Possible Causes

Under normal conditions (non-closed throttle), sensor output voltage indicates if pressure drop and purge flow are adequate. If not, a malfunction is determined. Malfunction is detected when EVAP system has a leak or does not operate properly. Possible causes are:

• EVAP canister purge volume control solenoid valve stuck closed.
• Faulty EVAP control system pressure sensor and circuit.
• Loose, disconnected or improper connection of rubber tube.
• Blocked rubber hose.
• Cracked EVAP canister.
• Defective EVAP purge volume control solenoid valve circuit.
• Defective accelerator pedal position sensor.
• Blocked purge port.
• Defective EVAP canister vent control valve.