Technical information

Intake-Air System WL-C Engine
Variable Swirl Control Shutter Valves
• The BT-50 uses VSC shutter valves, which reduce the exhaust emissions at low engine
speeds. The operation is similar to that of the VSC shutter valves used on the Mazda6
pre F/L with 2.0 MZR-CD engine. The VSC shutter valves are located in the secondary
intake ports.
• The VSC shutter valves are operated from idle speed to 2,300 rpm.
Vacuum Chamber
• The vacuum chamber reduces vacuum fluctuations in the vacuum supply line for the
VBC and EGR solenoid valve.
BT-50_01025
1 To vacuum pump 3 Vacuum chamber
2 To VBC solenoid valve 4 To EGR solenoid valve
01-24 Service Training BT-50