Canister Purge Solenoid: Description and Operation

Fig. 110 Purge And Switchover Valve Locations:

The CIS-E control unit controls charcoal canister regeneration via the purge switchover valve. The switchover valve replaces the thermo vacuum valve on former models.
At coolant temperatures above 175°F and with the idle speed contact of the throttle switch open the CIS-E control unit signals the switchover valve to connect vacuum from the intake manifold to the purge valve. The purge valve then opens allowing fuel vapor from the charcoal canister to be drawn into the intake manifold via a port in the throttle housing. At coolant temperatures greater than 212°F or intake temperatures greater than 130°F, and a vehicle speed of less than 3 mph purging takes place even with the idle contact closed.