U008A code meaning
Vehicle Communication Bus G Performance
What U008A means
U008A means Vehicle Communication Bus G still carries traffic, but not cleanly. No manufacturer documents U008A publicly. If Bus G is a CAN, every node counts its own transmit and receive errors; Wikipedia describes that a node turns error passive once a counter exceeds 127 and leaves the bus only after the transmit count passes 255, which is the bus-off case coded as U0079. U008A covers the range below that, with repeated frames, delays and occasional corrupted data. Signal quality is a frequent reason: Texas Instruments recommends unterminated stubs of no more than about 0.3 m on high-speed CAN, because reflections in longer branches, such as from tapped-in accessories, can distort bits at the sampling point. CARB requires communication errors to be detected alongside total loss.
U008A at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U008A
- Short dropouts of functions on Bus G
- Messages that appear briefly and vanish
Common causes of U008A
- Most likelyLoose or corroded contact in a Bus G connector
- PossibleAftermarket device tapped into Bus G with a long branch
- Less likelyTermination of Bus G missing or out of tolerance
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus g wiringModule connector
What each part of U008A means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 8A | The exact fault in that area. |
What to do next
- Note U008A 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 U008A
What does U008A mean?
U008A means "Vehicle Communication Bus G Performance". U008A means Vehicle Communication Bus G still carries traffic, but not cleanly. It is a generic code, so it means the same on every make.
Is it safe to drive with U008A?
U008A does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U008A fail an emissions test?
U008A 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 U008A to fix?
Difficulty: hard. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will U008A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.