What does code U01B1 mean?

Q: What does code U01B1 mean?

Lost Communication With Particulate Matter Sensor B. U01B1 is a generic network communication code indicating that a control module on the vehicle's controller area network (CAN) bus has lost contact with the particulate matter sensor labeled B, which is typically the downstream sensor on a dual-sensor exhaust aftertreatment system. The module monitoring this sensor has stopped receiving valid messages from it for a calibrated period, so it sets this code and usually illuminates the malfunction indicator lamp.

DTC codes / U01xx · Lost communication with a control module / U01B1

U01B1Lost Communication With Particulate Matter Sensor B

U01B1 is a generic network communication code indicating that a control module on the vehicle's controller area network (CAN) bus has lost contact with the particulate matter sensor labeled B, which is typically the downstream sensor on a dual-sensor exhaust aftertreatment system. The module monitoring this sensor has stopped receiving valid messages from it for a calibrated period, so it sets this code and usually illuminates the malfunction indicator lamp.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaLost communication with a control 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.