U0003high severityNetwork
High Speed CAN Communication Bus (+) Open
on 2013 Audi A6 3.0L Supercharged V6 · AWD
What this code means
The CAN High wire is open, disrupting high-speed bus communication. CAN H carries the dominant high signal.
Symptoms
- Multiple modules offline
- Warning lights illuminated
- Systems inoperative
- No scan tool communication on some modules
Common causes
- Broken CAN H wire
- Corroded CAN H terminal
- Damaged CAN bus connector
- Wiring harness damage
Diagnostic steps
- Measure voltage on CAN H (should be ~2.5V idle, ~3.5V dominant)
- Check continuity of CAN H wire
- Inspect CAN bus connectors
- Locate break using voltage drop test
Repair notes
Locate and repair the open in the CAN H wire. Check all splice points.
Other Network codes on this vehicle
U0001
High Speed CAN Communication Bus
U0001
High Speed CAN Communication Bus
U0002
High Speed CAN Communication Bus Performance
U0002
High Speed CAN Communication Bus Performance
U0004
High Speed CAN Communication Bus (+) Low
U0004
High Speed CAN Communication Bus (+) Low
U0005
High Speed CAN Communication Bus (+) High
U0005
High Speed CAN Communication Bus (+) High
U0006
High Speed CAN Communication Bus (-) Open
U0006
High Speed CAN Communication Bus (-) Open