Diagnostic Method

Measure the pressure in the following procedures when the enable conditions are completed, and then diagnosis by calculating the result.

1. PMOF1 is equal to the intake manifold pressure at enable condition completed, and EGR target step is set to 50 steps (almost fully opened).
2. PMON is equal to the intake manifold pressure in 1 second after EGR target step is set 50 steps (when enable conditions are completed), and EGR target step is set to 0 step.
3. PMOF2 is equal to the intake manifold pressure in 1 second after EGR target step is set to 0 step (in 2 seconds after enable conditions are completed).
4. Calculate the judged value using the following formula.

Judged value = [PMON - (PMOF1 + PMOF2)/2]

Judged value < 18.63 mmHg, 2.48 kPa (18.63 mmHg, 0.733 inHg) --> NG

Judged value >= 2.48 kPa (18.63 mmHg, 0.733 inHg) --> OK

Time Needed for Diagnosis:  4 seconds

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

Fig 1: Malfunction Occurs In Continuous Driving Cycles Graph

Courtesy of SUBARU OF AMERICA, INC.