U0006high severityNetwork
High Speed CAN Communication Bus (-) Open
on 2014 Ram 2500 6.7L I6 Cummins Diesel · 4WD
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.
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
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
U0011
Control Module Communication Bus A Low