2003 JEEP GRAND CHEROKEE EVAP

BODY CONTROL MODULE C1 - GRAY 26 WAY
CAV CIRCUIT FUNCTION
1 Z132 20BK/OR GROUND
2 G52 20YL HEADLAMP SWITCH MUX
3 E19 20RD PANEL LAMPS DIMMER SIGNAL
4- -
5 G70 20BR/TN (BUILT-UP-EXPORT LHD
RHD)HOOD AJAR SWITCH SENSE
6 G26 20LB KEY-IN IGNITION SWITCH SENSE
7 G76 18TN/YL RIGHT REAR DOOR AJAR SWITCH SENSE
8 E2 20OR PANEL LAMPS DRIVER
9 E2 20OR PANEL LAMPS DRIVER
10 E2 20OR PANEL LAMPS DRIVER
11 - -
12 E2 20OR PANEL LAMPS DRIVER
13 E2 20OR PANEL LAMPS DRIVER
14 Z132 20BK/OR GROUND
15 D25 20YL/VT/WT PCI BUS
16 L80 20WT/DG HEADLAMP SWITCH RETURN
17 D19 20VT/OR BODY CONTROL MODULE FLASH ENABLE
18 - -
19 - -
20 G69 20BK/OR VTSS INDICATOR DRIVER
21 - -
22 V14 20RD/VT WIPER ON/OFF RELAY CONTROL
23 M20 20BR/OR COURTESY LAMP LOAD SHED
24 M2 20YL COURTESY LAMP DRIVER
25 Z234 20BK GROUND
26 - -
BODY CONTROL MODULE C2 - GRAY 22 WAY
CAV CIRCUIT FUNCTION
1 C103 20DG A/C SWITCH SIGNAL
2 V10 20BR WASHER PUMP SWITCH SENSE
3 V48 20RD/GY WIPER HIGH CONTROL
4 L40 20BR HIGH BEAM SWITCH SENSE
5 V11 20BK/TN WASHER FLUID SWITCH SENSE
6 P134 20TN/LG PASSENGER SEAT HEATER SWITCH MUX
7 P133 20TN/DG DRIVER SEAT HEATER SWITCH MUX
8 X20 20RD/YL RADIO CONTROL MUX
9 G31 20VT/LG AMBIENT TEMPERATURE SENSOR SIGNAL
10 L109 20WT ULTRALIGHT SENSOR SIGNAL
11 V52 20DG/RD WINDSHIELD WIPER SWITCH MUX
12 C81 20LB/WT REAR WINDOW DEFOGGER SWITCH SENSE
13 - -
14 - -
15 L27 20WT/TN FOG LAMP SWITCH SENSE
16 C201 20LB/YL EVAPORATOR TEMPERATURE SENSOR SIGNAL
17 G18 20PK/BK COOLANT LEVEL SWITCH SENSE
18 P132 20OR/BK SEAT HEATER SWITCH SENSOR GROUND
19 X10 20RD/BK RADIO CONTROL MUX RETURN
20 G32 20BK/LB SENSOR GROUND
21 L110 20BK/YL ULTRALIGHT SENSOR RETURN
22 V9 20WT/BK WINDSHIELD WIPER SWITCH RETURN
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 11

ENGINE OIL PRESSURE SENSOR (GAS) - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 K6 18VT/BK 5 VOLT SUPPLY
2 G60 18GY/YL ENGINE OIL PRESSURE SENSOR SIGNAL
3 K4 18BK/LB SENSOR GROUND
EVAP/PURGE SOLENOID (GAS) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
2 K52 18PK/BK (RHD) DUTY CYCLE EVAP/PURGE SOLENOID CONTROL
2 K52 20PK/BK (LHD) DUTY CYCLE EVAP/PURGE SOLENOID CONTROL
FRONT POWER OUTLET - RED 3 WAY
CAV CIRCUIT FUNCTION
1 F85 16VT (RHD) FUSED B(+)
1 F85 16VT/WT (LHD) FUSED B(+)
2- -
3 Z300 16BK GROUND
FRONT WASHER PUMP - WHITE 2 WAY
CAV CIRCUIT FUNCTION
1 V10 20BR WASHER PUMP SWITCH SENSE
2 Z141 20BK GROUND
FRONT WIPER MOTOR - BLACK 6 WAY
CAV CIRCUIT FUNCTION
1 V6 16DB FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
2 V55 16TN/RD WIPER PARK SWITCH SENSE
3- -
4 Z141 16BK GROUND
5 V3 16BR/WT WIPER HIGH/LOW RELAY LOW SPEED OUTPUT
6 V4 16RD/YL WIPER HIGH/LOW RELAY HIGH SPEED OUTPUT
8W - 80 - 78 8W-80 CONNECTOR PIN-OUTWJ

POWERTRAIN CONTROL MODULE C3 (GAS) - GRAY 32 WAY
CAV CIRCUIT FUNCTION
1 C13 18DB/OR A/C COMPRESSOR CLUTCH RELAY CONTROL
2- -
3 K51 18DB/YL AUTO SHUT DOWN RELAY CONTROL
4 V36 18TN/RD SPEED CONTROL VACUUM SOLENOID CONTROL
5 V35 18LG/RD SPEED CONTROL VENT SOLENOID CONTROL
6- -
7 K42 18DB/LG (4.7L HIGH OUTPUT) KNOCK SENSOR NO. 1 SIGNAL
8 K99 18BR/OR OXYGEN SENSOR 1/1 HEATER CONTROL
9 K512 18RD/YL (EXCEPT 4.0L
BUILT-UP-EXPORT)OXYGEN SENSOR DOWNSTREAM RELAY CONTROL
10 K106 18WT/DG (EXCEPT
BUILT-UP-EXPORT)LEAK DETECTION PUMP SOLENOID CONTROL
11 V32 18OR/DG SPEED CONTROL SUPPLY
12 F42 18DG/LG FUSED AUTO SHUT DOWN RELAY OUTPUT
13 T10 18YL/DG (4.7L RHD) TORQUE MANAGEMENT REQUEST SENSE
13 T6 18OR/WT (4.0L LHD) OVERDRIVE OFF SWITCH SENSE
13 T10 18DG/LG (4.7L LHD) TORQUE MANAGEMENT REQUEST SENSE
13 T6 18OR/BK (4.0L RHD) OVERDRIVE OFF SWITCH SENSE
14 K107 18OR/PK (EXCEPT
BUILT-UP-EXPORT)LEAK DETECTION PUMP SWITCH SENSE
15 K25 18VT/LG BATTERY TEMPERATURE SENSOR SIGNAL
16 K299 18BR/WT OXYGEN SENSOR 1/2 HEATER CONTROL
17 - -
18 K142 18GY/BK (4.7L HIGH OUTPUT) KNOCK SENSOR NO. 2 SIGNAL
19 K31 18BR FUEL PUMP RELAY CONTROL
20 K52 18PK/BK DUTY CYCLE EVAP/PURGE SOLENOID CONTROL
21 - -
22 - -
23 - -
24 K29 18WT/PK SECONDARY BRAKE SWITCH SIGNAL
25 K125 18WT/DB GENERATOR SOURCE
26 K226 18LB/YL FUEL LEVEL SENSOR SIGNAL
27 D21 18PK SCI TRANSMIT
28 - -
29 D32 18LG (LHD) SCI RECEIVE
29 D32 18LG/DG (RHD) SCI RECEIVE
30 D25 18VT/YL PCI BUS
31 - -
32 V37 18RD/LG SPEED CONTROL SWITCH SIGNAL
RADIATOR FAN MOTOR - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 C23 12DG RADIATOR FAN RELAY OUTPUT
2 Z4 12BK/PK GROUND
8W - 80 - 110 8W-80 CONNECTOR PIN-OUTWJ

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Driver Power Seat Horizontal
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Rear Riser
MotorRD At Driver Seat N/S
Driver Power Seat Rear Riser
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Recliner
MotorBK At Driver Seat N/S
Driver Power Seat Recliner
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Switch
(Midline/Premium)GN At Driver Seat N/S
Driver Rear Power Window
MotorBK In Left Rear Door 28
Driver Rear Power Window
SwitchBL In Left Rear Door 28
Driver Seat Belt Switch At Switch N/S
EGR Solenoid (Diesel) BK Left Front Fender 7, 8
Electric Brake BL Near Junction Block N/S
Electronic Speed Control Servo BK Right Front of Engine Compartment 5
Engine Control Module C1
(Diesel)BK Left Front of Engine 7, 8
Engine Control Module C2
(Diesel)BK Left Front of Engine 7, 8
Engine Coolant Temperature
Sensor (Diesel)BK Top of Engine N/S
Engine Coolant Temperature
Sensor (GAS)BK Front of Engine 9, 13
Engine Oil Pressure Sensor BK Side of Engine 10, 11, 13
EVAP/Purge Solenoid BK Left Front Fender Near Controller
Antilock Brake3
Front Power Outlet RD Center of Instrument Panel 19, 20
Front Washer Pump WT Left Front of Engine Compartment 3, 4
Front Wiper Motor BK Left Side of Cowl 3, 4
Fuel Injector No.1 BK At Injector 7, 9, 13
Fuel Injector No.2 BK At Injector 7, 9, 14, 15
Fuel Injector No.3 BK At Injector 7, 9, 13
Fuel Injector No.4 BK At Injector 7, 9, 14, 15
Fuel Injector No.5 BK At Injector 9, 13
Fuel Injector No.6 BK At Injector 9, 14, 15
Fuel Injector No.7 (4.7L) BK At Injector 13
Fuel Injector No.8 (4.7L) BK At Injector 14, 15
Fuel Pressure Sensor (Diesel) BK Right Front of Engine N/S
Fuel Pressure Solenoid
(Diesel)BK Top of Engine N/S
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 5
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

SPLICE
NUMBERLOCATION FIG.
S122 (4.0L) Near T/O for G103 10, 11
S122 (4.7L) LHD Near T/O for Input Speed Sensor 15
S122 (4.7L) RHD Near T/O for Powertrain Control Module 16
S122 (Diesel) Near T/O for Generator N/S
S123 (4.0L) Near T/O for Capacitor 10, 11
S124 (4.7L) In Trough Near T/O for Capacitor No.2 13
S125 (Diesel) In T/O for C103 and C105 Left Rear of Engine Compartment N/S
S125 (Gas) Near T/O for Powertrain Control Module - C3 N/S
S126 (4.0L) LHD Near T/O for Battery Temperature Sensor N/S
S126 (4.0L) RHD In Trough Near T/O for Powertrain Control Module - C3 N/S
S127 (LHD) Gas In Trough Near T/O for Powertrain Control Module - C3 N/S
S127 (RHD) Gas In T/O for Power Distribution Center 5
S127 (Diesel) Near T/O for Power Distribution Center 4
S128 (Diesel) In T/O for C102 Left Rear of Engine Compartment N/S
S128 (LHD) Gas In Trough Near T/O for Powertrain Control Module - C3 N/S
S128 (RHD) Gas In T/O for C102 5
S130 (LHD) Gas In T/O for C102 N/S
S130 (RHD) Gas In T/O for Controller Antilock Brake 3
S130 (Diesel) In T/O for Controller Anti-Lock Brake 4
S131 In Trough Near T/O for Power Distribution Center 5
S131 (Diesel) Near T/O for Power Distribution Center 4
S132 (Diesel) Near T/O for EGR Solenoid N/S
S132 (Gas) Near T/O for Battery Temperature Sensor 5
S133 (Diesel) In Trough Near T/O for EGR Solenoid N/S
S133 (Gas) Near T/O for Battery Temperature Sensor 5
S134 (Diesel) In Trough Near T/O for G106/G107 4
S134 (Gas) In Trough Near T/O for Controller Anti-Lock Brake 3
S135 (Diesel) Near T/O for Engine Control Module C1 7, 8
S136 (Diesel) Near T/O for Engine Control Module C1 7, 8
S137 (Diesel) In Trough Near T/O for Coolant Level Sensor N/S
S139 (Diesel) Near T/O for Engine Control Module C1 7, 8
S140 (Diesel) Near T/O for Power Distribution Center 4
S140 (Gas) Near T/O for Controller Antilock Brake N/S
S141 (Gas) Near T/O for Controller Antilock Brake 3
S142 (Diesel) In Trough Near T/O for Coolant Level Sensor N/S
S142 Gas In T/O for C102 5
S143 (Diesel) In Trough Near T/O for Hood Ajar Switch 4
S143 (Gas,
Built-Up-Export)
LHDIn Trough Near T/O for Controller Antilock Brake 3
S143 Gas RHD Near T/O for Evap/Purge Solenoid N/S
S145 (Diesel) Near T/O for Engine Control Module C1 7, 8
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 13
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
3. Thin or diluted oil 3. Change oil to correct viscosity.
4. Excessive main bearing clearance 4. Measure bearings for correct
clearance. Repair as necessary
5. Excessive end play 5. Check crankshaft thrust bearing for
excessive wear on flanges
6. Crankshaft main journal out of
round or worn6. Grind journals or replace
crankshaft
7. Loose flywheel or torque converter 7. Inspect crankshaft, flexplate/
flywheel and bolts for damage.
Tighten to correct torque
LOW OIL PRESSURE 1. Low oil level 1. Check oil level and fill if necessary
2. Faulty oil pressure sending unit 2. Install new sending unit
3. Clogged oil filter 3. Install new oil filter
4. Worn oil pump 4. Replace oil pump assembly.
5. Thin or diluted oil 5. Change oil to correct viscosity.
6. Excessive bearing clearance 6. Measure bearings for correct
clearance
7. Oil pump relief valve stuck 7. Remove valve to inspect, clean
and reinstall
8. Oil pump suction tube loose,
broken, bent or clogged8. Inspect suction tube and clean or
replace if necessary
9. Oil pump cover warped or cracked 9. Install new oil pump
OIL LEAKS 1. Misaligned or deteriorated gaskets 1. Replace gasket
2. Loose fastener, broken or porous
metal part2. Tighten, repair or replace the part
3. Front or rear crankshaft oil seal
leaking3. Replace seal
4. Leaking oil gallery plug or cup
plug4. Remove and reseal threaded plug.
Replace cup style plug
EXCESSIVE OIL
CONSUMPTION OR SPARK
PLUGS OIL FOULED1. CCV System malfunction 1. (Refer to 25 - EMISSIONS
CONTROL/EVAPORATIVE
EMISSIONS - DESCRIPTION) for
correct operation
2. Defective valve stem seal(s) 2. Repair or replace seal(s)
3. Worn or broken piston rings 3. Hone cylinder bores. Install new
rings
4. Scuffed pistons/cylinder walls 4. Hone cylinder bores and replace
pistons as required
5. Carbon in oil control ring groove 5. Remove rings and de-carbon
piston
6. Worn valve guides 6. Inspect/replace valve guides as
necessary
7. Piston rings fitted too tightly in
grooves7. Remove rings and check ring end
gap and side clearance. Replace if
necessary
WJENGINE - 4.0L 9 - 7
ENGINE - 4.0L (Continued)

FUEL DELIVERY
DESCRIPTION
The fuel delivery system consists of:
²the fuel pump module containing the electric
fuel pump, fuel gauge sending unit (fuel level sensor)
and a separate fuel filter located at bottom of pump
module
²a separate combination fuel filter/fuel pressure
regulator
²fuel tubes/lines/hoses
²quick-connect fittings
²fuel injector rail
²fuel injectors
²fuel tank
²fuel tank filler/vent tube assembly
²fuel tank filler tube cap
²accelerator pedal
²throttle cable
OPERATION
The fuel tank assembly consists of: the fuel tank,
fuel tank shield, fuel tank straps, fuel pump module
assembly, fuel pump module locknut/gasket, and fuel
tank check valve (refer to Emission Control System
for fuel tank check valve information).
A fuel filler/vent tube assembly using a pressure/
vacuum, 1/4 turn fuel filler cap is used. The fuel
filler tube contains a flap door located below the fuel
fill cap.
Also to be considered part of the fuel system is the
evaporation control system. This is designed to
reduce the emission of fuel vapors into the atmo-
sphere. The description and function of the Evapora-
tive Control System is found in Emission Control
Systems.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
DIAGNOSIS AND TESTING
FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation:The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not oper-
ational. It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline willremain in fuel supply line between the check valve
and fuel injectors.Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition.When the elec-
tric fuel pump is activated, fuel pressure should
immediately(1±2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hotengine that has been shut down for a short
period of time may be caused by:
²Fuel pressure bleeding past a fuel injector(s).
²Fuel pressure bleeding past the check valve in
the fuel pump module.
²A defective fuel filter/pressure regulator.
Two #6539, 5/16º, Fuel Line Pressure Test Adapter
Hose Tools are required for the following tests.
(1) Release fuel system pressure. Refer to Fuel
Pressure Release Procedure.
(2) Raise vehicle.
Fuel Line Identification:The fuel filter/pressure
regulator is located in front of the fuel tank and
above the rear axle. It is transversely mounted to a
chassis crossmember (left-to-right). The filter/regula-
tor is equipped with 3 fuel line fittings (2 at one end
and 1 at the other end). The single fitting facing the
left side of the vehicle is the supply line to the fuel
rail (Fig. 1) . The 2 fittings facing the right side of
the vehicle are connected to the fuel tank. Of these 2
fittings, the fitting towards thefrontis used for fuel
return to the fuel tank. The fitting towards therear
is a pressure line. Thisrearfitting must be discon-
nected for the following step.
(3) See previous step. Disconnect fuel pressure line
atrearof filter/regulator. This is a 5/169quick-con-
nect fitting (Fig. 1) . Refer to Quick-Connect Fittings
for procedures.
(4) Obtain correct Fuel Line Pressure Test Adapter
Hose Tool # 6539 for 5/16º fuel lines. Connect one
end of this Special Tool into the disconnected fuel
pressure line. Connect the other end of the Tool into
fitting on filter/regulator.
(5) Lower vehicle.
(6) Disconnect the fuel inlet line at fuel rail. Refer
to Quick-Connect Fittings for procedures. On some
engines, air cleaner housing removal may be neces-
sary before fuel line disconnection.
(7) Obtain a second Fuel Line Pressure Test
Adapter Hose Tool # 6539 for 5/16º fuel lines. Con-
nect this tool between disconnected fuel line and fuel
rail (Fig. 2) .
(8) Connect the 0-414 kPa (0-60 psi) fuel pressure
test gauge (from Gauge Set 5069) to the test port on
the appropriate Adaptor Tool.NOTE: The DRB III
Scan Tool along with the PEP module, the 500
psi pressure transducer, and the transducer-to-
test port adapter may also be used in place of
the fuel pressure gauge.
14 - 2 FUEL DELIVERYWJ

CAUTION: The fittings on both tools must be in
good condition and free from any small leaks
before performing the proceeding test.
(9) Start engine and bring to normal operating
temperature.
(10) Observe fuel pressure test gauge (or DRB
screen). Normal operating pressure should be 339
kPa   34 kPa (49.2 psi   5 psi).
(11) Shut engine off.
(12) Pressure should not fall below30 psi for five
minutes.
(13) If pressure falls below 30 psi, it must be
determined if a fuel injector, the supply check valve
within the fuel pump module, the fuel filter/pressure
regulator, or a fuel tube/line is leaking.
(14) Again, start engine and bring to normal oper-
ating temperature.
(15) Shut engine off.
(16)Testing for fuel injector or fuel rail leak-
age:Clamp off the rubber hose portion of the 6539
Adaptor Tool between the fuel rail and the test port
ªTº on Adapter Tool (be sure clamping pressure issufficient). If pressure now holds at or above 30 psi, a
fuel injector or the fuel rail is leaking.
(17) Again, start engine and bring to normal oper-
ating temperature.
(18) Shut engine off.
(19) Raise vehicle.
(20)Testing for fuel filter/pressure regulator
leakage:While continuing to securely clamp
between the fuel rail and the test port9T9on Adaptor
Tool 6539, securely clamp offanyrubber hose por-
tion of the Adaptor Tool 6539 that was installed
between the fuel pressure line and the filter/regula-
tor fitting (by restricting the pump module supply
line's backflow, you isolate any leakdown originating
from the filter/regulator via the tank return line.) If
the pressure falls below 30 psi within 5 minutes, the
filter/regulator is leaking. If it now holds at or above
30 psi, the electric fuel pump check valve is leaking
or a fuel tube/line is leaking. A fuel odor presence
would indicate the latter.
The electric fuel pump is not serviced separately. If
replacement is necessary, replace the fuel pump mod-
ule assembly. The filter/regulator may be replaced
separately. Refer to Fuel Filter/Fuel Pressure Regu-
lator Removal/Installation for additional information.
Fig. 1 Disconnect Fuel Pressure Line at Filter/
Regulator
1 - FUEL SUPPLY LINE (TO FUEL RAIL)
2 - EVAP LINE
3 - FUEL RETURN LINE (MALE)
4 - FUEL PRESSURE LINE (FEMALE)
5 - FUEL FILTER/PRESSURE REGULATOR
6 - FUEL TANK
Fig. 2 Connecting Adapter ToolÐTypical
1 - VEHICLE FUEL LINE
2 - TEST PORT ªTº
3 - SPECIAL TOOL 6923, 6631, 6541 OR 6539
4 - FUEL PRESSURE TEST GAUGE
5 - FUEL LINE CONNECTION AT RAIL
6 - FUEL RAIL
WJFUEL DELIVERY 14 - 3
FUEL DELIVERY (Continued)