Possible Causes

Malfunction is detected when EVAP control system has a very large leak, or EVAP control system does not operate properly. Possible causes are:

• Incorrect fuel tank vacuum relief valve.
• Incorrect fuel filler cap.
• Fuel filler cap remains open or fails to close.
• Foreign matter caught in fuel filler cap.
• Leak in line between intake manifold and EVAP-CPVCSV.
• Foreign matter caught in EVAP Canister Vent Control Valve (EVAP-CVCV).
• EVAP canister or fuel tank leaks.
• Leak or blockage in EVAP purge line.
• Blockage in EVAP Control System Pressure Sensor (EVAP-CSPS) hose.
• Defective EVAP-CVCV or circuit.
• Defective EVAP-CPVCSV or circuit.
• Defective Fuel Tank Temperature (FTT) sensor.
• EVAP-CVCV "O" ring missing or damaged.
• Defective EVAP-CSPS.
• Defective refueling control valve.
• Leak in On-Board Refueling Vapor Recovery (ORVR) system.