What it means
The vehicle bus reports loss of communication with engine sound control unit 2. Active sound design (interior synthetic engine sound or exterior pedestrian alert) for this channel stops.
How it works
Engine sound control unit 2 drives a separate channel of the vehicle's active sound system, which may provide cabin engine sound or an exterior pedestrian alert. U02A8 sets when the network stops receiving messages from unit 2, leaving that channel's sound function unavailable.
Common causes
Most likely first.
- Bus wiring open or shorted
- Module without power or ground
- Module failed
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Scan all modules and save freeze-frame data to see whether unit 2 lost communication alongside other devices or during a low-voltage event.
- Check active sound system status and live data to verify unit 2 is missing while unit 1 remains distinguishable in the scan results.
- Inspect unit 2's connector and harness for loose pins, corrosion, water entry, or damage.
- Check unit 2's power and ground using the manufacturer's wiring information and test conditions.
- Test the network circuit at unit 2 for an open, short, or poor connection according to the manufacturer's procedure.
- If its supplies and wiring pass, confirm failure of engine sound control unit 2 before replacing it.
Common fixes
- Reconnect or repair a loose or corroded unit 2 connector.
- Repair damaged network wiring to engine sound control unit 2.
- Restore unit 2's failed power or ground connection.
- Replace engine sound control unit 2 if its supplies and network circuit pass testing.
Can I keep driving?
The sound channel controlled by unit 2 may stop working, but this fault alone usually does not affect propulsion. If that channel provides an exterior pedestrian alert, take extra care around pedestrians until it is restored.
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.