The SCB system allows the high pressure air at the outlet of the supercharger to vent back into the inlet of the supercharger, equalizing the pressure. This eliminates the boost (increased pressure that the supercharger produces) for times when supercharger function is undesirable. The system uses a vacuum bypass actuator, which controls the bypass valve inside the supercharger. The system normally operates with engine vacuum applied to the upper port of the vacuum bypass actuator, while the lower port references the air pressure in the clean air tube to cancel out any pressure difference in the intake air system. The actuator is set to open (bypassing the supercharger) during high vacuum engine conditions. As the throttle is opened and engine vacuum decreases, the actuator closes to allow the supercharger to pressurize the air in the manifold.
Removal & Installation
- Release the fuel system pressure.
- Disconnect the battery ground cable.
Remove the 4 nuts and the strut tower cross brace.
Rotate the drive belt tensioner clockwise and detach the drive belt from the supercharger pulley.
- Remove the Exhaust Gas Recirculation (EGR) system module. Remove the fuel rail.
- Disconnect the supercharger bubbler hose and the supercharger bypass vacuum actuator vacuum connector.
- Remove the 10 bolts and the supercharger.
- Remove and discard the supercharger gasket.
Cover the lower intake manifold with a shop towel to prevent foreign material from falling into the engine.
- Position the supercharger gasket on the lower intake manifold dowels.
- Position the supercharger and install the bolts.
- Tighten the bolts in the sequence shown in 2 stages:
- Connect the supercharger bubbler hose and the supercharger bypass vacuum actuator vacuum connector.
- Install the fuel rail.
- Install the EGR system module.
- Rotate the drive belt tensioner clockwise and attach the drive belt to the supercharger pulley.
- Install the strut tower cross brace and the 4 nuts, and tighten to 26 ft. lbs. (35 Nm)
- Connect the battery ground cable.
This pinpoint test is intended to diagnose the following:
Perform the following visual inspections. Repair or replace lines and hoses as required if a fault is present.
Verify that the Supercharger Bypass Actuator linkage moves when the engine is started, and that it returns to the original position when the supercharger bypass actuator vacuum line is disconnected.