U0001high severityNetwork
High Speed CAN Communication Bus
on 1999 Ford F-250 5.4L V8 Triton · 4WD
What this code means
General malfunction on the high-speed CAN bus network.
Symptoms
- Multiple warning lights
- Communication errors
- Some systems inoperative
- Scan tool communication issues
Common causes
- CAN bus wiring damage
- Shorted CAN H or CAN L wire
- Missing termination resistor
- Module failure pulling down bus
- Aftermarket device interference
Diagnostic steps
- Check for aftermarket devices on OBD port
- Measure CAN bus resistance (should be ~60 ohms)
- Scope CAN H and CAN L signals
- Check for damaged wiring
- Isolate modules one at a time
Repair notes
CAN bus issues can be complex. Check wiring first. Remove aftermarket devices.
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Other Network codes on this vehicle
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
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