Pickup 4WD L4-2559cc 2.6L SOHC (4ZE1) (1988)
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Air Injection Vacuum Control Solenoid Valve: Description and Operation
AIR Vacuum Switching Valve
The vacuum switching valve (VSV) is an ECM controlled electric vacuum valve that directs control vacuum to the appropriate chamber of the air
injection system air switching valve. In its de-energized state, the VSV is open between the source vacuum port (Y) and control port (Z) while control
port (X) is vented to atmosphere. Vacuum is applied to the air switching valve and pump air is diverted to the air cleaner. When energized by the ECM,
the VSV opens the source vacuum port (Y) to control port (X) and vents control port (Z) to atmosphere. In this position, control vacuum applied to the
air switching valve directs pump air into the exhaust. The ECM operates the VSV during closed loop mode when the coolant temperature is less than 60
°C and for a programmed period of time after wide open throttle.
