U0008high severityNetwork
High Speed CAN Communication Bus (-) High
on 2001 Jeep Wrangler 4.0L I6 · 4WD
What this code means
The CAN Low wire voltage is higher than expected, indicating a short to power.
Symptoms
- CAN bus failure
- Multiple communication errors
- Systems unresponsive
Common causes
- CAN L shorted to battery voltage
- Wiring harness damage
- Module fault driving CAN L high
Diagnostic steps
- Measure CAN L voltage
- Disconnect modules to isolate
- Inspect wiring for shorts to power circuits
- Check harness routing near power wires
Repair notes
Repair CAN L short to power. Ensure CAN wiring is properly separated from power wiring.
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
U0006
High Speed CAN Communication Bus (-) Open
U0007
High Speed CAN Communication Bus (-) Low
U0009
High Speed CAN Communication Bus Shorted Together
U0010
Medium Speed CAN Communication Bus
U0028
Vehicle Communication Bus A Performance