Full Size Buick FWD V6-181 3.0L (1984)
Vacuum Advance Control Solenoid: Description and Operation
This valve is used on some automatic transmission equipped vehicles with air conditioning. The function of the DVSV is to prevent detonation when
the A/C is on and coolant temperature is above 120° F, by supplying ported vacuum rather than manifold vacuum to the distributor vacuum advance unit.
The solenoid is energized whenever the air conditioning is in use.