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P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE EC-301 < DTC/CIRCUIT DIAGNOSIS > [VK56DE] C D E F G H I J K L M A EC N P O P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID Description INFOID:0000000009886707 SYSTEM DESCRIPTION *1: ECM determines the start signal status by the signals of engine speed and battery voltage. This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas- sage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor from the EVAP canister is regulated as the air flow changes. COMPONENT DESCRIPTION The EVAP canister purge volume control solenoid valve uses a ON/ OFF duty to control the flow rate of fuel vapor from the EVAP canis- ter. The EVAP canister purge volume control solenoid valve is moved by ON/OFF pulses from the ECM. The longer the ON pulse, the greater the amount of fuel vapor that will flow through the valve. On Board Diagnosis Logic INFOID:0000000009886708 Sensor Input signal to ECM ECM function Actuator Crankshaft position sensor (POS) Engine speed* 1 EVAP canister EVAP canister purge vol- Mass air flow sensor Amount of intake air Engine coolant temperature sensor Engine coolant temperature Battery Battery voltage* 1 Throttle position sensor Throttle position Accelerator pedal position sensor Accelerator pedal position Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas Fuel tank temperature sensor Fuel temperature in fuel tank Wheel sensor Vehicle speed* 2 PBIB2057E DTC No. Trouble diagnosis name DTC detecting condition Possible cause P0444 EVAP canister purge volume An excessively low voltage signal is sent • Harness or connectors (The solenoid valve circuit is open or • EVAP canister purge volume control so- lenoid valve P0445 EVAP canister purge volume An excessively high voltage signal is sent • Harness or connectors (The solenoid valve circuit is shorted.) • EVAP canister purge volume control so- lenoid valve |