Engine wiring JEEP GRAND CHEROKEE 2003 WJ / 2.G Owner's Guide

DIAGNOSIS AND TESTING - WIPER ON/OFF
RELAY
The wiper on/off relay (Fig. 29) is located in the
Power Distribution Center (PDC) in the engine com-
partment near the battery. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
(1) Remove the wiper on/off relay from the PDC.
(Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ON/OFF RELAY - REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRBIIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC) (Fig. 30).
(3) See the fuse and relay layout label affixed to
the underside of the PDC cover for wiper on/off relay
identification and location.
(4) Remove the wiper on/off relay by grasping it
firmly and pulling it straight out from the receptacle
in the PDC.
INSTALLATION
(1) See the fuse and relay layout label affixed to
the underside of the PDC cover for the proper wiper
on/off relay location (Fig. 30).
(2) Position the wiper on/off relay in the proper
receptacle in the PDC.
(3) Align the wiper on/off relay terminals with the
terminal cavities in the PDC receptacle.
(4) Push firmly and evenly on the top of the wiper
on/off relay until the terminals are fully seated in the
terminal cavities in the PDC receptacle.
(5) Reinstall the cover onto the PDC.
(6) Reconnect the battery negative cable.
Fig. 29 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
Fig. 30 Power Distribution Center
1 - RIGHT FENDER
2 - BATTERY
3 - POWER DISTRIBUTION CENTER
4 - COVER
8R - 32 FRONT WIPERS/WASHERSWJ
WIPER ON/OFF RELAY (Continued)

²Washer Reservoir- The rear washer system
shares a single reservoir with the front washer sys-
tem, but has its own dedicated washer pump/motor
and plumbing. The washer reservoir is concealed
between the left inner fender shield and the left
outer fender panel, behind the inner fender liner and
ahead of the left front wheel. The washer reservoir
filler neck is the only visible portion of the reservoir,
and it is accessed from the left front corner of the
engine compartment.
Features of the rear wiper and washer system
include the following:
²Continuous Wipe Mode- When the right
multi-function switch control sleeve is moved to the
On position, the rear wiper will be operated at a
fixed speed, continual wipe cycle until the switch
sleeve is moved to the Delay or Off positions, until
the ignition switch is turned to the Off position, or
until the liftgate flip-up glass is ajar.
²Intermittent Wipe Mode- When the right
multi-function switch control sleeve is moved to the
Delay position, the rear wiper will be operated in a
fixed interval, intermittent wipe cycle until the
switch sleeve is moved to the On or Off positions,
until the ignition switch is turned to the Off position,
until the liftgate flip-up glass is ajar, or until the
right multi-function switch control stalk is pushed
forward to activate the rear washer system. The
intermittent wipe mode delay time has a fixed delay
interval of about five to eight seconds between
sweeps.
²Washer Mode- When the right multi-function
switch control stalk is pushed forward to activate the
rear washer system, washer fluid will be dispensed
from the washer reservoir onto the liftgate glass
through the rear washer nozzle and the rear wiper
will operate in a fixed cycle (not intermittent) for as
long as the rear washer pump/motor unit remains
energized. When the control stalk is released from
the momentary Wash position, the wipe-after-wash
feature will continue to operate the rear wiper at a
fixed cycle for about three additional wiper sweeps
before returning to the previously selected mode.
Hard wired circuitry connects the rear wiper and
washer system components to the electrical system of
the vehicle. These hard wired circuits are integral to
several wire harnesses, which are routed throughout
the vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the rear wiper and
washer system components through the use of a com-
bination of soldered splices, splice block connectors,
and many different types of wire harness terminal
connectors and insulators. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repairprocedures, further details on wire harness routing
and retention, as well as pin-out and location views
for the various wire harness connectors, splices and
grounds.
OPERATION
The rear wiper and washer system is intended to
provide the vehicle operator with a convenient, safe,
and reliable means of maintaining visibility through
the liftgate glass. The various components of this sys-
tem are designed to convert electrical energy pro-
duced by the vehicle electrical system into the
mechanical action of the wiper blade to wipe the out-
side surface of the glass, as well as into the hydraulic
action of the washer system to apply washer fluid
stored in an on-board reservoir to the area of the
glass to be wiped. When combined, these components
provide the means to effectively maintain clear visi-
bility for the vehicle operator by removing excess
accumulations of rain, snow, bugs, mud, or other
minor debris from the outside liftgate glass surface
that might be encountered while driving the vehicle
under numerous types of inclement operating condi-
tions. The vehicle operator initiates all rear wiper
and washer system functions with the right multi-
function switch located on the right side of the steer-
ing column, just below the steering wheel. Moving
the switch control sleeve to a detent position selects
the rear wiper system operating mode. Moving the
switch control stalk forward to a momentary position
activates the rear washer pump/motor, which dis-
penses washer fluid onto the liftgate glass through
the rear washer nozzle and operates the rear wiper
system in the fixed cycle mode for as long as the
washer switch is closed plus about three wiper
sweeps.
When the ignition switch is in the Accessory or On
positions, battery current from a fuse in the Junction
Block (JB) is provided to the right multi-function
switch through a fused ignition switch output (run-
acc) circuit. A separate fuse in the JB provides bat-
tery current to the electronic control circuitry of the
rear wiper module through a fused B(+) circuit.
When the right multi-function switch control sleeve
On position is selected, the On position circuitry
within the switch directs a battery current rear
wiper motor control signal input to the rear wiper
module electronic circuitry, which causes the rear
wiper motor to run at a fixed continuous wipe cycle.
When the right multi-function switch control sleeve
Delay position is selected, the Delay position cir-
cuitry within the switch directs a battery current
rear washer switch output signal input to the rear
wiper module electronic circuitry, which causes the
rear wiper motor to run at a fixed intermittent wipe
cycle. When the right multi-function switch control
8R - 34 REAR WIPERS/WASHERSWJ
REAR WIPERS/WASHERS (Continued)

TERMINOLOGY
This is a list of terms and definitions used in the
wiring diagrams.
LHD .................Left Hand Drive Vehicles
RHD................Right Hand Drive Vehicles
ATX . . Automatic Transmissions-Front Wheel Drive
MTX....Manual Transmissions-Front Wheel Drive
AT ....Automatic Transmissions-Rear Wheel Drive
MT .....Manual Transmissions-Rear Wheel Drive
SOHC...........Single Over Head Cam Engine
DOHC..........Double Over Head Cam Engine
Built-Up-Export........ Vehicles Built For Sale In
Markets Other Than North America
Except Built-Up-Export . . Vehicles Built For Sale In
North America
DESCRIPTION - CIRCUIT INFORMATION
Each wire shown in the diagrams contains a code
which identifies the main circuit, part of the main
circuit, gage of wire, and color (Fig. 4).
WIRE COLOR CODE CHART
COLOR CODE COLOR
BL BLUE
BK BLACK
BR BROWN
DB DARK BLUE
DG DARK GREEN
GY GRAY
LB LIGHT BLUE
LG LIGHT GREEN
OR ORANGE
PK PINK
RD RED
TN TAN
VT VIOLET
WT WHITE
YL YELLOW
* WITH TRACER
Fig. 4 WIRE CODE IDENTIFICATION
1 - COLOR OF WIRE (LIGHT BLUE WITH YELLOW TRACER
2 - GAGE OF WIRE (18 GAGE)
3 - PART OF MAIN CIRCUIT (VARIES DEPENDING ON
EQUIPMENT)
4 - MAIN CIRCUIT IDENTIFICATION
WJ8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 5
WIRING DIAGRAM INFORMATION (Continued)

DESCRIPTION - CONNECTOR, GROUND AND
SPLICE INFORMATION
CAUTION: Not all connectors are serviced. Some
connectors are serviced only with a harness. A typ-
ical example might be the Supplemental Restraint
System connectors. Always check parts availability
before attempting a repair.
IDENTIFICATION
In-line connectors are identified by a number, as
follows:
²In-line connectors located in the engine compart-
ment are C100 series numbers
²In-line connectors located in the Instrument
Panel area are C200 series numbers.
²In-line connectors located in the body are C300
series numbers.
²Jumper harness connectors are C400 series
numbers.
²Grounds and ground connectors are identified
with a ªGº and follow the same series numbering as
the in-line connectors.
²Splices are identified with an ªSº and follow the
same series numbering as the in-line connectors.
²Component connectors are identified by the com-
ponent name instead of a number. Multiple connec-
tors on a component use a C1, C2, etc. identifier.
LOCATIONS
Section 8W-91 contains connector/ground/splice
location illustrations. The illustrations contain the
connector name (or number)/ground number/splice
number and component identification. Connector/
ground/splice location charts in section 8W-91 refer-
ence the figure numbers of the illustrations.
The abbreviation T/O is used in the component
location section to indicate a point in which the wir-
ing harness branches out to a component. The abbre-
viation N/S means Not Shown in the illustrations
WARNING
WARNINGS - GENERAL
WARNINGSprovide information to prevent per-
sonal injury and vehicle damage. Below is a list of
general warnings that should be followed any time a
vehicle is being serviced.
WARNING: ALWAYS WEAR SAFETY GLASSES FOR
EYE PROTECTION.
WARNING: USE SAFETY STANDS ANYTIME A PRO-
CEDURE REQUIRES BEING UNDER A VEHICLE.WARNING: BE SURE THAT THE IGNITION SWITCH
ALWAYS IS IN THE OFF POSITION, UNLESS THE
PROCEDURE REQUIRES IT TO BE ON.
WARNING: SET THE PARKING BRAKE WHEN
WORKING ON ANY VEHICLE. AN AUTOMATIC
TRANSMISSION SHOULD BE IN PARK. A MANUAL
TRANSMISSION SHOULD BE IN NEUTRAL.
WARNING: OPERATE THE ENGINE ONLY IN A
WELL-VENTILATED AREA.
WARNING: KEEP AWAY FROM MOVING PARTS
WHEN THE ENGINE IS RUNNING, ESPECIALLY THE
FAN AND BELTS.
WARNING: TO PREVENT SERIOUS BURNS, AVOID
CONTACT WITH HOT PARTS SUCH AS THE RADIA-
TOR, EXHAUST MANIFOLD(S), TAIL PIPE, CATA-
LYTIC CONVERTER AND MUFFLER.
WARNING: DO NOT ALLOW FLAME OR SPARKS
NEAR THE BATTERY. GASES ARE ALWAYS
PRESENT IN AND AROUND THE BATTERY.
WARNING: ALWAYS REMOVE RINGS, WATCHES,
LOOSE HANGING JEWELRY AND AVOID LOOSE
CLOTHING.
DIAGNOSIS AND TESTING - WIRING HARNESS
TROUBLESHOOTING TOOLS
When diagnosing a problem in an electrical circuit
there are several common tools necessary. These tools
are listed and explained below.
²Jumper Wire - This is a test wire used to con-
nect two points of a circuit. It can be used to bypass
an open in a circuit.
WARNING: NEVER USE A JUMPER WIRE ACROSS
A LOAD, SUCH AS A MOTOR, CONNECTED
BETWEEN A BATTERY FEED AND GROUND.
²Voltmeter - Used to check for voltage on a cir-
cuit. Always connect the black lead to a known good
ground and the red lead to the positive side of the
circuit.
CAUTION: Most of the electrical components used
in today's vehicles are Solid State. When checking
voltages in these circuits, use a meter with a 10 -
megohm or greater impedance rating.
WJ8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 7
WIRING DIAGRAM INFORMATION (Continued)

8W-91 CONNECTOR/GROUND/SPLICE LOCATION
TABLE OF CONTENTS
page
CONNECTOR/GROUND/SPLICE LOCATION
DESCRIPTION..........................1
CONNECTOR/GROUND/SPLICE
LOCATION
DESCRIPTION
This section provides illustrations identifying con-
nector, ground, and splice locations in the vehicle.Connector, ground, and splice indexes are provided.
Use the wiring diagrams in each section for connec-
tor, ground, and splice identification. Refer to the
appropriate index for the proper figure number. For
items that are not shown in this section N/S is placed
in the Fig. column.
CONNECTORS
CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
A/C Compressor Clutch BK At A/C Compressor 9, 13
A/C Pressure Transducer BK Right Front of Engine Compartment 3, 4, 5
Accelerator Pedal Position
Sensor (Diesel)BK Rear of Engine Compartment Near
Fuel/Water Seperator7
Adjustable Pedals Module
(Except Built-up Export)GN Above Drivers Control Pedals N/S
Adjustable Pedals Motor/
Sensor Assembly (Except
Built-up Export)Above Drivers Control Pedals N/S
Adjustable Pedals Switch WT Drivers Lower Kick Panel 21
Airbag Control Module (ORC)
C1YL Below Center Floor Console, Near
Park Brake19, 20, 21, 22
Airbag Control Module (ORC)
C2YL Below Center Floor Console, Near
Park Brake19, 20, 21, 22
Ambient Temperature Sensor BK On Radiator Center Support 5
Antenna Module (Built-up-
export)WT Above Right Quarter Window N/S
Ash Receiver Lamp BK Below Cigarette Lighter 19, 20
Automatic Day/Night Mirror BK In Front of Rear View Mirror N/S
Automatic Headlamp Light
Sensor/VTSS LEDBK Near Left Instrument Panel Speaker 19, 20
Automatic Zone Control
Module - C1 (AZC)WT Left Side of HVAC Housing N/S
Automatic Zone Control
Module - C2 (AZC)WT Left Side of HVAC Housing N/S
Battery Temperature Sensor BK Below Battery Tray 4, 5
Blower Motor BK Behind Right Hand Side of
Instrument PanelN/S
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 1

(9) Remove the PDC and the right headlamp and
dash wire harness from the engine compartment as a
unit.
DISASSEMBLY
POWER DISTRIBUTION CENTER DISASSEMBLY
PDC HOUSING LOWER COVER REMOVAL
The Power Distribution Center (PDC) cover, the
PDC housing lower cover, the PDC relay wedges, the
PDC relay cassettes and the PDC B(+) terminal stud
module are available for service replacement. The
PDC cover can be simply unlatched and removed
from the PDC housing without the PDC being
removed or disassembled. Service of the remaining
PDC components requires that the PDC be removed
from its mounting and disassembled. Refer toWiring
Repairin Wiring Diagrams for the location of the
wiring repair procedures.
(1) Remove the battery from the battery support.
Refer toBattery Systemfor the location of the bat-
tery removal procedures.
(2) Unlatch and remove the cover from the PDC.
(3) Remove the two nuts that secure the two-holed
eyelet of the battery wire harness PDC take out to
the B(+) terminal studs near the front of the PDC.
(4) Remove the battery wire harness PDC take out
eyelet from the two PDC B(+) terminal studs.
(5) Disengage the latches on the PDC housing
mounts from the tabs on the PDC mounting stan-
chions on the battery support, and pull the PDC
housing upward to disengage the mounts from the
stanchions.
(6) Where the right headlamp and dash wire har-
ness exits the PDC, remove the tape that secures the
wire harness to the trough formation on the PDC
housing lower cover.
(7) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the latches on each side
and the front of the PDC housing that secure the
housing lower cover to the PDC and remove the
housing lower cover (Fig. 10).
PDC B+ TERMINAL MODULE REMOVAL
The Power Distribution Center (PDC) cover, the
PDC housing lower cover, the PDC relay wedges, the
PDC relay cassettes and the PDC B(+) terminal stud
module are available for service replacement. The
PDC cover can be simply unlatched and removed
from the PDC housing without the PDC being
removed or disassembled. Service of the remaining
PDC components requires that the PDC be removed
from its mounting and disassembled. Refer toWiring
Repairin Wiring Diagrams for the location of the
wiring repair procedures.(1) Remove the PDC housing lower cover.
(2) From the top of the PDC housing, use a small
screwdriver or a terminal pick tool (Special Tool Kit
6680) to release the two latches that secure the B(+)
terminal module in the PDC.
(3) Gently and evenly press the two B(+) terminal
studs down through the bus bar in the PDC.
(4) From the bottom of the PDC housing, remove
the B(+) terminal module from the PDC.
PDC RELAY WEDGE REMOVAL
The Power Distribution Center (PDC) cover, the
PDC housing lower cover, the PDC relay wedges, the
PDC relay cassettes and the PDC B(+) terminal stud
module are available for service replacement. The
PDC cover can be simply unlatched and removed
from the PDC housing without the PDC being
removed or disassembled. Service of the remaining
PDC components requires that the PDC be removed
from its mounting and disassembled. Refer toWiring
Repairin Wiring Diagrams for the location of the
wiring repair procedures.
(1) Remove the PDC housing lower cover.
(2) Remove each of the relays from the PDC relay
wedge to be removed.
(3) From the bottom of the PDC housing, use a
small screwdriver or a terminal pick tool (Special
Fig. 10 PDC Housing Lower Cover Remove/Install -
Typical
1 - TROUGH FORMATION
2 - LATCHES (5)
3 - PDC HOUSING LOWER COVER
4 - WIRE HARNESS
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 9
POWER DISTRIBUTION CENTER (Continued)

PDC LOWER COVER INSTALLATION
(1) Align the PDC housing lower cover on the bot-
tom of the PDC.
(2) Evenly press the lower cover into place until
latches are fully engaged.
(3) Where the right headlamp and dash harness
enters the PDC, tape the harness securely to the
trough formation on the PDC lower cover.
(4) Install the PDC in its mounting location on the
battery support.
(5) Install the battery wire harness over the two
PDC B+ terminal studs. Torque the nuts to 11.3 N´m
(100 in. lbs.).
(6) Install the battery. Refer to Battery System for
the procedure.
(7) Install the PDC cover.
INSTALLATION
The Power Distribution Center (PDC) main hous-
ing unit, the PDC fuse wedges and the PDC bus bars
cannot be repaired and are only serviced as a unit
with the right headlamp and dash wire harness. If
the PDC main housing unit, the fuse wedges or the
bus bars are faulty or damaged, the entire PDC and
right headlamp and dash wire harness unit must be
replaced.
(1) Position the PDC and the right headlamp and
dash wire harness unit in the engine compartment.
(2) Engage the PDC housing mounts with the
stanchions of the battery support and push the unit
downward until the mount latches fully engage the
mounting tabs on the stanchions.
(3) Install the two-holed eyelet of the battery wire
harness PDC take outs onto the two PDC B(+) termi-
nal studs.
(4) Install and tighten the nuts that secure the
eyelet of the battery wire harness PDC take outs to
the B(+) terminal studs. Tighten the nuts to 11.3
N´m (100 in. lbs.).
(5) Engage each of the retainers that secure the
right headlamp and dash wire harness to the vehicle
body and chassis components. Refer toConnector
Locationsin Wiring Diagrams for the location of
more information on the right headlamp and dash
wire harness retainer locations.
(6) Install all of the fasteners that secure each of
the right headlamp and dash wire harness ground
eyelets to the vehicle body and chassis components.
Refer toConnector Locationsin Wiring Diagrams
for the location of more information on the ground
eyelet locations.
(7) Reconnect each of the right headlamp and dash
wire harness connectors. Refer toConnector Loca-
tionsin Wiring Diagrams for the location of more
information on the right headlamp and dash wire
harness connector locations. For connectors securedwith screws, tighten the screws to 4.3 N´m (38 in.
lbs.).
(8) Reconnect the battery negative cable.
POWER OUTLET
DESCRIPTION - FRONT POWER OUTLET
An accessory power outlet is standard equipment
on this model. The power outlet is installed in the
instrument panel center lower bezel, which is located
near the bottom of the instrument panel center stack
area, below the heater and air conditioner controls.
The power outlet base is secured by a snap fit within
the center lower bezel. A hinged door with an over-
center spring flips closed to conceal and protect the
power outlet base when the power outlet is not being
used, and flips open below the center lower bezel
while the power outlet is in use.
The power outlet receptacle unit and the power
outlet door are each available for service replace-
ment.
OPERATION - FRONT POWER OUTLET
The power outlet base or receptacle shell is con-
nected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The power outlet receives battery voltage from a fuse
in the junction block at all times.
While the power outlet is very similar to a cigar
lighter base unit, it does not include the two small
spring-clip retainers inside the bottom of the recepta-
cle shell that are used to secure the cigar lighter
heating element to the insulated contact.
DIAGNOSIS AND TESTING - POWER OUTLET
For complete circuit diagrams, refer toHorn/Ci-
gar Lighter/Power Outletin Wiring Diagrams.
WARNING: REFER TO RESTRAINTS BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the junction block. If OK, go to Step 3. If not OK,
repair the open fused B(+) circuit to the Power Dis-
tribution Center (PDC) fuse as required.
(3) Open the power outlet door. Check for continu-
ity between the inside circumference of the power
8W - 97 - 12 8W-97 POWER DISTRIBUTIONWJ
POWER DISTRIBUTION CENTER (Continued)

(10) Place a piece of wood (2 x 2) between the jack
stand and the engine vibration damper.
(11) Remove the engine mount through bolts.
(12) Using the jack stand, raise the engine until
adequate clearance is obtained to remove the oil pan.
(13) Remove transmission oil cooling lines (if
equipped) and oxygen sensor wiring supports that
are attached to the oil pan studs.
(14) Remove the oil pan bolts and studs. Carefully
slide the oil pan and gasket to the rear. If equipped
with an oil level sensor, take care not to damage the
sensor.
INSTALLATION
(1) Clean the block and pan gasket surfaces.
(2) Fabricate 4 alignment dowels from 1 1/2 x 1/4
inch bolts. Cut the head off the bolts and cut a slot
into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 78).
(3) Install two dowels in the timing case cover.
Install the other two dowels in the cylinder block
(Fig. 79).
(4) Apply MopartSilicone Rubber Adhesive Seal-
ant on cylinder block to rear main bearing cap cor-
ners and cylinder block to front cover joints (four
places) (Fig. 80).
(5) Slide the one-piece gasket over the dowels and
onto the block and timing case cover.
(6) Position the oil pan over the dowels and onto
the gasket. If equipped with an oil level sensor, take
care not to damage the sensor.
(7) Install the 1/4 inch oil pan bolts. Tighten these
bolts to 9.5 N´m (84 in. lbs.) torque. Install the 5/16
inch oil pan bolts (Fig. 81). Tighten these bolts to 15
N´m (132 in. lbs.) torque.
(8) Remove the dowels. Install the remaining 1/4
inch oil pan bolts. Tighten these bolts to 9.5 N´m (84
in. lbs.) torque.
Fig. 78 Fabrication of Alignment Dowels
1 - 1/488ý 1 1/288BOLT
2 - DOWEL
3 - SLOT
Fig. 79 Position of Dowels in Cylinder Block
1 - DOWEL HOLES
2 - CYLINDER BLOCK
3 - 5/1688HOLES
4 - 5/1688HOLES
Fig. 80 Oil Pan Sealer Location
1 - SEALER LOCATIONS
Fig. 81 Position of 5/16 inch Oil Pan Bolts
1 - OIL PAN
2 - OIL PAN DRAIN PLUG
WJENGINE - 4.0L 9 - 55
OIL PAN (Continued)

(9) Lower the engine until it is properly located on
the engine mounts.
(10) Install the through bolts and tighten the nuts.
(11) Lower the jack stand and remove the piece of
wood.
(12) Install the engine flywheel and transmission
torque converter housing access cover.
(13) Install the engine starter motor. (Refer to 8 -
ELECTRICAL/STARTING/STARTER MOTOR -
INSTALLATION).
(14) Connect the exhaust pipe to the hanger and to
the engine exhaust manifold.
(15) Install transmission oil cooling lines (if
equipped) and oxygen sensor wiring supports that
attach to the oil pan studs.
(16) Install the oil pan drain plug (Fig. 81).
Tighten the plug to 34 N´m (25 ft. lbs.) torque.
(17) Lower the vehicle.
(18) Connect negative cable to battery.
(19) Fill the oil pan with engine oil to the specified
level.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR FAN. DO
NOT WEAR LOOSE CLOTHING.
(20) Start the engine and inspect for leaks.
ENGINE OIL PRESSURE
SENSOR
DESCRIPTION
The 3±wire, solid-state engine oil pressure sensor
(sending unit) is located in an engine oil pressure
gallery.
OPERATION
The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to theinstrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.
OIL PUMP
REMOVAL
A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
(1) Drain the engine oil.
(2) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(3) Remove the pump-to-cylinder block attaching
bolts. Remove the pump assembly with gasket (Fig.
82).
CAUTION: If the oil pump is not to be serviced, DO
NOT disturb position of oil inlet tube and strainer
assembly in pump body. If the tube is moved within
the pump body, a replacement tube and strainer
assembly must be installed to assure an airtight
seal.
Fig. 82 Oil Pump Assembly
1 - OIL FILTER ADAPTOR
2 - BLOCK
3 - GASKET
4 - OIL INLET TUBE
5 - OIL PUMP
6 - STRAINER ASSEMBLY
7 - ATTACHING BOLTS
9 - 56 ENGINE - 4.0LWJ
OIL PAN (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL -
REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
6. Dirt or water in fuel system. 6. Clean system and replace fuel filter.
7. Faulty fuel pump, relay or wiring. 7. Repair or replace as necessary.
ENGINE STALLS OR ROUGH
IDLE1. Idle speed set to low. 1. (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/IDLE AIR CONTROL
MOTOR - REMOVAL).
2. Idle mixture to lean or to rich. 2. Refer to Powertrain Diagnosis
Information.
3. Vacuum leak. 3. Inspect intake manifold and vacuum
hoses, repair or replace as necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL -
REMOVAL).
5. Incorrect engine timing. 5. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD PROCEDURE).
1. ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped spark
plugs.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
2. Dirt or water in fuel system. 2. Clean system and replace fuel filter.
3. Faulty fuel pump. 3. (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/FUEL PUMP - DIAGNOSIS
AND TESTING).
4. Blown cylinder head gasket. 4. Replace cylinder head gasket.
5. Low compression. 5. (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING), repair as necessary.
6. Burned, warped or pitted valves. 6. Replace as necessary.
7. Plugged or restricted exhaust
system.7. Inspect and replace as necessary.
8. Faulty coil. 8. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL -
REMOVAL).
WJENGINE - 4.7L 9 - 65
ENGINE - 4.7L (Continued)