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U0203 Lost Communication With Door Control Module E

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0203 reports a missing door control module E. For the 2011 Saab 9-5, GM fills this slot with the left rear door switch panel, so on these GM platforms E is the electronics behind the rear left window and lock switches rather than a fifth door. GM preliminary information PIT5606J (GMC Acadia and Cadillac XT5, 2017–2021) lists U0203 among a crowd of U-codes that show up together when the instrument panel harness rubs through at the steering column next to the intermediate shaft, or when water reaches the body control module through a blocked HVAC drain or enters connectors such as X200, X201 and X500. Door locks cycling while driving or seats moving by themselves belong to that picture. The code alone sets no MIL.

Likely causes

Instrument panel harness chafed at the steering column (GM Acadia/XT5)
Water at the body control module or in body connectors
Broken wires between rear door and body
Rear door switch panel module faulty

Symptoms

  • Left rear window or lock switches without function
  • Door locks cycle on their own while driving
  • Many other lost-communication codes stored at once

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–600
Time1–4 h

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

Parts involved

door module ecan bus

Related codes

U0202U0204U0504U0140

References: saabwisonline.com, static.nhtsa.gov.