Checking Function

1. Engine oil temperature 50°C (122°F) minimum.
2. Start engine and let idle.

   EGR valve diaphragm rod is pulled toward vacuum hose connector.

   Diaphragm rod visible through opening on back side of diaphragm means exhaust gas is being supplied.

3. Slowly increase engine speed, when engine speed exceeds 1200 RPM, EGR is interrupted for 2 seconds.

   Diaphragm rod moves toward intake manifold for 2 seconds then moves back toward vacuum connection.

4. Continue to raise engine speed until part throttle switch closes.

   Diaphragm rod moves back toward intake manifold means EGR is interrupted.

If EGR does not work as described, go to Checking Activation .