High Speed CAN Communication Bus (-) Open
2016-2016 Subaru Forester 2.5L H4
The 2016 Subaru Forester is equipped with a 2.5L flat-4 engine. Below you'll find detailed u0006 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
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.
Related Codes
Other Network Codes
- U0001High Speed CAN Communication Bus
- U0002High Speed CAN Communication Bus Performance
- U0003High Speed CAN Communication Bus (+) Open
- U0004High Speed CAN Communication Bus (+) Low
- U0005High Speed CAN Communication Bus (+) High
- U0007High Speed CAN Communication Bus (-) Low
- U0008High Speed CAN Communication Bus (-) High
- U0009High Speed CAN Communication Bus Shorted Together
- U0010Medium Speed CAN Communication Bus
- U0028Vehicle Communication Bus A Performance
U0006 on Other Vehicles
Common Questions
What does code U0006 mean on a 2016-2016 Subaru Forester?
U0006 stands for "High Speed CAN Communication Bus (-) Open". The CAN Low wire is open, disrupting high-speed CAN communication. CAN L carries the recessive low signal.
What are the symptoms of U0006 on a Subaru Forester?
Common symptoms of U0006 include: Multiple modules lose communication, Warning lights on, Systems go offline intermittently.
What causes U0006 on a 2016-2016 Subaru Forester?
Common causes of U0006 include: Broken CAN L wire, Corroded CAN L terminal, Connector damage, Wiring harness break.
Last updated: March 2026