Wagoneer L6-258 4.2L VIN C 2-bbl (1982)
Upstream Solenoid: Description and Operation
OPERATION
The upstream solenoid, located on the rear of the cylinder head cover, controls the air control valve circuit. The solenoid is grounded through the
Computerized Emission Control (CEC) system.
When the solenoid is energized, it opens the air control valve vacuum to the atmosphere and the air control valve directs system pressure
upstream" to the exhaust manifold.
When the solenoid is deenergized, vacuum passes through it and to the air control valve, directing air system pressure downstream" to the rear half
of the dual bed catalytic converter.
