U0484 code meaning
Invalid Data Received From Lighting Control Module - Rear A
What U0484 means
U0484 is set when frames from rear lighting control module A are received but carry values the listener cannot accept; U0183 stands for lost contact, while rear module B has U0252 and U0553. Such modules drive tail, stop and turn lamps or LED segments at the back and report their status. BMW's 2022 iX shows the layout: four rear light modules, two in the side panels and two in the tailgate, share Body_CAN, and a software error in them produced communication and time-out entries with rear light warnings although the lamps worked (SIB 63 06 22). GM updated the exterior lighting module of 2024 Corvettes that failed to tell the driver about a failed rear turn signal, an indication FMVSS 108 requires. No maker documents U0484 itself. Lamp warnings, possible default lighting; no MIL.
U0484 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0484
- Rear light system warning although the lamps may still work
- Turn, stop or tail lamp failures not reported or lamps in default mode
Common causes of U0484
- Most likelySoftware error in the rear lighting module or a module not updated to the current level
- PossibleChafed or broken wires in the tailgate or trunk lid harness
- Less likelyWater ingress at a rear lamp connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Rear lighting module a
What each part of U0484 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 84 | The exact fault in that area. |
What to do next
- Note U0484 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 U0484
What does U0484 mean?
U0484 means "Invalid Data Received From Lighting Control Module - Rear A". U0484 is set when frames from rear lighting control module A are received but carry values the listener cannot accept; U0183 stands for lost contact, while rear module B has U0252 and U0553. It is a generic code, so it means the same on every make.
Is it safe to drive with U0484?
U0484 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0484 fail an emissions test?
U0484 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 U0484 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2.5 hours of work. This is a job for a workshop.
Will U0484 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.