The Evaporative Emissions Control (EVAP) system is designed to absorb fuel vapors, releasing them into the intake manifold during engine operation, where they mix with the air-fuel mixture. Key components include the fuel tank filler neck cap, EVAP canister, vapor pressure sensor, canister closed valve, two-way valve, and purge valve, with all but the purge valve located underneath the vehicle. When gasoline evaporates due to heat, it increases pressure in the sealed fuel tank, which is monitored by the vapor pressure sensor that informs the Powertrain Control Module (PCM). The vapors flow into the canister through a two-way valve and are purged into the intake manifold when the PCM activates the purge control solenoid valve. The canister purge control solenoid valve, located in the engine compartment, regulates vapor flow based on PCM commands to prevent a rich air-fuel mixture. During purging, atmospheric air is drawn into the canister to maintain pressure balance, with the canister closed valve controlling this process. The EVAP system diagnostic monitor checks for leaks by running a sequence that involves starting the engine and monitoring temperatures and pressures. If a leak is detected, the Malfunction Indicator Light (MIL) activates, and a Diagnostic Trouble Code (DTC) is stored. The PCM also monitors the canister closed valve and pressure switching valve to ensure proper operation, repeating the monitoring sequence as long as the engine is in closed loop. For replacement, the purge control solenoid valve requires disconnecting the negative battery terminal, removing the engine cover, and detaching the electrical connector and vacuum hoses before installation. Other components, such as the two-way valve, EVAP canister, vapor pressure sensor, and canister closed valve, also involve similar disconnection and reconnection procedures for replacement.
Posted by HyundaiPartsDeal Specialist 
