U0010 U0xxx · Network (U) Medium severity
Medium Speed CAN Communication Bus
The medium-speed CAN bus (typically body/comfort functions) is down. Drivability usually survives, but body functions drop out.
Severity guidance: Medium — drivability or emissions affected, book it in this week
Symptoms you will notice
- Window, lock or lighting faults
- Multiple body modules unreachable
- Instrument cluster warnings
Common causes
Ordered from most to least likely — start at the top.
- 1 Short or open in the body bus wiring
- 2 Failed body module dragging the line
- 3 Water ingress
- 4 Faulty gateway
How to diagnose it
Cheapest and least invasive first — most of these codes are not a parts problem.
- ✓ Identify which functions share the bus — that tells you where to look.
- ✓ Measure bus voltages and resistance as with the high-speed bus.
- ✓ Isolate modules one at a time.
- ✓ Check the gateway module, which links body and powertrain buses.
Repair options
- Repair the bus wiring
- Replace the offending module
- Repair or replace the gateway
U0010 — frequently asked questions
The engine is fine but nothing else works — why? +
Separate buses. The powertrain CAN still runs while the body bus is down.
What does the gateway do? +
It translates and routes messages between buses. A gateway fault looks like many unrelated module faults.
Confirm the diagnosis before you buy parts
Send us the code, freeze-frame data and the vehicle — our engineers will tell you what to test first.