What does code P04A4 mean?

Q: What does code P04A4 mean?

Exhaust Pressure Control Valve B Stuck Open. P04A4 indicates the powertrain control module has detected that the exhaust pressure control valve B is stuck in the open position, meaning the valve is not closing when commanded. The computer typically compares the expected valve position or the resulting exhaust pressure change against what it actually sees, and flags the code when the valve fails to move to the closed position.

DTC codes / P04xx · Auxiliary emission controls / P04A4

P04A4Exhaust Pressure Control Valve B Stuck Open

P04A4 indicates the powertrain control module has detected that the exhaust pressure control valve B is stuck in the open position, meaning the valve is not closing when commanded. The computer typically compares the expected valve position or the resulting exhaust pressure change against what it actually sees, and flags the code when the valve fails to move to the closed position.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

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