Table of Contents
Advertisement
25 - 12
EMISSION CONTROL SYSTEMS
DESCRIPTION AND OPERATION (Continued)
SOLENOID
ELECTRICAL
CONNECTOR
Location
CANISTER
MOUNTING
BOLT
EVAP
CANISTER ~_
_
TANG
PURGE
SOLENOID
~~
0a4a5d0
Fig. 2 EVAP Canister and Canister Purge Solenoid
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the sole-
noid. When de-energized, no vapors are purged . The
PCM de-energizes the solenoid during open loop oper-
ation .
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 condi-
tions . The PCM varies the vapor flow rate by chang-
ing solenoid pulse width. Pulse width is the amount
of time that the solenoid is energized . The PCM
adjusts solenoid pulse width based on engine operat-
ing condition .
The solenoid attaches to a bracket located in the
engine compartment near the EVAP canister (Fig. 2) .
The top of the solenoid has the word UP or TOP on
it. The solenoid will not operate properly unless it is
installed correctly.
FUEL TANK FILLER TUBE CAP
The fuel tank is sealed with a pressure-vacuum
relief fuel tank filler tube cap (Fig . 3) . The relief
valves in the cap are a safety feature . They operate
only to prevent excessive pressure or vacuum in tank
caused by a malfunction in system or damage to vent
lines .
The cap has a threaded configuration . This allows
the seal to be broken and pressure to be relieved
without separation of cap from filler tube. Approxi-
mately two and a half turns are required to remove
the cap.
If replacement of filler tube cap is necessary, it
must be replaced with an identical cap to be sure of
correct system operation .
CUT-AWAY
GASKET
Fig. 3 Fuel Tank Filler Tube Cap-Typical
TJ
RN348
CAUTION :
Remove the fuel tank filler tube cap
(fuel tank cap) to relieve any fuel tank pressure . The
cap must be removed prior to disconnecting any
fuel system component or before draining the fuel
tank.
CRANKCASE VENTILATION SYSTEM
All 2 .5L 4-cylinder and 4 .OL 6-cylinder engines
are equipped with a Crankcase Ventilation (CCV)
system (Fig. 4) or (Fig . 5) . The CCV system performs
the same function as a conventional PCV system, but
does not use a vacuum controlled valve.
AIR
TUBE
FIXED
ORIFICE
FITTING
Fig. 4 CCV System 2.5L Engine
CCV
TUBE
80a4a5d8
On 4 .OL 6-cylinder engines, a molded vacuum tube
connects manifold vacuum to top of cylinder head
(valve) cover at dash panel end . The vacuum fitting
Advertisement
Table of Contents
Troubleshooting
