What does code U0051 mean?

Q: What does code U0051 mean?

Vehicle Communication Bus C (-) Open. U0051 means the vehicle's communication network has lost the CAN C negative signal wire, so modules that rely on that bus can no longer exchange data. The computer detected an open circuit on the CAN C (-) line, which is the low-side half of a twisted pair used for high-speed communication between control modules.

DTC codes / U00xx · Network wiring and bus faults / U0051

U0051Vehicle Communication Bus C (-) Open

U0051 means the vehicle's communication network has lost the CAN C negative signal wire, so modules that rely on that bus can no longer exchange data. The computer detected an open circuit on the CAN C (-) line, which is the low-side half of a twisted pair used for high-speed communication between control modules.

SystemNetwork

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaNetwork wiring and bus faults

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.