Circuit Description

Vapor pressure sensor, canister closed valve Vacuum Switching Valve (VSV) and pressure switching valve VSV are used to detect faults in EVAP system. The ECM decides whether there is an abnormality in the evaporative emission control system based on the vapor pressure sensor signal. Possible causes are:

• Open or short in vapor pressor sensor circuit.
• Faulty vapor pressure sensor.
• Faulty ECM.