2003 JEEP GRAND CHEROKEE no start

(9) Install the six plastic nuts that secure the cowl
grille cover to the studs on the cowl top panel near
the base of the windshield. These nuts are to be
installed by pushing them onto the studs in the fol-
lowing sequence:
(a) First, install the short nuts to the third stud
from the right, then the second stud from the left.
(b) Next, install long nuts to the right outboard
stud, then the left outboard stud.
(c) Finally, install the two remaining long nuts
to the third stud from the left, then the second
stud from the right.
(10) Starting at the ends and working toward the
center, push the hood to plenum seal onto the for-
ward flanges of the cowl grille cover and the plenum
panel.
(11) Close and latch the hood.
(12) Reinstall the wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT WIPER ARMS -
INSTALLATION).
(13) Reconnect the battery negative cable.
RAIN SENSOR MODULE
DESCRIPTION
The Rain Sensor Module (RSM) is the primary
component of the automatic wiper system (Fig. 14).
The RSM is located on the inside of the windshield,
between the rear view mirror mounting button and
the windshield header and is concealed behind a
molded plastic trim cover that snaps over the modulehousing. The triangular-shaped molded black plastic
housing of the RSM has a rectangular opening
located on the upper end of the housing for the mod-
ule connector receptacle, which contains four termi-
nal pins. These terminal pins connect the rain sensor
to the vehicle electrical system through a dedicated
take out and connector of the overhead wire harness
that extends from above the headliner. Five openings
on the windshield side of the RSM housing are fitted
with eight convex clear plastic lenses. A metal spring
clip on each side of the housing near the bottom
secures the RSM to a plastic mounting bracket that
is bonded to the windshield glass. Concealed within
the RSM housing is the electronic circuitry of the
module, which includes four InfraRed (IR) diodes,
two photocells, and a microprocessor.
The RSM software is Flash compatible, which
means it can be reprogrammed using Flash repro-
gramming procedures. However, if any of the hard-
ware of the RSM is damaged or faulty, the entire
module must be replaced. The RSM bracket is ser-
viced as a unit with the windshield glass. If the
bracket is faulty, damaged, or separated from the
windshield glass, the windshield unit must be
replaced.
OPERATION
The microprocessor-based Rain Sensor Module
(RSM) senses moisture in the wipe pattern on the
outside of the windshield glass and sends wipe com-
mands to the Body Control Module (BCM). Four
InfraRed (IR) diodes within the RSM generate IR
light beams that are aimed by four of the convex
optical lenses near the base of the module through
the windshield glass. Four additional convex optical
lenses near the top of the RSM are focused on the IR
light beams on the outside of the windshield glass
and allow the two photocells within the module to
sense changes in the intensity of these IR light
beams. When sufficient moisture accumulates within
the wipe pattern of the windshield glass, the RSM
detects a change in the monitored IR light beam
intensity.
The internal programming of the RSM then sends
the appropriate electronic wipe command messages
to the BCM over the Programmable Communications
Interface (PCI) data bus. The BCM responds by acti-
vating or deactivating the front wiper system. The
BCM also sends electronic sensitivity level messages
to the RSM over the PCI data bus based upon the
driver-selected sensitivity setting of the control knob
on the control stalk of the right (wiper) multi-func-
tion switch. The higher the selected sensitivity set-
ting the more sensitive the RSM is to the
accumulated moisture on the windshield glass, and
Fig. 14 Rain Sensor Module
1 - SPRING CLIP (2)
2 - INFRARED LENS (4)
3 - HOUSING
4 - CONNECTOR RECEPTACLE
5 - PHOTOCELL LENS (4)
8R - 18 FRONT WIPERS/WASHERSWJ
FRONT WIPER MODULE (Continued)

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION....... 8W-01-1
COMPONENT INDEX.................. 8W-02-1
POWER DISTRIBUTION............... 8W-10-1
JUNCTION BLOCK.................... 8W-12-1
GROUND DISTRIBUTION.............. 8W-15-1
BUS COMMUNICATIONS.............. 8W-18-1
CHARGING SYSTEM.................. 8W-20-1
STARTING SYSTEM.................. 8W-21-1
FUEL/IGNITION SYSTEM.............. 8W-30-1
TRANSMISSION CONTROL SYSTEM..... 8W-31-1
VEHICLE SPEED CONTROL............ 8W-33-1
ANTILOCK BRAKES................... 8W-35-1
VEHICLE THEFT SECURITY SYSTEM..... 8W-39-1
INSTRUMENT CLUSTER............... 8W-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . . 8W-41-1
AIR CONDITIONING-HEATER........... 8W-42-1
AIRBAG SYSTEM.................... 8W-43-1
INTERIOR LIGHTING.................. 8W-44-1
BODY CONTROL MODULE............. 8W-45-1AUDIO SYSTEM..................... 8W-47-1
REAR WINDOW DEFOGGER............ 8W-48-1
OVERHEAD CONSOLE................. 8W-49-1
FRONT LIGHTING.................... 8W-50-1
REAR LIGHTING..................... 8W-51-1
TURN SIGNALS...................... 8W-52-1
WIPERS............................ 8W-53-1
TRAILER TOW....................... 8W-54-1
POWER WINDOWS................... 8W-60-1
POWER DOOR LOCKS................ 8W-61-1
POWER MIRRORS................... 8W-62-1
POWER SEATS...................... 8W-63-1
POWER SUNROOF................... 8W-64-1
SPLICE INFORMATION................ 8W-70-1
CONNECTOR PIN-OUT................ 8W-80-1
CONNECTOR/GROUND/SPLICE
LOCATION........................ 8W-91-1
POWER DISTRIBUTION............... 8W-97-1 WJWIRING 8W - 1

DESCRIPTION - CIRCUIT FUNCTIONS
All circuits in the diagrams use an alpha/numeric
code to identify the wire and it's function. To identify
which circuit code applies to a system, refer to the
Circuit Identification Code Chart. This chart shows
the main circuits only and does not show the second-
ary codes that may apply to some models.
CIRCUIT IDENTIFICATION CODE CHART
CIRCUIT FUNCTION
A BATTERY FEED
B BRAKE CONTROLS
C CLIMATE CONTROLS
D DIAGNOSTIC CIRCUITS
E DIMMING ILLUMINATION
CIRCUITS
F FUSED CIRCUITS
G MONITORING CIRCUITS
(GAUGES)
H OPEN
I NOT USED
J OPEN
K POWERTRAIN CONTROL
MODULE
L EXTERIOR LIGHTING
M INTERIOR LIGHTING
N NOT USED
O NOT USED
P POWER OPTION (BATTERY
FEED)
Q POWER OPTIONS (IGNITION
FEED)
R PASSIVE RESTRAINT
S SUSPENSION/STEERING
T TRANSMISSION/TRANSAXLE/
TRANSFER CASE
U OPEN
V SPEED CONTROL, WIPER/
WASHER
W OPEN
X AUDIO SYSTEMS
Y OPEN
Z GROUNDS
DESCRIPTION - SECTION IDENTIFICATION AND
INFORMATION
The wiring diagrams are grouped into individual
sections. If a component is most likely found in a par-
ticular group, it will be shown complete (all wires,
connectors, and pins) within that group. For exam-
ple, the Auto Shutdown Relay is most likely to be
found in Group 30, so it is shown there complete. It
can, however, be shown partially in another group if
it contains some associated wiring.
Splice diagrams in Section 8W-70 show the entire
splice and provide references to other sections the
splices serves. Section 8W-70 only contains splice dia-
grams that are not shown in their entirety some-
where else in the wiring diagrams.
Section 8W-80 shows each connector and the cir-
cuits involved with that connector. The connectors
are identified using the name/number on the dia-
gram pages.
WIRING SECTION CHART
GROUP TOPIC
8W-01 thru
8W-09General information and Diagram
Overview
8W-10 thru
8W-19Main Sources of Power and
Vehicle Grounding
8W-20 thru
8W-29Starting and Charging
8W-30 thru
8W-39Powertrain/Drivetrain Systems
8W-40 thru
8W-49Body Electrical items and A/C
8W-50 thru
8W-59Exterior Lighting, Wipers and
Trailer Tow
8W-60 thru
8W-69Power Accessories
8W-70 Splice Information
8W-80 Connector Pin Outs
8W-91 Connector, Ground and Splice
Locations
8W - 01 - 6 8W-01 WIRING DIAGRAM INFORMATIONWJ
WIRING DIAGRAM INFORMATION (Continued)

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)

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

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

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