U008D code meaning
Vehicle Communication Bus G (+) High
What U008D means
U008D is stored when the (+) wire of Vehicle Communication Bus G carries excessive voltage, from a short to battery or another supply. No manufacturer documents U008D publicly. On a high-speed CAN this concerns CAN-High, and traffic often continues: NXP lists the fault among those that stay hidden unless a transceiver with bus diagnosis catches it, and onsemi saw frames still pass. The repair needs a second look, though. Texas Instruments warns that a bus wire in contact with a 24 V line drives the transceiver's short-circuit current through the terminating resistor and can burn out a 1/4 W part. After removing the short, measure the resistance between CAN-High and CAN-Low again; about 120 instead of 60 ohms means one terminator, often inside a module, has been damaged.
U008D 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 U008D
- Often no symptom, code found during a scan
- Sporadic dropouts on Bus G after a wiring fault
Common causes of U008D
- Most likely(+) wire of Bus G touching a battery or 24 V feed
- PossibleWater in a connector linking the bus to a supply pin
- Less likelyTerminating resistor damaged by an earlier short
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus g wiringCAN terminating resistor
What each part of U008D means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 8D | The exact fault in that area. |
What to do next
- Note U008D 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 U008D
What does U008D mean?
U008D means "Vehicle Communication Bus G (+) High". U008D is stored when the (+) wire of Vehicle Communication Bus G carries excessive voltage, from a short to battery or another supply. It is a generic code, so it means the same on every make.
Is it safe to drive with U008D?
U008D does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U008D fail an emissions test?
U008D 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 U008D to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U008D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.