OBD-II code · Network
U0001 High Speed CAN Communication Bus
A general fault on the high-speed CAN bus has been detected. This bus typically connects powertrain modules (ECM, TCM, ABS) at 500 kbit/s and a fault disables communication between them, often triggering multiple secondary DTCs in other modules.
Is it safe to drive with U0001?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyCAN-High and CAN-Low shorted together
- Most likelyOpen circuit in CAN bus wiring
- PossibleTerminating resistor failed (not 60 ohms across bus)
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Can Bus Wiring, Can Terminating Resistor, Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.