2003 JEEP GRAND CHEROKEE EVAP

(8)Do not attempt to clean the old PCV valve.
(9) Return PCV valve back to oil filler tube by
placing valve locating tabs (Fig. 21) into cam lock.
Press PCV valve in and rotate valve upward. A slight
click will be felt when tabs have engaged cam lock.
Valve should be pointed towards rear of vehicle.
(10) Connect PCV line/hose and connecting rubber
hose to PCV valve.
(11) Disconnect rubber hose from fresh air fitting
at left side of air cleaner resonator box (Fig. 22).
Start engine and bring to idle speed. Hold a piece of
stiff paper (such as a parts tag) loosely over the
opening of the disconnected rubber hose.
(12) The paper should be drawn against the hose
opening with noticeable force. This will be after
allowing approximately one minute for crankcase
pressure to reduce.
(13) If vacuum is not present, disconnect each PCV
system hose at top of each breather (Fig. 22). Check
for obstructions or restrictions.(14) If vacuum is still not present, remove each
PCV system breather (Fig. 22) from each cylinder
head. Check for obstructions or restrictions. If
plugged, replace breather. Tighten breather to 12
N´m (106 in. lbs.) torque. Do not attempt to clean
breather
(15) If vacuum is still not present, disconnect each
PCV system hose at each fitting and check for
obstructions or restrictions.
Fig. 21 PCV Valve/Oil Filler TubeÐ4.7L V-8 Engine
1 - O-RING
2 - LOCATING TABS
3 - CAM LOCK
4 - OIL FILLER TUBE
5 - PCV LINE/HOSE
6 - P C V VA LV E
Fig. 22 PCV Breathers/Tubes/HosesÐ4.7L V-8
Engine
1 - FRESH AIR FITTING
2 - CONNECTING TUBES/HOSES
3 - CRANKCASE BREATHERS (2)
4 - RUBBER HOSE
5 - AIR CLEANER RESONATOR
25 - 38 EVAPORATIVE EMISSIONSWJ
PCV VALVE (Continued)

REMOVAL - PCV VALVE - 4.7L
The PCV valve is located on the oil filler tube (Fig.
23). Two locating tabs are located on the side of the
valve (Fig. 23). These 2 tabs fit into a cam lock in the
oil filler tube. An o-ring seals the valve to the filler
tube.
(1) Disconnect PCV line/hose (Fig. 23) by discon-
necting rubber hose at PCV valve fitting.
(2) Remove PCV valve at oil filler tube by rotating
PCV valve downward (counter-clockwise) until locat-
ing tabs have been freed at cam lock (Fig. 23). After
tabs have cleared, pull valve straight out from filler
tube.To prevent damage to PCV valve locating
tabs, valve must be pointed downward for
removal. Do not force valve from oil filler tube.
(3) After valve is removed, check condition of valve
o-ring (Fig. 23).
INSTALLATION - PCV VALVE - 4.7L
The PCV valve is located on the oil filler tube (Fig.
23). Two locating tabs are located on the side of the
valve (Fig. 23). These 2 tabs fit into a cam lock in the
oil filler tube. An o-ring seals the valve to the filler
tube.
(1) Return PCV valve back to oil filler tube by
placing valve locating tabs (Fig. 23) into cam lock.
Press PCV valve in and rotate valve upward. A slight
click will be felt when tabs have engaged cam lock.
Valve should be pointed towards rear of vehicle.
(2) Connect PCV line/hose and rubber hose to PCV
valve.
VACUUM LINES
DESCRIPTION
A vacuum schematic for emission related items can
be found on the VECI label. Refer to Vehicle Emis-
sion Control Information (VECI) Label for label loca-
tion.
VAPOR CANISTER
DESCRIPTION
A maintenance free, EVAP canister is used on all
gasoline powered models. The canister is attached to
a two-piece support bracket located behind the left-
rear wheel.
OPERATION
The EVAP canister is filled with granules of an
activated carbon mixture. Fuel vapors entering the
EVAP canister are absorbed by the charcoal granules.
The canister serves two functions: as a temporary
fuel vapor storage point while refueling the vehicle
for the ORVR system, as a temporary vapor storage
point while the engine is running.
Fuel tank pressure vents into the EVAP canister.
Fuel vapors are temporarily held in the canister until
they can be drawn into the intake manifold. The duty
cycle EVAP canister purge solenoid allows the EVAP
canister to be purged at predetermined times and at
certain engine operating conditions.
Refer to ORVR for additional information.
Fig. 23 PCV Valve/Oil Filler Tube Location
1 - O-RING
2 - LOCATING TABS
3 - CAM LOCK
4 - OIL FILLER TUBE
5 - PCV LINE/HOSE
6 - P C V VA LV E
WJEVAPORATIVE EMISSIONS 25 - 39
PCV VALVE (Continued)

REMOVAL
The EVAP canister is located behind the left-rear
wheel (Fig. 24). It is attached to a two-piece support
bracket (Fig. 25).
(1) Remove rear bumper facia. Refer to Rear Facia
Removal / Installation in Frame & Bumpers section.
(2) Remove 1 support bracket brace bolt (Fig. 25).
(3) Loosen, but do not remove 2 support bracket
nuts (Fig. 26).
(4) Remove upper/rear support bracket mounting
bolt (Fig. 27).
(5) Carefully lower support bracket assembly to
gain access to vapor / vacuum lines. To prevent dam-
age to lines, suspend bracket assembly with rope or
string.
(6) Disconnect necessary vacuum / vapor lines at
EVAP canister.
(7) Remove EVAP canister mounting bolt (Fig. 28).
(8) Lift canister from support bracket (2 pins are
used to align canister into support bracket)
INSTALLATION
The EVAP canister is located behind the left-rear
wheel (Fig. 24). It is attached to a two-piece support
bracket (Fig. 25).
(1) Position canister to support bracket. Guide 2
alignment pins into support bracket.
(2) Install EVAP canister mounting bolt (Fig. 28).
Refer to Torque Specifications.
(3) Carefully install vapor / vacuum lines to canis-
ter.The vapor/vacuum lines and hoses must be
firmly connected. Check the vapor/vacuum
lines at the LDP, LDP filter and EVAP canister
purge solenoid for damage or leaks. If a leak is
present, a Diagnostic Trouble Code (DTC) may
be set.
Fig. 24 LOCATION, LDP / EVAP CANISTER
1 - LEAK DETECTION PUMP
2 - EVAP CANISTER
Fig. 25 TWO-PIECE SUPPORT BRACKET
1 - TWO-PIECE SUPPORT BRACKET (FRONT)
2 - SUPPORT BRACKET BRACE
3 - TWO-PIECE SUPPORT BRACKET (REAR)
4 - SUPPORT BRACKET ATTACHING BOLTS (3)
5 - SUPPORT BRACKET BRACE BOLT
25 - 40 EVAPORATIVE EMISSIONSWJ
VAPOR CANISTER (Continued)

(4) Carefully raise support bracket assembly to
frame rail. Install 1 support bracket brace bolt (Fig.
25) and 2 support bracket nuts (Fig. 26).
(5) Install upper/rear support bracket mounting
bolt (Fig. 27). Refer to Torque Specifications.
(6) Install rear bumper facia. Refer to Rear Facia
Removal / Installation in Frame & Bumpers section.
Fig. 27 SUPPORT BRACKET BOLT
1 - EVAP CANISTER
2 - UPPER / REAR SUPPORT BRACKET BOLT
3 - SLOTTED HOLE
4 - ALIGNMENT PINS (2)
5 - TWO-PIECE SUPPORT BRACKET
Fig. 28 EVAP CANISTER REMOVE / INSTALL
1 - EVAP CANISTER MOUNTING BOLT
2 - SLOTTED HOLE
3 - EVAP CANISTER (LOWERED)
Fig. 26 SUPPORT BRACKET NUTS
1 - SUPPORT BRACKET NUTS (2)
2 - SUPPORT BRACKET (FRONT)
3 - SUPPORT BRACKET BRACE BOLT
4 - LDP MOUNTING BOLTS (3)
WJEVAPORATIVE EMISSIONS 25 - 41
VAPOR CANISTER (Continued)