What does code U05A5 mean?

Q: What does code U05A5 mean?

Invalid Data Received From NH3 Sensor. U05A5 is a generic communication fault indicating that a control module received invalid or implausible data from the ammonia (NH3) sensor over the vehicle's controller area network (CAN) bus. The computer detected a message from the NH3 sensor that was missing, out of range, or failed its internal checksum, so it cannot trust the sensor's reading for emissions control.

DTC codes / U05xx · Network communication / U05A5

U05A5Invalid Data Received From NH3 Sensor

U05A5 is a generic communication fault indicating that a control module received invalid or implausible data from the ammonia (NH3) sensor over the vehicle's controller area network (CAN) bus. The computer detected a message from the NH3 sensor that was missing, out of range, or failed its internal checksum, so it cannot trust the sensor's reading for emissions control.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaNetwork communication

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