U0443 code meaning
Invalid Data Received From Body Control Module B
What U0443 means
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.
U0443 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0443
- Single comfort or lighting functions unavailable
- Code stored as history right after start-up without complaint
Common causes of U0443
- Most likelySoftware of module B or of the receiver sets the code without a real fault
- PossibleLoose connector or damaged network wiring at body control module B
- Less likelySupply or ground problem at body control module B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Body control module bCAN bus wiring
What each part of U0443 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 43 | The exact fault in that area. |
What to do next
- Note U0443 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 U0443
What does U0443 mean?
U0443 means "Invalid Data Received From Body Control Module B". U0443 is set when a receiver gets frames from body control module B but rejects their content. It is a generic code, so it means the same on every make.
Is it safe to drive with U0443?
U0443 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0443 fail an emissions test?
U0443 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 U0443 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. This is a job for a workshop.
Will U0443 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.