U0001 High Speed CAN Communication Bus

Network Severity: High Generic OBD-II

A fault was detected on the high-speed CAN network.

Common causes

  • Damaged network wiring
  • Faulty module pulling the bus down
  • Low voltage
  • Water in connectors

Symptoms

  • Several warning lights at once
  • No start
  • Gauges not working

What to check

  1. Check battery voltage
  2. Measure CAN resistance
  3. Disconnect modules one at a time to find the culprit

Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for U0001, follow the service information for that make and model.