2007 Liberty KJ Factory Service Manual 25 - EMISSIONS CONTROL

SOLENOID-EVAP/PURGE

DESCRIPTION



The duty cycle EVAP canister purge solenoid (DCP) (2) is located in the engine compartment. It is attached to a bracket located between the battery and the Power Distribution Center (PDC). The EVAP system test port is located near the solenoid.

OPERATION

The duty cycle EVAP canister purge solenoid (DCP) regulates the rate of vapor flow from the EVAP canister to the intake manifold. The Powertrain Control Module (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 PCM de-energizes the solenoid during open loop operation.

The engine enters closed loop operation after it reaches a specified temperature and the time delay ends. During closed loop operation, the PCM cycles (energizes and de-energizes) the solenoid 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 that the solenoid is energized. The PCM adjusts solenoid pulse width based on engine operating condition.

REMOVAL



The duty cycle EVAP canister purge solenoid (DCP) (2) is located in the engine compartment. It is attached to a bracket located between the battery and the Power Distribution Center (PDC). The EVAP system test port is located near the solenoid.


1. Disconnect electrical wiring connector (5) at solenoid.
2. Disconnect vacuum harness at solenoid.
3. Remove solenoid and its support bracket (pull straight up).

INSTALLATION




1. Slip EVAP canister purge solenoid (2) onto its mounting bracket (3).
2. Connect vacuum harness to solenoid.
3. Connect electrical connector (5) to solenoid.