OBD fault code library

Look up any P or U code to see what it means, what causes it, the parts involved and how it gets fixed.

Free on OBD DashX

Looking for real-world repair data?

OBD DashX shows which problems come with each code, how often they show up in other vehicles, and how to fix them — step by step.

  • Real-world fix data
  • How often it happens
  • Step-by-step repairs
Browse codes on OBD DashX No sign-up needed · available in 10 languages
U1661 /codes/dtcs/u1661
Communication Network System
U1662 /codes/dtcs/u1662
Communication Network System
U1663 /codes/dtcs/u1663
Communication Network System
U1664 /codes/dtcs/u1664
Communication Network System
U1665 /codes/dtcs/u1665
Communication Network System
U1666 /codes/dtcs/u1666
Communication Network System
U1668 /codes/dtcs/u1668
Communication Network System
U1669 /codes/dtcs/u1669
Communication Network System
U166A /codes/dtcs/u166a
Communication Network System
U166B /codes/dtcs/u166b
Communication Network System
U166C /codes/dtcs/u166c
Communication Network System
U166D /codes/dtcs/u166d
Communication Network System
U166F /codes/dtcs/u166f
Communication Network System
U1671 /codes/dtcs/u1671
Communication Network System
U1672 /codes/dtcs/u1672
Communication Network System

Search fault codes

Scan your own car

Read and clear fault codes, live data and service resets with the CaRPM app.