8w- JEEP GRAND CHEROKEE 2003 WJ / 2.G User Guide

STANDARD PROCEDURE - TESTING OF
VOLTAGE POTENTIAL
(1) Connect the ground lead of a voltmeter to a
known good ground (Fig. 7).
(2) Connect the other lead of the voltmeter to the
selected test point. The vehicle ignition may need to
be turned ON to check voltage. Refer to the appropri-
ate test procedure.
STANDARD PROCEDURE - TESTING FOR
CONTINUITY
(1) Remove the fuse for the circuit being checked
or, disconnect the battery.
(2) Connect one lead of the ohmmeter to one side
of the circuit being tested (Fig. 8).
(3) Connect the other lead to the other end of the
circuit being tested. Low or no resistance means good
continuity.
STANDARD PROCEDURE - TESTING FOR A
SHORT TO GROUND
(1) Remove the fuse and disconnect all items
involved with the fuse.
(2) Connect a test light or a voltmeter across the
terminals of the fuse.
(3) Starting at the fuse block, wiggle the wiring
harness about six to eight inches apart and watch
the voltmeter/test lamp.
(4) If the voltmeter registers voltage or the test
lamp glows, there is a short to ground in that gen-
eral area of the wiring harness.
Fig. 7 TESTING FOR VOLTAGE POTENTIAL
Fig. 8 TESTING FOR CONTINUITY
1 - FUSE REMOVED FROM CIRCUIT
WJ8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 9
WIRING DIAGRAM INFORMATION (Continued)

STANDARD PROCEDURE - TESTING FOR A
SHORT TO GROUND ON FUSES POWERING
SEVERAL LOADS
(1) Refer to the wiring diagrams and disconnect or
isolate all items on the suspected fused circuits.
(2) Replace the blown fuse.
(3) Supply power to the fuse by turning ON the
ignition switch or re-connecting the battery.
(4) Start connecting or energizing the items in the
fuse circuit one at a time. When the fuse blows the
circuit with the short to ground has been isolated.
STANDARD PROCEDURE - TESTING FOR A
VOLTAGE DROP
(1) Connect the positive lead of the voltmeter to
the side of the circuit closest to the battery (Fig. 9).
(2) Connect the other lead of the voltmeter to the
other side of the switch, component or circuit.
(3) Operate the item.
(4) The voltmeter will show the difference in volt-
age between the two points.
SPECIAL TOOLS
WIRING/TERMINAL
Fig. 9 TESTING FOR VOLTAGE DROP
PROBING TOOL PACKAGE 6807
TERMINAL PICK TOOL SET 6680
TERMINAL REMOVING TOOLS 6932 AND 8638
TERMINAL REMOVING TOOL 6934
8W - 01 - 10 8W-01 WIRING DIAGRAM INFORMATIONWJ
WIRING DIAGRAM INFORMATION (Continued)

CONNECTOR
REMOVAL
(1) Disconnect battery.
(2) Release Connector Lock (Fig. 10).
(3) Disconnect the connector being repaired from
its mating half/component.
(4) Remove the dress cover (if applicable) (Fig. 10).
(5) Release the Secondary Terminal Lock, if
required (Fig. 11).
(6) Position the connector locking finger away from
the terminal using the proper special tool. Pull on
the wire to remove the terminal from the connector
(Fig. 12).
INSTALLATION
(1) Insert the removed terminal in the same cavity
on the repair connector.
(2) Repeat steps for each terminal in the connec-
tor, being sure that all wires are inserted into the
proper cavities. For additional connector pin-out
identification, refer to the wiring diagrams.
(3) When the connector is re-assembled, the sec-
ondary terminal lock must be placed in the locked
position to prevent terminal push out.
(4) Replace dress cover (if applicable).
(5) Connect connector to its mating half/compo-
nent.
(6) Connect battery and test all affected systems.
Fig. 10 REMOVAL OF DRESS COVER
1 - DRESS COVER
2 - CONNECTOR LOCK
3 - CONNECTOR
WJ8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 11

Fig. 11 EXAMPLES OF CONNECTOR SECONDARY TERMINAL LOCKS
1 - Secondary Terminal Lock
8W - 01 - 12 8W-01 WIRING DIAGRAM INFORMATIONWJ
CONNECTOR (Continued)

Fig. 12 TERMINAL REMOVAL
1 - TYPICAL CONNECTOR
2 - PICK FROM SPECIAL TOOL KIT 6680
3 - APEX CONNECTOR
4 - PICK FROM SPECIAL TOOL KIT 6680
5 - AUGAT CONNECTOR
6 - SPECIAL TOOL 6932
7 - MOLEX CONNECTOR8 - SPECIAL TOOL 6742
9 - THOMAS AND BETTS CONNECTOR
10 - SPECIAL TOOL 6934
11 - TYCO CONNECTOR
12 - SPECIAL TOOL 8638
WJ8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 13
CONNECTOR (Continued)

DIODE
REMOVAL
(1) Disconnect the battery.
(2) Locate the diode in the harness, and remove
the protective covering.
(3) Remove the diode from the harness, pay atten-
tion to the current flow direction (Fig. 13).
INSTALLATION
(1) Remove the insulation from the wires in the
harness. Only remove enough insulation to solder in
the new diode.
(2) Install the new diode in the harness, making
sure current flow is correct. If necessary, refer to the
appropriate wiring diagram for current flow (Fig. 13).
(3) Solder the connection together using rosin core
type solder only.Do not use acid core solder.
(4) Tape the diode to the harness using electrical
tape. Make sure the diode is completely sealed from
the elements.
(5) Re-connect the battery and test affected sys-
tems.
TERMINAL
REMOVAL
(1) Follow steps for removing terminals described
in the connector removal section.
(2) Cut the wire 6 inches from the back of the con-
nector.
INSTALLATION
(1) Select a wire from the terminal repair kit that
best matches the color and gage of the wire being
repaired.
(2) Cut the repair wire to the proper length and
remove one±half (1/2) inch of insulation.
(3) Splice the repair wire to the wire harness (see
wire splicing procedure).
(4) Insert the repaired wire into the connector.
(5) Install the connector locking wedge, if required,
and reconnect the connector to its mating half/compo-
nent.
(6) Re-tape the wire harness starting at 1±1/2
inches behind the connector and 2 inches past the
repair.
(7) Connect battery and test all affected systems.
Fig. 13 DIODE IDENTIFICATION
1 - CURRENT FLOW
2 - BAND AROUND DIODE INDICATES CURRENT FLOW
3 - DIODE AS SHOWN IN THE DIAGRAMS
8W - 01 - 14 8W-01 WIRING DIAGRAM INFORMATIONWJ

WIRE
STANDARD PROCEDURE - WIRE SPLICING
When splicing a wire, it is important that the cor-
rect gage be used as shown in the wiring diagrams.
(1) Remove one-half (1/2) inch of insulation from
each wire that needs to be spliced.
(2) Place a piece of adhesive lined heat shrink tub-
ing on one side of the wire. Make sure the tubing will
be long enough to cover and seal the entire repair
area.
(3) Place the strands of wire overlapping each
other inside of the splice clip (Fig. 14).
(4) Using crimping tool, Mopar p/n 05019912AA,
crimp the splice clip and wires together (Fig. 15).(5) Solder the connection together using rosin core
type solder only (Fig. 16).
CAUTION: DO NOT USE ACID CORE SOLDER.
(6) Center the heat shrink tubing over the joint
and heat using a heat gun. Heat the joint until the
tubing is tightly sealed and sealant comes out of both
ends of the tubing (Fig. 17).
Fig. 14 SPLICE BAND
1 - SPLICE BAND
Fig. 15 CRIMPING TOOL
1 - CRIMPING TOOL
Fig. 16 SOLDER SPLICE
1 - SOLDER
2 - SPLICE BAND
3 - SOLDERING IRON
Fig. 17 HEAT SHRINK TUBE
1 - SEALANT
2 - HEAT SHRINK TUBE
WJ8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 15

8W-02 COMPONENT INDEX
Component Page
A/C Compressor Clutch................. 8W-42
A/C Pressure Transducer................ 8W-42
Accelerator Pedal Position Sensor......... 8W-30
Accessory Delay Relay.................. 8W-64
Adjustable Pedals..................... 8W-30
Airbags............................. 8W-43
Ambient Temperature Sensor............ 8W-45
Antennas............................ 8W-47
Ash Receiver Lamp.................... 8W-44
Auto Shut Down Relay................. 8W-30
Automatic Day/Night Mirror............. 8W-49
Automatic Headlamp Light Sensor/VTSS
LED.............................. 8W-39
Automatic Zone Control Module.......... 8W-42
Back-Up Lamp Relay................... 8W-51
Battery Temperature Sensor............. 8W-30
Battery............................. 8W-20
Blend Door Motor/Actuator.............. 8W-42
Blower Motor......................... 8W-42
Body Control Module................... 8W-45
Boost Pressure Sensor.................. 8W-30
Brake Lamp Switch.................... 8W-33
Camshaft Position Sensor............... 8W-30
Capacitors........................... 8W-30
Cargo Lamp.......................... 8W-44
Center High Mounted Stop Lamp......... 8W-51
Cigar Lighter......................... 8W-41
Circuit Breakers...................... 8W-12
Clockspring.................. 8W-33, 41, 43, 47
Coil On Plugs......................... 8W-30
Coil Rail............................. 8W-30
Combination Flasher................... 8W-52
Compact Disc Changer.................. 8W-47
Controller Antilock Brake............... 8W-35
Coolant Level Sensor................... 8W-45
Courtesy Lamps....................... 8W-44
Crankcase Heater..................... 8W-30
Crankshaft Position Sensor.............. 8W-30
Cylinder Lock Switches................. 8W-61
Data Link Connector................... 8W-18
Diagnostic Junction Port................ 8W-18
EGR Solenoid......................... 8W-30
Electric Brake........................ 8W-54
Electronic Speed Control Servo........... 8W-33
Engine Control Module................. 8W-30
Engine Coolant Temperature Sensor...... 8W-30
Engine Oil Pressure Sensor.............. 8W-30
Engine Starter Motor................... 8W-21
EVAP/Purge Solenoid................... 8W-30
Fog Lamps........................ 8W-50, 51
Fuel Injectors......................... 8W-30
Fuel Pressure Sensor................... 8W-30Component Page
Fuel Pressure Solenoid................. 8W-30
Fuel Pump........................... 8W-30
Fuel Tank Module..................... 8W-30
Fuses............................ 8W-10, 12
Fusible Link....................... 8W-10, 20
Grounds............................. 8W-15
Generator......................... 8W-20, 30
Glove Box Lamp...................... 8W-44
Glow Plugs........................... 8W-30
Headlamp Leveling Motor............... 8W-50
Heated Seats......................... 8W-63
High Beam Headlamps................. 8W-50
Hood Ajar Switch...................... 8W-39
Horns............................... 8W-41
Hydraulic Cooling Module............ 8W-30, 42
Idle Air Control Motor.................. 8W-30
Ignition Switch....................... 8W-10
Impact Sensors....................... 8W-43
Input Speed Sensor.................... 8W-31
Instrument Cluster.................... 8W-40
Intake Air Temperature Sensor........... 8W-30
Intake Port Swirl Actuator.............. 8W-30
Intrusion Transceiver Module............ 8W-49
Junction Block........................ 8W-12
Knock Sensor......................... 8W-30
Lamp Assemblies................... 8W-51, 52
Leak Detection Pump.................. 8W-30
License Lamps........................ 8W-51
Liftgate............................. 8W-61
Line Pressure Sensor................... 8W-31
Low Beam Headlamps.................. 8W-50
Low Beam Relay...................... 8W-50
Low Beam/Daytime Running Lamp Relay . . . 8W-50
Lumbar Motor........................ 8W-63
Lumbar Switch....................... 8W-63
Manifold Absolute Pressure Sensor........ 8W-30
Manual Temperature Control............. 8W-42
Mass Air Flow Sensor.................. 8W-30
Memory Set Switch................. 8W-62, 63
Mode Door Motor/Actuator............... 8W-42
Multi-Function Switch............... 8W-50, 53
Output Speed Sensor................... 8W-31
Overhead Map/Courtesy Lamp........... 8W-44
Oxygen Sensors....................... 8W-30
Park Brake Switch..................... 8W-40
Park Lamp........................... 8W-50
Park/Neutral Position Switch............ 8W-31
Park/Turn Signal Lamps................ 8W-50
Power Amplifier....................... 8W-47
Power Connector...................... 8W-41
Power Distribution Center............... 8W-10
Power Mirrors........................ 8W-62
WJ8W-02 COMPONENT INDEX 8W - 02 - 1

Component Page
Power Outlet......................... 8W-41
Power Seats.......................... 8W-63
Power Windows....................... 8W-60
Powertrain Control Module.............. 8W-30
Radio............................... 8W-47
Rain Sensor.......................... 8W-49
Recirculation Door Motor/Actuator........ 8W-42
Red Brake Warning Indicator Switch....... 8W-35
Remote Keyless Module................. 8W-39
Remote Radio Switches................. 8W-47
Splices.............................. 8W-10
Seat Belt Switch...................... 8W-43
Seat Module.......................... 8W-63
Sentry Key Immobilizer Module.......... 8W-39
Shifter Assembly...................... 8W-31
Side Impact Sensors................... 8W-43
Side Marker Lamps.................... 8W-50
Side Repeater Lamps................... 8W-52
Siren............................... 8W-49
Speakers............................ 8W-47Component Page
Speed Control Switches................. 8W-33
Sunroof............................. 8W-64
Temperature Valve Actuator............. 8W-42
Throttle Position Sensor................ 8W-30
Trailer Tow.......................... 8W-54
Transfer Case Position Sensor............ 8W-31
Transmission......................... 8W-31
Turn Signal Lamps.................... 8W-52
Underhood Lamp...................... 8W-44
Vehicle Information Center.............. 8W-49
Viscous/Cabin Heater................... 8W-30
Visor/Vanity Lamps.................... 8W-44
Washer Fluid Level Switch.............. 8W-53
Wastegate Solenoid.................... 8W-30
Water In Fuel Sensor................... 8W-30
Wheel Speed Sensors................... 8W-35
Window Defogger...................... 8W-48
Wiper High/Low Relay.................. 8W-53
Wiper Motor.......................... 8W-53
Washer Pump......................... 8W-5
8W - 02 - 2 8W-02 COMPONENT INDEXWJ

8W-10 POWER DISTRIBUTION
Component Page
A/C Compressor Clutch................. 8W-10-32
A/C Compressor Clutch Relay . . . 8W-10-13, 14, 25, 26, 32
Accessory Delay Relay.................. 8W-10-24
Auto Shut Down Relay....... 8W-10-11, 14, 19, 20, 25
Battery.......................... 8W-10-11, 12
Blower Motor................... 8W-10-11, 12, 15
Blower Motor Controller............ 8W-10-11, 12, 15
Body Control Module................ 8W-10-27, 29
Camshaft Position Sensor................ 8W-10-26
Capacitor........................ 8W-10-19, 20
Capacitor No. 1....................... 8W-10-22
Capacitor No. 2....................... 8W-10-22
Cigar Lighter Relay.................... 8W-10-15
Circuit Breaker No. 1 (JB)............... 8W-10-29
Circuit Breaker No. 2 (JB)............... 8W-10-24
Coil On Plug No. 1.................... 8W-10-22
Coil On Plug No. 2.................... 8W-10-22
Coil On Plug No. 3.................... 8W-10-22
Coil On Plug No. 4.................... 8W-10-22
Coil On Plug No. 5.................... 8W-10-22
Coil On Plug No. 6.................... 8W-10-22
Coil On Plug No. 7.................... 8W-10-22
Coil On Plug No. 8.................... 8W-10-22
Coil Rail......................... 8W-10-19, 20
Controller Antilock
Brake............ 8W-10-11, 12, 13, 14, 17, 18, 32
Crankcase Heater..................... 8W-10-26
Driver Door Module.................... 8W-10-30
EGR Solenoid........................ 8W-10-26
Engine Control Module............ 8W-10-14, 26, 31
Engine Starter Motor................... 8W-10-27
Engine Starter Motor Relay.............. 8W-10-27
Fog Lamp Relay...................... 8W-10-24
Fuel Injector No. 1..................... 8W-10-21
Fuel Injector No. 2..................... 8W-10-21
Fuel Injector No. 3..................... 8W-10-21
Fuel Injector No. 4..................... 8W-10-21
Fuel Injector No. 5..................... 8W-10-21
Fuel Injector No. 6..................... 8W-10-21
Fuel Injector No. 7..................... 8W-10-21
Fuel Injector No. 8..................... 8W-10-21
Fuel Pressure Solenoid.................. 8W-10-26
Fuel Pump Module.................... 8W-10-32
Fuel Pump Relay................... 8W-10-13, 32
Fuse 1........................ 8W-10-11, 12, 15
Fuse 2........................ 8W-10-11, 12, 15
Fuse 3........................ 8W-10-11, 12, 16
Fuse 4..................... 8W-10-11, 12, 17, 18
Fuse 5........................ 8W-10-11, 17, 30
Fuse 6................ 8W-10-11, 12, 16, 18, 19, 20
Fuse 7..................... 8W-10-11, 12, 24, 30
Fuse 8..................... 8W-10-11, 12, 27, 30
Fuse 9............................. 8W-10-30
Fuse 10............................ 8W-10-30
Fuse 11....................... 8W-10-12, 15, 18
Fuse 12.................. 8W-10-11, 12, 14, 29, 30
Fuse 13....................... 8W-10-12, 14, 25
Fuse 14.................. 8W-10-11, 13, 14, 16, 27
Fuse 15.................. 8W-10-11, 13, 14, 16, 30
Fuse 16.................. 8W-10-16, 19, 20, 23, 25
Component Page
Fuse 17............................ 8W-10-16
Fuse 18.................... 8W-10-13, 14, 30, 31
Fuse 20............................ 8W-10-28
Fuse 21.................... 8W-10-13, 14, 29, 32
Fuse 22....................... 8W-10-14, 29, 31
Fuse 23....................... 8W-10-14, 24, 25
Fuse 24....................... 8W-10-13, 24, 32
Fuse 25.................... 8W-10-13, 14, 24, 32
Fuse 26.................... 8W-10-15, 19, 20, 25
Fuse 27.................... 8W-10-13, 14, 24, 31
Fuse 28.......................... 8W-10-17, 29
Fuse 29............................ 8W-10-29
Fuse 30............................ 8W-10-29
Fuse 31............................ 8W-10-28
Fuse 32............................ 8W-10-29
Fuse 33............................ 8W-10-28
Fusible Link...................... 8W-10-11, 12
G200.............................. 8W-10-27
Generator...................... 8W-10-11, 12, 26
Glow Plug No. 1...................... 8W-10-18
Glow Plug No. 2...................... 8W-10-18
Glow Plug No. 3...................... 8W-10-18
Glow Plug No. 4...................... 8W-10-18
Glow Plug No. 5...................... 8W-10-18
Glow Plug Relay No. 1............. 8W-10-12, 18, 26
Glow Plug Relay No. 2............. 8W-10-12, 18, 26
High Beam Relay..................... 8W-10-16
Horn No. 1.......................... 8W-10-31
Horn No. 2.......................... 8W-10-31
Horn Relay..................... 8W-10-13, 14, 31
Hydraulic Cooling Module........ 8W-10-19, 20, 23, 26
Ignition Switch............. 8W-10-11, 14, 27, 28, 29
Intake Port Swirl Actuator............... 8W-10-26
Junction Block............. 8W-10-11, 12, 13, 14, 15,
16, 24, 28, 29, 30
Low Beam Relay...................... 8W-10-16
Low Beam/Daytime Running Lamp Relay.... 8W-10-16
Mass Air Flow Sensor.................. 8W-10-26
Oxygen Sensor 1/1 Upstream........... 8W-10-19, 20
Oxygen Sensor 1/2 Downstream......... 8W-10-19, 20
Oxygen Sensor 1/2 Downstream........... 8W-10-23
Oxygen Sensor 2/2 Downstream........... 8W-10-23
Oxygen Sensor Downstream Relay.... 8W-10-19, 20, 23
Park Lamp Relay..................... 8W-10-16
Passenger Door Module................. 8W-10-30
Power Distribution Center...... 8W-10-2, 3, 11, 12, 13,
14, 15, 16, 17, 18, 19, 20,
24, 25, 27, 30, 31, 32
Powertrain Control Module......... 8W-10-13, 19, 20
Rear Power Outlet............. 8W-10-13, 14, 24, 31
Rear Window Defogger.................. 8W-10-15
Rear Window Defogger Relay............. 8W-10-15
Trailer Tow Circuit Breaker.............. 8W-10-15
Transmission Control Module........... 8W-10-11, 17
Transmission Control Relay............ 8W-10-11, 17
Transmission Solenoid.................. 8W-10-17
Transmission Solenoid/TRS Assembly....... 8W-10-17
Viscous/Cabin Heater Relay......... 8W-10-14, 25, 26
Wastegate Solenoid.................... 8W-10-26
Water In Fuel Sensor................... 8W-10-26
WJ8W-10 POWER DISTRIBUTION 8W - 10 - 1