OBD-II code · Network
U0002 High Speed CAN Communication Bus Performance
The high-speed CAN bus is functional but performance is degraded — frame errors, bit errors or excessive bus load have been detected. Communication may be intermittent rather than completely lost, leading to sporadic warning lamps.
Is it safe to drive with U0002?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyCorrosion or poor contact in CAN connectors
- PossibleElectromagnetic interference (aftermarket electronics)
- PossibleOne module sending malformed frames
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–6 h
- Emissions test
- Usually unaffected
- Parts involved
- Can Bus Wiring, Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.