Evaporative Emission Purge Solenoid
Description & Operation
The evaporation control system prevents the emission of fuel tank vapors into the atmosphere. When fuel evaporates in the fuel tank, the vapors pass through vent hoses or tubes to an activated carbon filled evaporative canister. The canister temporarily holds the vapors. The Powertrain Control Module (PCM) allows intake manifold vacuum to draw vapors into the combustion chambers during certain operating conditions. All engines use a proportional purge solenoid system. The PCM controls vapor flow by operating the purge solenoid. Refer to Proportional Purge Solenoid in this section.
Proportion Purge Solenoid Valve
All vehicles use a proportional purge solenoid. The solenoid regulates the rate of vapor flow from the EVAP canister to the throttle body. The PCM operates the solenoid.
During the cold start warm-up period and the hot start time delay, the PCM does not energize the solenoid. When de-energized, no vapors are purged.
The proportional purge solenoid operates at a frequency of 200 hz and is controlled by an engine controller circuit that senses the current being applied to the proportional purge solenoid and then adjusts that current to achieve the desired purge flow. The proportional purge solenoid controls the purge rate of fuel vapors from the vapor canister and fuel tank to the engine intake manifold.Removal & Installation
The solenoid attaches to a bracket near the radiator on the passenger side of vehicle. The solenoid will not operate unless it is installed correctly.
- Disconnect electrical connector from solenoid.
- Disconnect vacuum tubes from solenoid.
- Remove solenoid from bracket.
- The top of the solenoid has TOP printed on it. The solenoid will not operate unless it is installed correctly.
- Install solenoid on bracket.
- Connect vacuum tube to solenoid.
- Connect electrical connector to solenoid.