What it means
A fault is detected on the negative conductor of vehicle communication bus F; the code descriptor specifies an open circuit. Which functions are affected depends on the vehicle’s network design.
How it works
Bus F carries messages among the modules connected to that network over positive and negative conductors. This code identifies an electrically open path on the bus F negative conductor, which can interrupt communication even when the positive path is intact.
Common causes
Most likely first.
- Open or damaged bus F negative wire
- Loose or corroded connector
- A module, gateway, or bus termination fault
Symptoms
- Communication faults in modules using bus F
- Warning lights or messages
- Functions relying on bus F may be unavailable
How to diagnose it
- Scan all modules for communication codes and save freeze-frame data to identify which bus F modules stopped responding.
- Use the vehicle network diagram to identify the bus F negative conductor and its connectors, gateways, and module connections.
- Inspect the negative wire and connectors for breaks, loose or backed-out pins, corrosion, and harness damage.
- With power isolated as directed by the manufacturer, test continuity of the negative conductor and check for unintended shorts to the positive conductor or ground.
- If the conductor passes, use the manufacturer's network procedure to check gateway connections, termination, and modules that may interrupt the path.
Common fixes
- Reconnect or clean a loose or corroded bus F negative connector.
- Repair an open or damaged section of the bus F negative wire.
- Repair a damaged terminal or connector on the negative path.
- Repair a confirmed gateway, termination, or module fault interrupting bus F.
Can I keep driving?
If only noncritical equipment is affected and the vehicle remains controllable, a short trip may be possible, but communication failures can disable connected functions. Avoid driving if bus F serves braking, steering, powertrain, or other safety-critical systems.
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.