Network, generic

U0443 Invalid Data Received From Body Control Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0443 is set when a receiver gets frames from body control module B but rejects their content. The letters B to E come into play when a vehicle spreads body electronics such as lighting, locks, wipers or power distribution over several controllers; module A has U0431, a single BCM U0422, and lost contact with B is U0142. No car maker explains publicly which unit carries the letter B. Harley-Davidson uses the code on motorcycles: bulletin M1619 reports U04438F (failure type 8F, erratic) stored by the left hand control module shortly after start-up, alongside U04318F in the right hand module. As history entries they need no repair and await new software; if they are current, normal diagnosis applies. In cars, invalid data from module B tends to disable single comfort functions or trigger warnings.

Likely causes

Software of module B or of the receiver sets the code without a real fault
Loose connector or damaged network wiring at body control module B
Supply or ground problem at body control module B

Symptoms

  • Single comfort or lighting functions unavailable
  • Code stored as history right after start-up without complaint

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–600
Time0.3–2 h

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

Parts involved

body control module bcan bus wiring

Related codes

U0142U0431U0444U0422

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