What it means
A fault is detected on vehicle communication bus G. The code alone does not identify the cause or the functions affected.
How it works
Bus G is a vehicle communication network that carries messages among the modules assigned to it. This code reports a fault on bus G but does not specify a conductor or electrical condition, so diagnosis must establish whether wiring, a connected module, termination, or a gateway is disrupting communication.
Common causes
Most likely first.
- Damaged, loose, or corroded bus G wiring or connectors
- A control module disrupting bus communication
- Bus termination or gateway 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 for bus G communication codes and record freeze-frame data to identify which modules are missing and when the fault occurred.
- Check the vehicle network diagram to identify bus G's topology, connected modules, gateways, and termination points.
- Inspect accessible bus G wiring and connectors for looseness, corrosion, water intrusion, or physical damage.
- Use the manufacturer's network test procedure to check bus G communication and termination rather than assuming a particular wire or fault direction.
- If the wiring and termination pass, isolate connected modules as specified by the manufacturer to identify any module or gateway disrupting bus G.
Common fixes
- Reconnect or clean a loose or corroded bus G connector.
- Repair damaged bus G wiring or a poor splice.
- Restore a faulty bus G termination or gateway connection confirmed by testing.
- Repair or replace a confirmed module disrupting bus G communication.
Can I keep driving?
If the vehicle drives normally and only noncritical functions are affected, a short trip may be possible, but bus G features may be unavailable. Avoid driving if the affected network supports steering, braking, powertrain, or other safety-critical functions.
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.