What it means
A fault is detected on the negative conductor of vehicle communication bus G; the code descriptor specifies an open circuit. Which functions are affected depends on the vehicle’s network design.
How it works
Bus G's negative conductor works with its positive conductor to carry network messages between connected modules. U008E means the negative conductor is electrically open, so the network may lose communication across some or all of its connected modules.
Common causes
Most likely first.
- Open or damaged bus G negative wire
- Loose or corroded connector
- A module, gateway, or bus termination fault
Symptoms
- Communication faults in modules using bus G
- Warning lights or messages
- Functions relying on bus G may be unavailable
How to diagnose it
- Scan all modules and list which bus G units respond, which do not, and any related network codes to locate the likely open segment.
- Review freeze-frame or event data and live communication status for patterns such as failures after vibration or intermittent module loss.
- With the vehicle powered down as specified by the manufacturer, inspect bus G negative wiring and connectors for breaks, pulled pins, corrosion, or previous repairs.
- Check continuity along the bus G negative conductor and across each suspect connector using the manufacturer's procedure.
- If the conductor is intact, check bus G termination and isolate modules or the gateway as directed to find a connection or unit interrupting the line.
Common fixes
- Reconnect a loose bus G negative connector and clean corroded terminals.
- Repair a broken or damaged section of bus G negative wiring.
- Replace damaged connector terminals or correct an improper splice on the negative conductor.
- Repair a confirmed bus G termination, gateway, or module fault.
Can I keep driving?
Some vehicle functions may be unavailable if their modules depend on bus G. Drive only if essential systems operate normally, and stop if braking, steering, restraint, or other safety functions are affected.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.