Fuel Evaporative System: Prius

WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2002 Toyota Tundra, 2002 Toyota Tacoma, 2002 Toyota Sienna, 2002 Toyota Sequoia, and 2002 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

EVAP system prevents fuel tank gasoline vapors from escaping into the atmosphere. Fuel tank gasoline vapors are routed through EVAP canister, then into air cleaner and intake manifold for combustion in the cylinders. Vapor pressure sensor, purge flow switching valve Vacuum Switching Valve (VSV) and canister closed valve Vacuum Switching Valve (VSV) are used to determine if a leak or an abnormality exists in the EVAP system. See Figure. Engine Control Module (ECM) determines if a leak or an abnormality exists in EVAP system by using input signal from vapor pressure sensor. Vapor pressure sensor may also be referred to as EVAP vapor pressure sensor. Canister closed valve VSV may also be referred to as EVAP Canister Closed Valve Vacuum Switching Valve (EVAP-CCVVSV) or Canister Closed Valve Vacuum Switching Valve (CCV VSV). Purge flow switching valve VSV may also be referred to as EVAP Purge Flow Switching Valve Vacuum Switching Valve (EVAP-PFSVVSV). EVAP canister may also be referred to as charcoal canister. If a leak or an abnormality exists in EVAP system, a Diagnostic Trouble Code (DTC) will be stored in ECM. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieval of DTCs. EVAP Vacuum Switching Valve (VSV) is used to control EVAP system. ECM operates EVAP VSV which controls vacuum flow for EVAP operation. For EVAP system and component testing, see FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.