What does code U0691 mean?

Q: What does code U0691 mean?

Lost Communication With Exhaust Pressure Sensor A. U0691 is a network communication code indicating that a control module on the vehicle's Controller Area Network (CAN) bus has lost contact with the exhaust pressure sensor designated as Sensor A. The module that monitors this sensor, typically the Powertrain Control Module (PCM) or a dedicated emissions control module, has stopped receiving valid data messages from the sensor over the communication network, which can affect emissions monitoring and engine management strategies.

DTC codes / U06xx · Network communication / U0691

U0691Lost Communication With Exhaust Pressure Sensor A

U0691 is a network communication code indicating that a control module on the vehicle's Controller Area Network (CAN) bus has lost contact with the exhaust pressure sensor designated as Sensor A. The module that monitors this sensor, typically the Powertrain Control Module (PCM) or a dedicated emissions control module, has stopped receiving valid data messages from the sensor over the communication network, which can affect emissions monitoring and engine management strategies.

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.