Canister Purge Solenoid: Description and Operation

Duty Cycle EVAP Purge Solenoid Valve:

DESCRIPTION
The solenoid attaches to a bracket which is attached to the front engine mount. The solenoid will not operate properly unless it is installed with the electrical connector at the top.

OPERATION
The duty cycle EVAP purge 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.

When purging, the PCM energizes and de-energizes the solenoid approximately 5 or 10 times per second, depending upon operating conditions. The PCM varies the vapor flow rate by changing solenoid pulse width. Pulse width is the amount of time the solenoid energizes.

Duty Cycle EVAP Purge Solenoid:

DUTY CYCLE EVAP PURGE SOLENOID-PCM OUTPUT
The solenoid attaches to a bracket near the front engine mount. To operate correctly, the solenoid must be installed with the electrical connector on top.

The duty cycle EVAP purge solenoid regulates the rate of vapor flow from the EVAP canister to the throttle body. The powertrain control module 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 engine enters closed loop operation after it reaches a specified temperature and the programmed time delay ends. During closed loop operation, the PCM energizes and de-energizes the solenoid 5 to 10 times per second, depending upon operating conditions. The PCM varies the vapor flow rate by changing solenoid pulse width. Pulse width is the amount of time the solenoid is energized.