Brake light fuse JEEP GRAND CHEROKEE 2003 WJ / 2.G Workshop Manual

(5) Connect the two instrument panel wire harness
connectors to the BCM.
(6) Reinstall the instrument panel fuse cover to
the bottom of the BCM and JB unit. (Refer to 8 -
ELECTRICAL/POWER DISTRIBUTION/FUSE
COVER - INSTALLATION).
(7) Connect the battery negative cable.
COMMUNICATION
DESCRIPTION
The Programmable Communication Interface (PCI)
data bus system is a single wire multiplex system
used for vehicle communications. Multiplexing is a
system that enables the transmission of several mes-
sages over a single channel or circuit.
Many of the control modules in a vehicle require
information from the same sensing device. Multiplex-
ing reduces wire harness complexity, sensor current
loads and controller hardware because each sensing
device is connected to only one controller, which
reads and distributes the sensor information to the
other controllers over the data bus. Also, because
each controller on the data bus can access the con-
troller sensor inputs to every other controller on the
data bus, more function and feature capabilities are
possible.
A multiplex system allows the information flowing
between controllers to be monitored using a diagnos-
tic scan tool. This system allows a control module to
broadcast message data out onto the bus where all
other control modules can read the messages that are
being sent. When a module reads a message on the
data bus that it requires, it relays that message to
its microprocessor. Each module ignores the mes-
sages on the data bus that it dosen't recognize.
OPERATION
Data exchange between modules is achieved by
serial transmission of encoded data over a single wire
broadcast network. The PCI data bus messages are
carried over the bus in the form of Variable Pulse
Width Modulated (VPWM) signals. The PCI data bus
speed is an average 10.4 Kilo-bits per second (Kbps).
The voltage network used to transmit messages
requires biasing and termination. Each module on
the PCI data bus system provides its own biasing
and termination. Each module (also referred to as a
node) terminates the bus through a terminating
resistor and a terminating capacitor. The Powertrain
Control Module (PCM) is the only dominant node for
the PCI data bus system.
The PCI bus uses low and high voltage levels to
generate signals. The voltage on the buss varies
between zero and seven and one-half volts. The lowand high voltage levels are generated by means of
variable-pulse width modulation to form signals of
varying length.
When a module is transmitting on the bus, it is
reading the bus at the same time to ensure message
integrity.
Each module is capable of transmitting and receiv-
ing data simultaneously.
The PCI data bus can be monitored using the
DRBIIItscan tool. It is possible for the bus to pass
all DRBIIIttests and still be faulty if the voltage
parameters are all within the specified range and
false messages are being sent.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system (Fig. 4).
OPERATION
The CAB voltage is supplied by the ignition switch
in the RUN position. The CAB contains dual micro-
processors. A logic block in each microprocessor
receives identical sensor signals. These signals are
processed and compared simultaneously. The CAB
contains a self check program that illuminates the
ABS warning light when a system fault is detected.
Faults are stored in a diagnostic program memory
and are accessible with the DRBIIItscan tool. ABS
faults remain in memory until cleared, or until after
the vehicle is started approximately 50 times. Stored
Fig. 4 Controller Antilock Brakes
1 - HCU
2 - MOTOR
3 - CAB
8E - 6 ELECTRONIC CONTROL MODULESWJ
BODY CONTROL MODULE (Continued)

The VFD is diagnosed using the EMIC self-diag-
nostic actuator test. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND
TESTING). Proper testing of the PCI data bus and
the data bus message inputs to the EMIC that con-
trol the VFD functions requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation. Specific operation details for the odometer
and trip odometer functions of the VFD may be found
elsewhere in this service information.
INDICATORS
Indicators are located in various positions within
the EMIC and are all connected to the EMIC circuit
board. The turn signal indicators are hard wired. The
brake indicator is controlled by PCI data bus mes-
sages from the Controller Antilock Brake (CAB) as
well as by hard wired park brake switch and brake
fluid level switch inputs to the EMIC. The Malfunc-
tion Indicator Lamp (MIL) is normally controlled by
PCI data bus messages from the Powertrain Control
Module (PCM); however, if the EMIC loses PCI data
bus communication, the EMIC circuitry will automat-
ically turn the MIL on until PCI data bus communi-
cation is restored. The EMIC uses PCI data bus
messages from the Airbag Control Module (ACM), the
BCM, the PCM, the CAB, the Sentry Key Immobi-
lizer Module (SKIM), and the Transmission Control
Module (TCM) to control all of the remaining indica-
tors.
The various indicators are controlled by different
strategies; some receive fused ignition switch output
from the EMIC circuitry and have a switched ground,
others are grounded through the EMIC circuitry and
have a switched battery feed, while still others are
completely controlled by the EMIC microprocessor
based upon various hard wired and electronic mes-
sage inputs. Some indicators are illuminated at a
fixed intensity, while the illumination intensity of
others is synchronized with that of the EMIC general
illumination lamps.
The hard wired indicators are diagnosed using con-
ventional diagnostic methods. The EMIC and PCI
bus message controlled indicators are diagnosed
using the EMIC self-diagnostic actuator test. (Refer
to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING). Proper testing of the
PCI data bus and the electronic data bus message
inputs to the EMIC that control each indicator
require the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information. Specific details of
the operation for each indicator may be found else-
where in this service information.CLUSTER ILLUMINATION
Two types of general cluster illumination are avail-
able in this model. Base versions of the EMIC have
several incandescent illumination lamps, while pre-
mium versions of the EMIC have a single electro-lu-
minescent lamp. Both types of lamps provide cluster
back lighting whenever the exterior lighting is
turned On with the control knob on the left (lighting)
multi-function switch control stalk. The illumination
intensity of these lamps is adjusted by the EMIC
microprocessor based upon electronic dimming level
messages received from the Body Control Module
(BCM) over the PCI data bus. The BCM provides
electronic dimming level messages to the EMIC
based upon internal programming and inputs it
receives when the control ring on the left (lighting)
multi-function switch control stalk is rotated (down
to dim, up to brighten) to one of six available minor
detent positions.
The incandescent illumination lamps receive bat-
tery current at all times, while the ground for these
lamps is controlled by a 12-volt Pulse Width Modu-
lated (PWM) output of the EMIC electronic circuitry.
The illumination intensity of these bulbs and of the
vacuum-fluorescent electronic display are controlled
by the instrument cluster microprocessor based upon
dimming level messages received from the Body Con-
trol Module (BCM) over the PCI data bus. The BCM
uses inputs from the headlamp and panel dimmer
switches within the left (lighting) multi-function
switch control stalk and internal programming to
decide what dimming level message is required. The
BCM then sends the proper dimming level messages
to the EMIC over the PCI data bus.
The electro-luminescent lamp unit consists of lay-
ers of phosphor, carbon, idium tin oxide, and dielec-
tric applied by a silk-screen process between two
polyester membranes and includes a short pigtail
wire and connector. The lamp pigtail wire is con-
nected to a small connector receptacle on the EMIC
circuit board through a small clearance hole in the
cluster housing rear cover. The EMIC electronic cir-
cuitry also uses a PWM strategy to control the illu-
mination intensity of this lamp; however, the EMIC
powers this lamp with an Alternating Current (AC)
rated at 80 volts rms (root mean squared) and 415
Hertz, which excites the phosphor particles causing
them to luminesce.
The BCM also has several hard wired panel lamp
driver outputs and sends the proper panel lamps
dimming level messages over the PCI data bus to
coordinate the illumination intensity of all of the
instrument panel lighting and the VFDs of other
electronic modules on the PCI data bus. Vehicles
equipped with the Auto Headlamps option have an
automatic parade mode. In this mode, the BCM uses
8J - 6 INSTRUMENT CLUSTERWJ
INSTRUMENT CLUSTER (Continued)

tor will be turned on for the duration of the test to
confirm the functionality of the bulb and the cluster
control circuitry.
²ABS Diagnostic Test- The ABS indicator is
blinked on and off based upon lamp-on and lamp-off
messages from the CAB during the performance of
the ABS diagnostic tests.
The CAB continually monitors the ABS circuits
and sensors to decide whether the system is in good
operating condition. The CAB then sends the proper
ABS indicator lamp-on or lamp-off messages to the
instrument cluster. If the ABS indicator fails to light
during the bulb test, replace the bulb with a known
good unit. If the CAB sends an ABS indicator
lamp-on message after the bulb test, it indicates that
the CAB has detected a system malfunction and/or
that the ABS system has become inoperative. The
CAB will store a Diagnostic Trouble Code (DTC) for
any malfunction it detects. Each time the ABS indi-
cator fails to illuminate due to an open or short in
the cluster ABS indicator circuit or bulb, the cluster
sends a message notifying the CAB of the condition,
then the instrument cluster and the CAB will each
store a DTC. For proper diagnosis of the anti-lock
brake system, the CAB, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the ABS indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
AIRBAG INDICATOR
DESCRIPTION
An airbag indicator is standard equipment on all
instrument clusters. However, the instrument cluster
is programmed to automatically enable this indicator
only on vehicles equipped with the airbag system,
which is not available in some markets. The airbag
indicator is located on the upper edge of the instru-
ment cluster, between the speedometer and the
tachometer. The airbag indicator consists of the
words ªAIR BAGº imprinted on a red lens. The lens
is located behind a cutout in the opaque layer of the
instrument cluster overlay. The dark outer layer of
the overlay prevents the indicator from being clearly
visible when it is not illuminated. The ªAIR BAGº
text appears silhouetted against a red field through
the translucent outer layer of the overlay when the
indicator is illuminated from behind by a Light Emit-
ting Diode (LED), which is soldered onto the instru-
ment cluster electronic circuit board. The airbag
indicator lens is serviced as a unit with the instru-
ment cluster lens, hood and mask unit.
OPERATION
The airbag indicator gives an indication to the
vehicle operator when the airbag system is faulty or
inoperative. The airbag indicator is controlled by a
transistor on the instrument cluster circuit board
based upon cluster programming and electronic mes-
sages received by the cluster from the Airbag Control
Module (ACM) over the Programmable Communica-
tions Interface (PCI) data bus. The airbag indicator
Light Emitting Diode (LED) is completely controlled
by the instrument cluster logic circuit, and that logic
will only allow this indicator to operate when the
instrument cluster receives a battery current input
on the fused ignition switch output (run-start) cir-
cuit. Therefore, the indicator will always be off when
the ignition switch is in any position except On or
Start. The LED only illuminates when it is switched
to ground by the instrument cluster transistor. The
instrument cluster will turn on the airbag indicator
for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the ACM sends an elec-
tronic airbag indicator lamp-on message to the clus-
ter which will illuminate the airbag indicator for
about six seconds as a bulb test. The entire six sec-
ond bulb test is a function of the ACM.
²Airbag Indicator Lamp-On Message- Each
time the cluster receives an airbag indicator lamp-on
message from the ACM, the airbag indicator will be
illuminated. The indicator remains illuminated for
about twelve seconds or until the cluster receives an
airbag indicator lamp-off message from the ACM,
whichever is longer.
²Communication Error- If the cluster receives
no airbag indicator lamp-on or lamp-off messages for
six consecutive seconds, the airbag indicator is illu-
minated. The indicator remains illuminated until the
cluster receives a single valid airbag indicator lamp-
off message from the ACM.
²Actuator Test- Each time the cluster is put
through the actuator test, the airbag indicator will be
turned on, then off again during the bulb check por-
tion of the test to confirm the functionality of the
LED and the cluster control circuitry. The actuator
test illumination of the airbag indicator is also a
function of the ACM.
The ACM continually monitors the airbag system
circuits and sensors to decide whether the system is
in good operating condition. The ACM then sends the
proper airbag indicator lamp-on or lamp-off messages
to the instrument cluster. If the ACM sends an air-
bag indicator lamp-on message after the bulb test, it
indicates that the ACM has detected a system mal-
function. Such a malfunction could mean that the
airbags may not deploy when required, or may
deploy when not required. The ACM will store a
8J - 14 INSTRUMENT CLUSTERWJ
ABS INDICATOR (Continued)

Diagnostic Trouble Code (DTC) for any malfunction it
detects. Each time the airbag indicator fails to illu-
minate due to an open or short in the cluster airbag
indicator circuit, the cluster sends a message notify-
ing the ACM of the condition, then the instrument
cluster and the ACM will each store a DTC. For
proper diagnosis of the airbag system, the ACM, the
PCI data bus, or the electronic message inputs to the
instrument cluster that control the airbag indicator,
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.
BRAKE/PARK BRAKE
INDICATOR
DESCRIPTION
A brake indicator is standard equipment on all
instrument clusters. The brake indicator is located
near the left edge of the instrument cluster, to the
left of the tachometer. There are two versions of the
brake indicator. The version used depends upon the
market for which the vehicle is manufactured. The
version of the brake indicator used for vehicles man-
ufactured for the United States consists of the word
ªBRAKEº imprinted on a red lens. The Rest-Of-World
(ROW) market version of this indicator has two
International Control and Display Symbol icons
imprinted on the red lens; one is the icon for ªBrake
Failureº, and the other is the icon for ªParking
Brakeº. In either case, the lens is located behind a
cutout in the opaque layer of the instrument cluster
overlay. The dark outer layer of the overlay prevents
the indicator from being clearly visible when it is not
illuminated. The ªBRAKEº text or the two icons
appear silhouetted against a red field through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by a Light Emitting
Diode (LED), which is soldered onto the instrument
cluster electronic circuit board. The brake indicator
lens is serviced as a unit with the instrument cluster
lens, hood and mask unit.
OPERATION
The brake indicator gives an indication to the vehi-
cle operator when the parking brake is applied, when
the fluid level of the brake hydraulic system is low,
or if there are certain malfunctions of the Anti-lock
Brake System (ABS). This indicator is controlled by a
transistor on the instrument cluster electronic circuit
board based upon cluster programming, electronic
messages received by the cluster from the Controller
Anti-lock Brake (CAB) over the Programmable Com-
munications Interface (PCI) data bus, and a hard
wired input to the cluster from the park brake
switch. The brake indicator Light Emitting Diode(LED) is completely controlled by the instrument
cluster logic circuit, and that logic will only allow
this indicator to operate when the instrument cluster
receives a battery current input on the fused ignition
switch output (run-start) circuit. Therefore, the indi-
cator will always be off when the ignition switch is in
any position except On or Start. The LED only illu-
minates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the brake indicator for the following rea-
sons:
²Bulb Test- Each time the ignition switch is
turned to the On position the brake indicator is illu-
minated by the instrument cluster for about three
seconds as a bulb test.
²Brake Indicator Lamp-On Message- Each
time the cluster receives a brake indicator lamp-on
message from the CAB, the brake indicator will be
illuminated. The indicator remains illuminated until
the cluster receives a brake indicator lamp-off mes-
sage from the CAB.
²Park Brake Switch Input- Each time the
cluster logic circuit detects ground on the park brake
switch sense circuit (park brake switch closed = park
brake applied or not fully released) the brake indica-
tor is illuminated. The indicator remains illuminated
until the park brake switch sense input to the cluster
is an open circuit (park brake switch open = park
brake fully released), or until the ignition switch is
turned to the Off position, whichever occurs first.
²Communication Error- If the cluster receives
no brake indicator lamp-on or lamp-off messages
from the CAB for six consecutive seconds, the brake
indicator is illuminated. The indicator remains illu-
minated until the cluster receives a single valid
brake indicator lamp-off message from the CAB.
²Actuator Test- Each time the cluster is put
through the actuator test, the brake indicator will be
turned on for the duration of the test to confirm the
functionality of the LED and the cluster control cir-
cuitry.
The park brake switch on the park brake pedal
mechanism provides a hard wired ground input to
the instrument cluster circuitry through the red
brake warning indicator driver circuit whenever the
park brake is applied or not fully released. The CAB
continually monitors the input from the brake fluid
level switch and the circuits of the anti-lock brake
system, then sends the proper brake indicator
lamp-on or lamp-off messages to the instrument clus-
ter. If the CAB sends a brake indicator lamp-on mes-
sage after the bulb test, it indicates that the CAB
has detected a brake hydraulic system malfunction
and/or that the ABS system has become inoperative.
The CAB will store a Diagnostic Trouble Code (DTC)
for any malfunction it detects.
WJINSTRUMENT CLUSTER 8J - 15
AIRBAG INDICATOR (Continued)

OPERATION
The speedometer gives an indication to the vehicle
operator of the vehicle road speed. This gauge is con-
trolled by the instrument cluster electronic circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus. The
speedometer is an air core magnetic unit that
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (run-start) circuit whenever the igni-
tion switch is in the On or Start positions. The clus-
ter is programmed to move the gauge needle back to
the low end of the scale after the ignition switch is
turned to the Off position. The instrument cluster
circuitry controls the gauge needle position and pro-
vides the following features:
²Vehicle Speed Message- Each time the clus-
ter receives a vehicle speed message from the PCM it
will calculate the correct vehicle speed reading and
position the gauge needle at that speed position on
the gauge scale. The cluster will receive a new vehi-
cle speed message and reposition the gauge pointer
accordingly about every 86 milliseconds. The gauge
needle will continue to be positioned at the actual
vehicle speed position on the gauge scale until the
ignition switch is turned to the Off position.
²Communication Error- If the cluster fails to
receive a speedometer message, it will hold the gauge
needle at the last indication for about six seconds, or
until the ignition switch is turned to the Off position,
whichever occurs first. If a new speed message is not
received after about six seconds, the gauge needle
will return to the far left (low) end of the scale.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept across the entire gauge scale and back in order
to confirm the functionality of the gauge and the
cluster control circuitry.
The PCM continually monitors the vehicle speed
information received from the Controller Anti-lock
Brake (CAB) to determine the vehicle road speed,
then sends the proper vehicle speed messages to the
instrument cluster. For further diagnosis of the
speedometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the CAB, the PCM, the
PCI data bus, or the electronic message inputs to the
instrument cluster that control the speedometer, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
TACHOMETER
DESCRIPTION
A tachometer is standard equipment on all instru-
ment clusters. The tachometer is located to the left of
the speedometer in the instrument cluster. The
tachometer consists of a movable gauge needle or
pointer controlled by the instrument cluster circuitry,
and a fixed 255 degree scale on the gauge dial face
that reads left-to-right from 0 to 7 for gasoline
engines, or from 0 to 6 for diesel engines. The text ªX
1000º (base cluster) or ªRPM X 1000º (premium clus-
ter) imprinted on the cluster overlay directly below
the hub of the tachometer needle identifies that each
number on the tachometer scale is to be multiplied
by 1000 rpm. The gasoline engine tachometer has a
red zone beginning at 5800 RPM, while the red zone
for the diesel engine tachometer begins at 4200 RPM.
The tachometer in the premium version cluster for
certain engine and market applications also includes
red text located in the center of the gauge dial face
just above the hub of the tachometer needle that
specifies a special fuel requirement.
The tachometer graphics are either white, gray
and orange against a black gauge dial face (base
cluster) or black, gray and red against a taupe gauge
dial face (premium cluster), making them clearly vis-
ible within the instrument cluster in daylight. When
illuminated from behind by the panel lamps dimmer
controlled cluster illumination lighting with the exte-
rior lamps turned On, the base cluster white gauge
graphics appear blue-green and the orange graphics
still appear orange, while the premium cluster taupe
gauge dial face appears blue-green with the black
graphics silhouetted against the illuminated back-
ground and the red graphics still appear red. The
gray gauge graphics for both versions of the cluster
are not illuminated. The orange gauge needle in the
base cluster gauge is internally illuminated, while
the black gauge needle in the premium cluster gauge
is not.
Base cluster gauge illumination is provided by
replaceable incandescent bulb and bulb holder units
located on the instrument cluster electronic circuit
board. Premium cluster gauge illumination is pro-
vided by an integral electro-luminescent lamp that is
serviced as a unit with the instrument cluster. The
tachometer is serviced as a unit with the instrument
cluster.
OPERATION
The tachometer gives an indication to the vehicle
operator of the engine speed. This gauge is controlled
by the instrument cluster electronic circuit board
based upon cluster programming and electronic mes-
sages received by the cluster from the Powertrain
WJINSTRUMENT CLUSTER 8J - 31
SPEEDOMETER (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS DO NOT
ILLUMINATE1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Electrical, Wiring
Information.
2. No Z1-ground at fog lamps. 2. Repair circuit ground. Refer to Electrical,
Wiring Information.
3. Faulty multifunction switch. 3. Refer to Electrical, Wiring Information.
4. Broken connector terminal or wire
splice in fog lamp circuit.4. Repair connector terminal or wire splice.
5. Defective or burned out bulb. 5. Replace bulb.
DAYTIME RUNNING LAMP
CONDITION POSSIBLE CAUSES CORRECTION
DAYTIME RUNNING LAMPS DO
NOT WORK1. Poor connection at DRL module. 1. Secure connector on DRL
module.
2. Parking brake engaged. 2. Disengage parking brake.
3. Parking brake circuit shorted to
ground.3. Check cluster telltale, refer to
Group 8W.
4. Headlamp circuit shorted to
ground.4. Refer to Group 8W.
5. Defective DRL relay. 5. Replace DRL relay.
6. Body controller not programed
with Canadian country code.6. Check country code.
7. DRL relay is missing. 7. Install DRL relay.
8. Blown fuse for DRL. 8. Replace fuse refer to Electrical,
Wiring Information.
Clicking or chattering when DRL is
on.1. Mechanical relay is installed in
the junction block.1. Ensure that the DRL relay is
installed in the proper socket in
junction block, and that no
mechanical relay exists in the low
beam socket.
DIAGNOSIS AND TESTING Ð HEADLAMP
WARNING: EYE PROTECTION SHOULD BE USED
WHEN SERVICING GLASS COMPONENTS. PER-
SONAL INJURY CAN RESULT.
CAUTION: Do not touch the glass of halogen bulbs
with fingers or other possibly oily surface, reduced
bulb life will result. Do not use bulbs other than
those indicated in the Bulb Application table. Dam-
age to lamp and/or Daytime Running Lamp Module
can result. Do not use fuses, circuit breakers or
relays having greater amperage value than indi-
cated on the fuse panel or in the Owners Manual.
Each vehicle is equipped with various lamp assem-
blies. A good power feed and ground are necessary forproper lighting operation. Grounding is provided by
the lamp socket when it comes in contact with the
metal body, or through a separate ground wire.
When changing lamp bulbs check the socket for
corrosion. If corrosion is present, clean it with a wire
brush and coat the inside of the socket lightly with
Mopar Multi-Purpose Grease or equivalent.
REMOVAL - BULB
(1) Remove the headlamp.
(2) Turn the bulb socket one quarter turn counter
clockwise.
(3) Remove the socket from lamp (Fig. 13).
(4) Remove the bulb from socket.
8L - 14 LAMPS/LIGHTING - EXTERIORWJ
HEADLAMP (Continued)

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)

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

8W-12 JUNCTION BLOCK
Component PageA/C Compressor Clutch Relay................8W-12-18
Accessory Delay Relay.....................8W-12-25
Adjustable Pedals Module..................8W-12-11
Airbag Control Module....................8W-12-25
Auto Shut Down Relay....................8W-12-18
Automatic Day/Night Mirror.................8W-12-23
Automatic Headlamp Light Sensor/VTSS LED......8W-12-15
Automatic Zone Control Module..........8W-12-15, 17, 22
Back-Up Lamp Relay.....................8W-12-22
Body Control Module . . . 8W-12-10, 12, 13, 15, 17, 20, 23, 24, 25,
26, 27, 28, 29, 30, 31, 35, 36
Brake Lamp Switch......................8W-12-24
Cargo Lamp......................8W-12-16, 24, 27
Cigar Lighter..........................8W-12-17
Cigar Lighter Relay....................8W-12-17, 26
Circuit Breaker No. 1...................8W-12-28, 29
Circuit Breaker No. 2......................8W-12-9
Clockspring...........................8W-12-31
Combination Flasher............8W-12-10, 22, 27, 32, 35
Controller Antilock Brake..................8W-12-21
Data Link Connector.....................8W-12-10
Driver Door Module......................8W-12-34
Driver Heated Seat Switch..................8W-12-22
Driver Lumbar Switch.....................8W-12-9
Driver Power Seat Switch...................8W-12-9
Electric Brake..........................8W-12-21
Engine Control Module....................8W-12-19
Engine Starter Motor Relay.................8W-12-26
EVAP/Purge Solenoid.....................8W-12-18
Fog Lamp Relay........................8W-12-24
Front Power Outlet......................8W-12-11
Front Wiper Motor....................8W-12-28, 29
Fuel Pump Relay........................8W-12-18
Fuse 2..............................8W-12-17
Fuse 3............................8W-12-10, 20
Fuse 4..............................8W-12-10
Fuse 5..............................8W-12-11
Fuse 6............................8W-12-12, 13
Fuse 7..............................8W-12-15
Fuse 8..............................8W-12-16
Fuse 9..............................8W-12-11
Fuse 10..............................8W-12-11
Fuse 11..............................8W-12-17
Fuse 12.......................8W-12-18, 19, 21, 34
Fuse 14..............................8W-12-20
Fuse 15.........................8W-12-11, 15, 20
Fuse 16..............................8W-12-10
Fuse 17..............................8W-12-10
Fuse 18...........................8W-12-21, 34
Fuse 19..............................8W-12-21
Fuse 20..............................8W-12-22
Fuse 21...........................8W-12-18, 19
Fuse 22..............................8W-12-23
Fuse 23..............................8W-12-24
Fuse 24..............................8W-12-24
Fuse 25..............................8W-12-25
Fuse 26..............................8W-12-17
Fuse 27..............................8W-12-36
Fuse 28..............................8W-12-26
Fuse 29..............................8W-12-26
Fuse 30..............................8W-12-26
Fuse 31..............................8W-12-26
Fuse 32..............................8W-12-25
Fuse 33..............................8W-12-25
G200...............................8W-12-35
Glove Box Lamp........................8W-12-16
Headlamp Leveling Switch...............8W-12-12, 13
High Beam Relay........................8W-12-10
Horn Relay...........................8W-12-31
Horn Switch...........................8W-12-31
Instrument Cluster..................8W-12-10, 23, 32
Intrusion Transceiver Module................8W-12-16
Junction Block.........8W-12-2, 3, 9, 10, 11, 12, 13, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24, 25,
26, 27, 28, 29, 30, 31, 32, 34, 35, 36Component PageLeft Courtesy Lamp......................8W-12-16
Left Door Handle Courtesy Lamp.........8W-12-16, 24, 30
Left Fog Lamp.........................8W-12-24
Left Front Park Lamp.....................8W-12-14
Left Front Park/Turn Signal Lamp...........8W-12-14, 33
Left Front Side Marker Lamp..............8W-12-14, 33
Left Front Turn Signal Lamp................8W-12-33
Left Headlamp Leveling Motor...............8W-12-14
Left High Beam Headlamp..................8W-12-10
Left Liftgate Ajar Switch...................8W-12-30
Left Low Beam Headlamp..................8W-12-20
Left Multi-Function Switch...............8W-12-10, 35
Left Rear Door Lock Motor/Ajar Switch..........8W-12-27
Left Rear Lamp Assembly...........8W-12-12, 13, 27, 36
Left Side Repeater Lamp...................8W-12-32
Left Visor/Vanity Lamp..................8W-12-16, 30
License Lamp No. 1....................8W-12-12, 13
License Lamp No. 2....................8W-12-12, 13
Liftgate Flip-Up Ajar Switch.................8W-12-30
Liftgate Flip-Up Push Button Switch...........8W-12-16
Liftgate Power Lock Motor..................8W-12-16
Low Beam Relay........................8W-12-20
Low Beam/Daytime Running Lamp Relay.........8W-12-20
Manual Temperature Control..............8W-12-17, 22
Overhead Map/Courtesy Lamp...........8W-12-16, 24, 30
Park Lamp Relay.....................8W-12-12, 13
Park/Neutral Position Switch................8W-12-22
Passenger Door Module....................8W-12-34
Passenger Heated Seat Switch...............8W-12-22
Passenger Lumbar Switch...................8W-12-9
Passenger Power Seat Switch.................8W-12-9
Power Amplifier.........................8W-12-11
Power Connector........................8W-12-11
Power Distribution Center....8W-12-10, 11, 15, 17, 20, 21, 34
Powertrain Control Module.................8W-12-18
Radio.............................8W-12-11, 26
Rain Sensor...........................8W-12-25
Rear Window Defogger....................8W-12-17
Rear Window Defogger Relay................8W-12-17
Rear Wiper Motor.....................8W-12-16, 30
Remote Keyless Module....................8W-12-15
Right Courtesy Lamp.....................8W-12-16
Right Door Handle Courtesy Lamp........8W-12-16, 24, 30
Right Fog Lamp........................8W-12-24
Right Front Park Lamp....................8W-12-14
Right Front Park/Turn Signal Lamp..........8W-12-14, 33
Right Front Side Marker Lamp.............8W-12-14, 33
Right Front Turn Signal Lamp...............8W-12-33
Right Headlamp Leveling Motor..............8W-12-14
Right High Beam Headlamp.................8W-12-10
Right Liftgate Ajar Switch..................8W-12-30
Right Low Beam Headlamp.................8W-12-20
Right Multi-Function Switch.................8W-12-26
Right Rear Lamp Assembly..........8W-12-12, 13, 32, 36
Right Side Repeater Lamp..................8W-12-32
Right Visor/Vanity Lamp.................8W-12-16, 30
Seat Module...........................8W-12-9
Sentry Key Immobilizer Module............8W-12-15, 23
Shifter Assembly......................8W-12-18, 19
Siren...............................8W-12-15
Sunroof Control Module....................8W-12-25
Temperature Valve Actuator.................8W-12-22
Trailer Tow Brake Lamp Relay...............8W-12-21
Trailer Tow Circuit Breaker.................8W-12-17
Trailer Tow Connector.....................8W-12-12
Trailer Tow Left Turn Relay.................8W-12-27
Trailer Tow Right Turn Relay................8W-12-32
Transmission Control Module..............8W-12-18, 26
Transmission Solenoid/TRS Assembly...........8W-12-22
Underhood Lamp........................8W-12-15
Vehicle Information Center...............8W-12-16, 23
Wiper High/Low Relay..................8W-12-28, 29
Wiper On/Off Relay....................8W-12-28, 29
WJ8W-12 JUNCTION BLOCK 8W - 12 - 1