Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Vapor Pressure Sensor (Prius)
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 Fig 1. EVAP system may also be referred to as fuel evaporative system. Engine Control Module (ECM) determines if a leak or an abnormality exists in EVAP system by using input signal from vapor pressure sensor. If a leak or abnormality exists, a Diagnostic Trouble Code (DTC) will be stored in the ECM. 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.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.