U0003
High Speed CAN Communication Bus (+) Open
U0003 is an OBD-II diagnostic trouble code meaning: High Speed CAN Communication Bus (+) Open. Common causes: broken wire in the can bus (+), corrosion of contacts in connectors. Estimated repair cost: $6–56.
Symptoms
- Check Engine light comes on
- Incorrect operation of various vehicle systems
- Lost connection with some modules
- Problems starting the engine
- Dashboard malfunctions
Causes
- Broken wire in the CAN bus (+)
- Corrosion of contacts in connectors
- Wiring harness damage
- Fault in one of the modules connected to the bus
- Problems with CAN bus power supply
How to Fix
- Check the integrity of the CAN bus wires (+)
- Inspect connectors for corrosion or damage
- Check resistance and continuity
- Diagnose the operation of modules connected to the bus
- If necessary, replace damaged wires or connectors
Related codes
Error U0003 by Vehicle Brand
FAQ
What does the U0003 code mean?
U0003 is an OBD-II diagnostic trouble code that indicates: High Speed CAN Communication Bus (+) Open
What causes a U0003 error code?
The most common causes of U0003 include: Broken wire in the CAN bus (+); Corrosion of contacts in connectors; Wiring harness damage; Fault in one of the modules connected to the bus.
How do I fix a U0003 diagnostic trouble code?
To fix U0003: Check the integrity of the CAN bus wires (+). Inspect connectors for corrosion or damage. Check resistance and continuity. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U0003?
Do not drive — repair immediately
How much does it cost to fix U0003?
The estimated repair cost for U0003 is $6–56. Actual cost depends on your vehicle, location, and labor rates.
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