P0445 Cadillac EVAP Purge Solenoid Circuit
– Evaporative Emission (EVAP) Purge Solenoid Control harness is open or shorted
– Evaporative Emission (EVAP) Purge Solenoid Control circuit poor electrical connection
The Evaporative Emission System (EVAP) Canister Purge Volume Control Solenoid Valve controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass passage 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 Engine Control Module (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.
The EVAP canister purge volume control solenoid valve uses a ON/OFF duty to control the flow rate of fuel vapor from the EVAP canister. 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.