Code Definition

P0447 — Evaporative Emission Control System Vent Control Circuit Open

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0447

P0447 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0447 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0447 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The engine control module (ECM) sets this code when it detects an open circuit in the EVAP vent control valve circuit. The vent control valve allows fresh air to enter the EVAP system and closes during leak tests. An open circuit prevents the ECM from properly controlling the valve, which can affect EVAP system operation and emissions performance.

Quick Facts