Supercharger By-Pass System

Supercharger By-Pass (SCB) system allows high pressure air at outlet of supercharger to vent back to inlet side of supercharger. This equalizes pressure and eliminates boost for times when supercharger function is not required. Descriptions of supercharger by-pass system components are as follows:

1. Vacuum By-Pass Actuator
   
   During normal operation engine vacuum is applied to upper port of vacuum by-pass actuator. Lower port of vacuum by-pass actuator references air pressure in clean air tube, cancelling out any pressure difference in intake air system. Actuator opens during engine high vacuum conditions (by-passing supercharger). As throttle is opened and engine vacuum decreases, vacuum by-pass actuator closes to allow supercharger to pressurize air in intake manifold.
2. SCB Solenoid/Thermactor Air Control Solenoid
   
   SCB solenoid is used to control intake manifold vacuum to vacuum by-pass actuator. The SCB solenoid is de-energized during normal operating conditions. The Powertrain Control Module (PCM) will transmit an output signal to activate SCB solenoid to apply stored vacuum from vacuum reservoir assembly to vacuum by-pass actuator when an undesirable condition occurs in the engine. Once engine condition is corrected, SCB solenoid will be deactivated by PCM allowing engine intake manifold vacuum to control vacuum by-pass actuator.
3. Vacuum Reservoir Assembly
   
   Vacuum reservoir assembly stores vacuum that is applied to the vacuum actuator when a condition such as overheating or critical sensor failure is generated.