Network, generic

U020B Lost Communication With Door Control Module H

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U020B is the last of the eight door module slots and flags lost contact with door control module H. No manufacturer documents this code publicly, and on ordinary four-door cars the letter stays empty. Where it is assigned, the receiving unit, usually body control module or gateway, misses the cyclic messages of that door unit; the body control module itself keeps locking and lighting alive, so only functions local to that door fail. A loose plug between door and body is the best first suspect: Volkswagen tech tip 97-21-02 links door module dropouts with U019900 or U020000 to poorly seated pins at the A-pillar; that check suits any door unit. U050C is invalid data. No MIL.

Likely causes

Poorly seated or corroded pins in the door-to-body connector
Wire break in the door transition
Door module H faulty

Symptoms

  • Window, lock or switches of one door inoperative
  • Door ajar or door system warning in the cluster

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–600
Time0.5–3 h

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

Parts involved

door module hcan bus

Related codes

U0205U0199U050CU0140

References: static.nhtsa.gov, en.wikipedia.org.