U0006high severityNetwork
High Speed CAN Communication Bus (-) Open
on 2011 BMW M3 E90 4.0L V8 S65 · RWD
What this code means
The CAN Low wire is open, disrupting high-speed CAN communication. CAN L carries the recessive low signal.
Symptoms
- Multiple modules lose communication
- Warning lights on
- Systems go offline intermittently
Common causes
- Broken CAN L wire
- Corroded CAN L terminal
- Connector damage
- Wiring harness break
Diagnostic steps
- Measure voltage on CAN L (should be ~2.5V idle, ~1.5V dominant)
- Check continuity of CAN L wire
- Inspect splice points and connectors
- Use scope to verify CAN L waveform
Repair notes
Locate and repair the open in the CAN L wire.
Other Network codes on this vehicle
U0001
High Speed CAN Communication Bus
U0002
High Speed CAN Communication Bus Performance
U0003
High Speed CAN Communication Bus (+) Open
U0004
High Speed CAN Communication Bus (+) Low
U0005
High Speed CAN Communication Bus (+) High
U0007
High Speed CAN Communication Bus (-) Low
U0008
High Speed CAN Communication Bus (-) High
U0009
High Speed CAN Communication Bus Shorted Together
U0010
Medium Speed CAN Communication Bus
U0028
Vehicle Communication Bus A Performance