OBD-II code · Network
U0011 Medium Speed CAN Communication Bus Performance
The medium-speed CAN bus is operating but with degraded performance — frame errors or excessive error counters. Comfort and infotainment functions may operate intermittently.
Is it safe to drive with U0011?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyCorrosion in body harness connectors
- PossibleOne module sending malformed frames
- Less likelyGateway module routing CAN messages incorrectly
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
- 1–5 h
- Emissions test
- Usually unaffected
- Parts involved
- Can Bus Wiring, Body Control Module
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.