Ok, there's a lot of really smart people on this forum, so I'm hoping someone can help me figure this one out.

The Acoustic Control Induction System (ACIS) changes the length of the intake manifold based on engine rpm and load to increase engine performance under heavy load and above 2700rpm. It does this with two vacuum actuated butterfly valves one located in the throttle body and the other in the intake manifold. Each valve is driven by a vacuum motor connected to a solenoid activated vacuum switch.

My question is this. There are two valves/solenoids but I can find only one control signal from the ECU (called ACIS). Obviously these valves need to be controlled independently so

1) which one is connected to the ACIS terminal on the ECU?
2) what signal drives the other one?.

Thanks in advance.
Baetke

 

Hi Baetke;
The vsv solenoid on the front left in your picture is for the ACIS. The vsv solenoid on the front right is for the EGR valve. The one toward the rear is the vsv solenoid for the EVAP system. The ACIS signal goes through the intake air control valve.