General Information

Engine Control

P0444 Evaporative Emission System-Purge Control Valve Circuit Open - General Information

Component Location





General Description

The Evaporative Emission Control System (EVAP) prevents hydrocarbon (HC) vapors in the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The Purge Control Solenoid Valve (PCSV) is actuated (duty cycled) by the Powertrain Control Module (PCM) to control vapor flow from the canister to the intake manifold.

DTC Description

Checking output signals from PCSV every 10 sec. under detecting condition, if signals indicating open or short to ground in the circuit are detected for more than 5 sec, ECM sets P0444.

DTC Detecting Condition





Specification





Diagnostic Circuit Diagram





Signal Waveform & Data








Fig.1) Normal waveform of PCSV under 27% control condition.
Fig.2) Abnormal data of PCSV when PCSV circuit open.

The Purge Control Solenoid Valve (PCSV) is open or closed by ECM and vacuum of intake manifold.
At opening, fuel vapor from canister enters into intake manifold. To prevent vacuum from forming inside canister, ECM controls to open it. This photo shows the signal waveform of PCSV operating normally.