Signal Wave From

Fig 1: DTC P0444 Signal Wave Form

Courtesy of KIA MOTORS AMERICA, INC.

During normal operation, the PCSV opens and closes, depending on throttle angle and intake manifold vacuum. When it opens, fuel vapors are flushed from the canister and drawn into the intake manifold. To avoid a vacuum build-up in the canister, the canister close valve is normally held open to allow fresh air to replace the vapors drawn into the intake manifold. The given data is the signal waveform when the PCSV operates normally. Note that the PCSV will not operate until the engine has reached normal operating temperature.