U0233 code meaning
Lost Communication With Side Obstacle Detection Control Module B
What U0233 means
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.
U0233 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0233
- Blind spot or cross traffic alert unavailable
- Sensor blocked message without any obstacle
Common causes of U0233
- Most likelySide radar software outdated
- PossibleDirt, snow or ice build-up behind the rear bumper
- PossibleCorroded radar connector or harness
- Less likelySide obstacle module B faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Blind spot module rightCAN bus wiring
What each part of U0233 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 33 | The exact fault in that area. |
What to do next
- Note U0233 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0233
What does U0233 mean?
U0233 means "Lost Communication With Side Obstacle Detection Control Module B". U0233 is stored when side obstacle detection control module B no longer reports. It is a generic code, so it means the same on every make.
Is it safe to drive with U0233?
U0233 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0233 fail an emissions test?
U0233 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U0233 to fix?
Difficulty: medium. A typical repair takes 0.3 to 3 hours of work. This is a job for a workshop.
Will U0233 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.