slot D therefore suggests a fourth add-on unit that sits directly on the vehicle bus, or a vehicle configuration that expects one. Verify first whether such a unit is fitted at all, then check its supply and bus connection. Driving is normally unaffected; corrupt data from D are U055D.

Likely causes

Vehicle configuration lists a fourth add-on unit that is not fitted or was removed
Unit D without power, ground or bus connection
Internal failure of controller D

Symptoms

  • Functions of the fourth conversion unit inoperative
  • Code stored without any noticeable complaint

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–700
Time0.3–3 h

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

Parts involved

special purpose vehicle module dvehicle bus wiring

Related codes

U055DU0259U025AU025B

References: gmupfitter.com, content.fordpro.com.