IN-8 INTRODUCTION — Abbreviations Used in This Manual ABBREVIATIONS USED IN THIS MANUAL Al Air Injection ASV Air Switching Valve BTDC Before Top Dead Center DP Dash Pot ECU Electronic Controlled Unit EFI Electronic Fuel Injection EGR Exhaust Gas Recirculation ESA Electronic Spark Advance EX Exhaust (manifold, valve) iG Ignition IN Intake (manifold, valve) ISC Idle Speed Control OHV Over Head Valve 0/S Oversize PCV Positive Crankcase Ventilation PS Power Steering SSM Special Service Materials SST Special Service Tools STD Standard SW Switch TCCS TOYOTA Computer Controlled System TDC Top Dead Center U/S Undersize VCV Vacuum Control Valve VSV Vacuum Switching Valve VTV Vacuum Transmitting Valve w/ With w/o Without