RAM 2500 Van V8-5.9L VIN Z (1997)
Canister Purge Solenoid: Description and Operation
Fig. 2 EVAP Purge Solenoid
DESCRIPTION
All engines use a duty cycle EVAP canister purge solenoid. The solenoid regulates the rate of vapor flow from the EVAP canister to the throttle
body. The Jeep/Truck Engine Controller (JTEC) operates the solenoid.
OPERATION
During the cold start warm-up period and the hot start time delay, the JTEC does not energize the solenoid. When de-energized, no vapors are
purged. The JTEC deenergizes 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 JTEC
energizes and de-energizes the solenoid 5 or 10 times per second, depending upon operating conditions. The JTEC varies the vapor flow rate by
changing solenoid pulse width. Pulse width is the amount of time the solenoid energizes. The JTEC adjusts solenoid pulse width based on engine
operating condition.
CIRCUIT OPERATION
The Powertrain Control Module (PCM) operates the EVAP/Purge solenoid by providing a ground path on circuit K52. Circuit K52 connects to
PCM cavity C20. Circuit F18 supplies battery voltage to the EVAP/Purge solenoid.
