What does code U041B mean?

Q: What does code U041B mean?

Invalid Data Received From Exhaust Gas Sensor Module A. U041B is a communication fault where the engine control module (ECM) or another controller expects valid data from the exhaust gas sensor module but receives missing, corrupted, or implausible messages over the controller area network (CAN) bus. The exhaust gas sensor module is a dedicated controller for the nitrogen oxide (NOx) and/or wideband oxygen sensors on many modern diesel and gasoline vehicles, and when its data is deemed invalid, the ECM sets this code and may illuminate the warning light.

DTC codes / U04xx · Invalid data received from a module / U041B

U041BInvalid Data Received From Exhaust Gas Sensor Module A

U041B is a communication fault where the engine control module (ECM) or another controller expects valid data from the exhaust gas sensor module but receives missing, corrupted, or implausible messages over the controller area network (CAN) bus. The exhaust gas sensor module is a dedicated controller for the nitrogen oxide (NOx) and/or wideband oxygen sensors on many modern diesel and gasoline vehicles, and when its data is deemed invalid, the ECM sets this code and may illuminate the warning light.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaInvalid data received from a module

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