U008F code meaning
Vehicle Communication Bus G (-) Low
What U008F means
U008F is the low-voltage fault on the (-) wire of Vehicle Communication Bus G, which on a CAN means CAN-Low touching ground. No public manufacturer document uses U008F. On a high-speed CAN this is one of the faults that let messages through: onsemi measured working transmission with distorted levels, and the node drew about 72 instead of 65 mA because a terminating resistor now drains to ground. NXP lists CAN-Low to ground among the shorts its TJA1043 reports although traffic continues, and warns that such tolerated faults raise current draw and spoil electromagnetic compatibility. A car can therefore run normally with U008F stored. With the battery disconnected, a (-) wire showing near zero ohms to chassis confirms it.
U008F at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U008F
- Often no noticeable effect, code found during a scan
- Sporadic dropouts on Bus G
Common causes of U008F
- Most likely(-) wire chafed through to the body or a bracket
- PossibleMoisture in a connector bridging the (-) pin to a ground pin
- Less likelyDamaged transceiver in one module pulling the line down
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus g wiringCAN low wire
What each part of U008F means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 8F | The exact fault in that area. |
What to do next
- Note U008F 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 U008F
What does U008F mean?
U008F means "Vehicle Communication Bus G (-) Low". U008F is the low-voltage fault on the (-) wire of Vehicle Communication Bus G, which on a CAN means CAN-Low touching ground. It is a generic code, so it means the same on every make.
Is it safe to drive with U008F?
U008F does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U008F fail an emissions test?
U008F 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 U008F to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U008F clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.