Electric-Ported Vacuum Switch
Electric PVS is only used on some engines equipped with Air Injection System (AIS) and a catalytic converter. Two electric PVS valves are used, normally closed contacts and normally open contacts. On both types of valves the center and bottom ports operate in the same manner as a regular 3-port PVS. On normally closed contact valve, the contact is closed until coolant temperature reaches 235°F, at which time the contact opens. On the normally open contact valve, the contact is open until coolant temperature reaches 235°F, at which time the contact closes.