Diagnostic Method: Notes

0.04-inch Diagnosis

Mode Z: (Purge control solenoid valve opening failure diagnosis)

When performing the leakage diagnosis of the EVAP system, the purge control solenoid valve must operate properly. Therefore, mode Z is used to diagnose a stuck open condition of the purge control solenoid valve by monitoring the tank pressure.

Note that if a purge control solenoid valve stuck open fault is detected, the EVAP system leakage diagnosis is cancelled.

Purge Control Solenoid Valve Stuck Open Diagnosis

DTC

P0457 Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off)

Diagnostic method

Purge control solenoid valve stuck open diagnosis is performed in mode Z as shown in the figure below.

Fig 1: Diagnostic Method For Purge Control Solenoid Valve Stuck Open

Courtesy of SUBARU OF AMERICA, INC.

Purge Control Solenoid Valve Function Diagnosis

DTC

P0457 Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off)

Purge control solenoid valve functional diagnosis is performed by monitoring the tank pressure in mode Z.