What does code U0044 mean?

Q: What does code U0044 mean?

Vehicle Communication Bus B (-) High. U0044 is a generic network communication code indicating that the vehicle's communication bus B negative circuit is reading a high voltage, which means the controller area network (CAN) data line is stuck at or near battery voltage instead of toggling between high and low states. The computer detected an abnormal voltage level on the bus B minus wire, which prevents modules from exchanging data reliably.

DTC codes / U00xx · Network wiring and bus faults / U0044

U0044Vehicle Communication Bus B (-) High

U0044 is a generic network communication code indicating that the vehicle's communication bus B negative circuit is reading a high voltage, which means the controller area network (CAN) data line is stuck at or near battery voltage instead of toggling between high and low states. The computer detected an abnormal voltage level on the bus B minus wire, which prevents modules from exchanging data reliably.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

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.