System Testing: Federal
- Check condition of all hoses and tubes. Remove air suction hose from air switching valve. Verify bubbling noise is heard from air switching valve at idle.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Disconnect vacuum hose from air switching valve. Bubbling noise should not be heard from air switching valve at idle. Reconnect vacuum and air suction hoses.
- To check vacuum control valve, race engine and quickly close throttle valve. Bubbling noise should stop momentarily. If system does not operate as outlined, check each component. See COMPONENT TESTS.