IN–41 INTRODUCTION – GLOSSARY OF SAE AND TOYOTA TERMS TVV Thermal Vacuum Valve Bimetallic Vacuum Switching Valve (BVSV) Thermostatic Vacuum Switching Valve (TVSV) TWC Three–Way Catalytic Converter Three–Way Catalytic (TWC) CCRO TWC+OC Three–Way + Oxidation Catalytic Converter CCR + CCo VAF Volume Air Flow Air Flow Meter VR Voltage Regulator Voltage Regulator VSS Vehicle Speed Sensor Vehicle Speed Sensor (Read Switch Type) WOT Wide Open Throttle Full Throttle WU–OC Warm Up Oxidation Catalytic Converter – WU–TWC Warm Up Three–Way Catalytic Converter Manifold Converter 3GR Third Gear – 4GR Fourth Gear –