IN−10 − INTRODUCTION GLOSSARY OF SAE AND LEXUS TERMS 15 TVV Thermal Vacuum Valve Bimetallic Vacuum Switching Valve (BVSV) Thermostatic Vacuum Switching Valve (TVSV) TWC Three−Way Catalytic Converter Three−Way Catalyst (TWC) CCRO TWC + OC Three−Way + Oxidation Catalytic Converter CCR + CC0 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