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EVAPORATIVE EMISSION CONTROLS INDEX page page DESCRIPTION AND OPERATION EVAP CANISTER . . . . . . . . . . . . . . . . . . . . . . . . 13 SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 PROPORTIONAL PURGE SOLENOID—PCM OUTPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 ROLLOVER VALVE . . . . . . . . . . . . . . . . . . . . . . . 13 LABEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 DIAGNOSIS AND TESTING LEAK DETECTION PUMP . . . . . . . . . . . . . . . . . 15 REMOVAL AND INSTALLATION EVAP CANISTER . . . . . . . . . . . . . . . . . . . . . . . . 15 DESCRIPTION AND OPERATION EVAPORATION CONTROL SYSTEM The evaporation control system prevents the emis- sion of fuel tank vapors into the atmosphere. When All engines use a proportional purge system. The PCM controls vapor flow by operating the purge sole- NOTE: The evaporative system uses specially man- NOTE: For more information on Onboard Refueling ROLLOVER VALVE The LH fuel tank has fuel and vapor controls that allow the vehicle to pass a full 360° rollover without EVAP CANISTER All vehicles use a, maintenance free, evaporative (EVAP) canister. Fuel tank vapors vent into the can- until intake manifold vacuum draws them into the The canister protrudes through the top of the bracket. The vacuum and vapor tubes connect to the PROPORTIONAL PURGE SOLENOID—PCM All vehicles use a proportional purge solenoid. The solenoid regulates the rate of vapor flow from the During the cold start warm-up period and the hot start time delay, the PCM does not energize the sole- The proportional purge solenoid operates at a fre- quency of 200 hz and is controlled by an engine con- POSITIVE CRANKCASE VENTILATION (PCV) Intake manifold vacuum removes crankcase vapors and piston blow-by from the engine. Emissions pass 300M EMISSION CONTROL SYSTEMS 25 - 13 |