Circuit/System Testing
- With the ignition ON, the engine OFF, and the solenoid valve substituted with a test lamp, observe that the test lamp is not illuminated.
- If the test lamp is illuminated, test for a short to voltage on the solenoid voltage supply circuit or a faulty relay.
- Inspect the AIR pump inlet and outlet hoses/pipes for restrictions.
- Inspect the solenoid valve for leaks.