Diagnostic method

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

• Abnormality Judgment 

If OK judgment cannot be made, extend Mode Z, and Judge as NG when the following conditions are established after predetermined amount of time.

Judgment Value 

Time Needed for Diagnosis:  5000 ms + 3000 ms + 13000 ms

Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.

When judgment for purge control solenoid valve stuck open NG is made, end the evaporative diagnosis. Cancel the evaporative diagnosis when the OK/NG judgment for purge control solenoid valve stuck open cannot be made in Mode Z.

• Normality Judgment 

Judge as OK and change to Mode A when the following conditions are established after 3000 ms has passed since Mode Z started.

Judgment Value 

Normal 

Fig 1: Fuel Tank Pressure Graph

Courtesy of SUBARU OF AMERICA, INC.

evptez - evptezha < 0.4 kPa (3 mmHg, 0.1 inHg) Normal when above is established

Time Needed for Diagnosis:  5000 ms + 3000 ms