U008B code meaning
Vehicle Communication Bus G (+) Open
What U008B means
On Vehicle Communication Bus G, U008B flags an open (+) conductor, which on a CAN means CAN-High. No manufacturer documents U008B publicly. A useful clue comes from the termination: Texas Instruments describes a high-speed CAN line ending in a 120-ohm resistor at each end, which a meter across CAN-High and CAN-Low sees as about 60 ohms. With CAN-High broken, only the resistor on the measuring side remains in the loop and the reading rises to roughly 120 ohms; on the other side of the break it is the same, which helps locate the gap. Meanwhile the far nodes miss part of the signal and fall silent or drop frames, and as NXP notes, transceivers do not report open lines themselves. Check the (+) wire through every connector of Bus G.
U008B 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 U008B
- Some modules on Bus G not reachable with a scan tool
- Intermittent faults that change with temperature or movement
Common causes of U008B
- Most likely(+) wire of Bus G broken at a hinge, seat or door passage
- PossibleTerminal of the (+) wire pushed out of its connector cavity
- Less likelyCorroded splice in the (+) wire
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 U008B means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 8B | The exact fault in that area. |
What to do next
- Note U008B 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 U008B
What does U008B mean?
U008B means "Vehicle Communication Bus G (+) Open". On Vehicle Communication Bus G, U008B flags an open (+) conductor, which on a CAN means CAN-High. It is a generic code, so it means the same on every make.
Is it safe to drive with U008B?
U008B does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U008B fail an emissions test?
U008B 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 U008B to fix?
Difficulty: hard. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will U008B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.