Network, generic

U0233 Lost Communication With Side Obstacle Detection Control Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0233 is stored when side obstacle detection control module B no longer reports. In the Saab 2011 list B is the right hand unit, which matches Volvo TJ 30858 (XC90, S90, 2016-2018): there the left sensor logs U023392 for the right one, and a software update is the fix. Toyota reverses the roles on the Tacoma 2016-2018 (T-SB-0063-19), where U0233 means the blind spot master is lost, listed alongside axis misalignment codes C1AC1/C1AC2. Ford TSB 24-2180 for Expedition and Navigator 2022-2024 sees U0233 and U0232 together in the IPMA with sensor blocked messages, blaming dirt build-up or corroded radar wiring. Because the two radars often talk to each other, a single cause can trigger both codes. Side warnings stop; no MIL.

Likely causes

Side radar software outdated
Dirt, snow or ice build-up behind the rear bumper
Corroded radar connector or harness
Side obstacle module B faulty

Symptoms

  • Blind spot or cross traffic alert unavailable
  • Sensor blocked message without any obstacle

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–900
Time0.3–3 h

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

Parts involved

blind spot module rightcan bus wiring

Related codes

U0232U0534U024F

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