
OPERATION
OPERATION
When in theCustomer Usagemode of operation,
the system is armed when the vehicle is locked using
the:
²Power Door Lock Switches
²Remote Keyless Entry (RKE) Transmitter
²Key Cylinder Switches
After the vehicle is locked and the last door is
closed, the VTSS indicator in the instrument cluster
will flash quickly for 16 seconds, indicating that the
arming is in process. After 16 seconds, the LED will
continue to flash at a slower rate indicating that the
system is armed.
VTSS disarming occurs upon normal vehicle entry
by unlocking either door via the key cylinder or RKE
transmitter, or by starting the vehicle with a valid
Sentry Key. This disarming will also halt the alarm
once it has been activated.
A tamper alert exists to notify the driver that the
system has been activated. This alert consists of 3
horn pulses and the security telltail flashing for 30
seconds when the vehicle is disarmed. The tamper
alert will not occur if disarmed while alarming.
The VTSS will not arm by mechanically locking the
vehicle doors. This will manually override the sys-
tem.
OPERATION
The SKIS includes two valid Sentry Key transpon-
ders from the factory. These two Sentry Keys can be
used to program additional non-coded blank Sentry
Keys. These blank keys can be cut to match a valid
ignition key, but the engine will not start unless the
key transponder is also programmed to the vehicle.
The SKIS will recognize no more than eight valid
Sentry Key transponders at any one time.
The SKIS performs a self-test each time the igni-
tion switch is turned to the ON position, and will
store Diagnostic Trouble Codes (DTC's) if a system
malfunction is detected. The SKIS can be diagnosed,
and any stored DTC can be retrieved using a
DRBIIItscan tool as described in the proper Power-
train Diagnostic Procedures manual.
OPERATION
The SKIM transmits and receives RF signals
through a tuned antenna enclosed within a molded
plastic ring formation that is integral to the SKIM
housing. When the SKIM is properly installed on the
steering column, the antenna ring is oriented around
the circumference of the ignition lock cylinder hous-
ing. This antenna ring must be located within eight
millimeters (0.31 inches) of the Sentry Key in orderto ensure proper RF communication between the
SKIM and the Sentry Key transponder.
For added system security, each SKIM is pro-
grammed with a unique ªSecret Keyº code and a
security code. The SKIM keeps the ªSecret Keyº code
in memory. The SKIM also sends the ªSecret Keyº
code to each of the programmed Sentry Key tran-
sponders. The security code is used by the assembly
plant to access the SKIS for initialization, or by the
dealer technician to access the system for service.
The SKIM also stores in its memory the Vehicle
Identification Number (VIN), which it learns through
a PCI bus message from the PCM during initializa-
tion.
The SKIM and the PCM both use software that
includes a rolling code algorithm strategy, which
helps to reduce the possibility of unauthorized SKIS
disarming. The rolling code algorithm ensures secu-
rity by preventing an override of the SKIS through
the unauthorized substitution of the SKIM or the
PCM. However, the use of this strategy also means
that replacement of either the SKIM or the PCM
units will require a system initialization procedure to
restore system operation.
When the ignition switch is turned to the ON or
START positions, the SKIM transmits an RF signal
to excite the Sentry Key transponder. The SKIM then
listens for a return RF signal from the transponder
of the Sentry Key that is inserted in the ignition lock
cylinder. If the SKIM receives an RF signal with
valid ªSecret Keyº and transponder identification
codes, the SKIM sends a ªvalid keyº message to the
PCM over the PCI bus. If the SKIM receives an
invalid RF signal or no response, it sends ªinvalid
keyº messages to the PCM. The PCM will enable or
disable engine operation based upon the status of the
SKIM messages.
The SKIM also sends messages to the Instrument
Cluster which controls the VTSS indicator. The
SKIM sends messages to the Instrument Cluster to
turn the indicator on for about three seconds when
the ignition switch is turned to the ON position as a
ªbulbº test. After completion of the ªbulbº test, the
SKIM sends bus messages to keep the indicator off
for a duration of about one second. Then the SKIM
sends messages to turn the indicator on or off based
upon the results of the SKIS self-tests. If the VTSS
indicator comes on and stays on after the ªbulb testº,
it indicates that the SKIM has detected a system
malfunction and/or that the SKIS has become inoper-
ative.
If the SKIM detects an invalid key when the igni-
tion switch is turned to the ON position, it sends
messages to flash the VTSS indicator. The SKIM can
also send messages to flash the indicator to serve as
an indication to the customer that the SKIS has been
8Q - 2 VEHICLE THEFT SECURITYDR
VEHICLE THEFT SECURITY (Continued)

through the normally open contacts of the energized
wiper on/off relay and the normally open contacts of
the energized wiper high/low relay to the high speed
brush of the wiper motor, causing the wipers to cycle
at high speed.
When the Off position of the multi-function switch
control knob is selected, the instrument cluster sends
an electronic wiper switch off message to the FCM. If
the wiper motor was operating at high speed, the
FCM immediately de-energizes the wiper high/low
relay causing the wiper motor to return to low speed
operation. Then one of two events will occur. The
event that occurs depends upon the position of the
wiper blades on the windshield at the moment that
the control knob Off position is selected.
If the wiper blades are in the down position on the
windshield when the Off position is selected, the
park switch that is integral to the wiper motor is
closed to ground and provides a hard wired park
switch sense input to the FCM. The FCM then de-en-
ergizes the wiper on/off relay and the wiper motor
ceases to operate. If the wiper blades are not in the
down position on the windshield at the moment the
Off position is selected, the park switch is an open
circuit and the FCM keeps the wiper on/off relay
energized, which causes the wiper motor to continue
running at low speed until the wiper blades are in
the down position on the windshield and the park
switch input to the FCM is again closed to ground.
INTERMITTENT WIPE MODE
When the control knob on the control stalk of the
multi-function switch is moved to one of the Delay
interval positions the instrument cluster sends an
electronic wiper switch delay message to the FCM,
then the FCM electronic intermittent wipe logic cir-
cuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The FCM monitors the changing
state of the wiper motor park switch through a hard
wired park switch sense input. This input allows the
FCM to determine the proper intervals at which to
energize and de-energize the wiper on/off relay to
operate the wiper motor intermittently for one low
speed cycle at a time.
The FCM logic is also programmed to provide vehi-
cle speed sensitivity to the selected intermittent wipe
delay intervals. In order to provide this feature the
FCM monitors electronic vehicle speed messages
from the Powertrain Control Module (PCM) and dou-
bles the selected delay interval whenever the vehicle
speed is about sixteen kilometers-per-hour (ten miles-
per-hour) or less.PULSE WIPE MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for less than about one-half second,
the instrument cluster sends an electronic washer
switch message to the FCM, then the FCM the ener-
gizes the wiper on/off relay for one complete wipe
cycle. The FCM de-energizes the relay when the state
of the park switch sense changes to ground, parking
the wiper blades near the base of the windshield.
WASH MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for more than about one-half second,
the instrument cluster sends an electronic washer
switch message to the FCM, then the FCM directs
battery current to the washer pump/motor unit. This
will cause the washer pump/motor unit to be ener-
gized for as long as the Wash switch is held closed up
to about thirty seconds, and to de-energize when the
front Wash switch is released.
When the control knob is depressed to the momen-
tary Wash position while the wiper system is operat-
ing in one of the Delay interval positions, the washer
pump/motor operation is the same. However, the
FCM also energizes the wiper on/off relay to override
the selected delay interval and operate the wiper
motor in a continuous low speed mode for as long as
the control knob is held depressed, then de-energizes
the relay and reverts to the selected delay mode
interval several wipe cycles after the control knob is
released. If the control knob is held depressed for
more than about thirty seconds, the FCM will sus-
pend washer pump/motor operation until the knob is
released for about two seconds, then cycled back to
the Wash position.
WIPE-AFTER-WASH MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for more than about one-half second
while the wiper system is not operating, the instru-
ment cluster sends an electronic washer switch mes-
sage to the FCM, then the FCM the directs battery
current to the washer pump/motor unit and energizes
the wiper on/off relay. This will cause the washer
pump/motor unit to be energized and operate the
wiper motor in a continuous low speed mode for as
long as the Wash switch is held closed up to about
thirty seconds. When the control knob is released,
the FCM de-energizes the washer pump/motor unit,
but allows the wiper motor to operate for several
additional wipe cycles before it de-energizes the
wiper on/off relay and parks the wiper blades near
the base of the windshield.
DRWIPERS/WASHERS 8R - 5
WIPERS/WASHERS (Continued)

The washer fluid level switch is connected to the
vehicle electrical system through a dedicated take
out and connector of the right (except V-10 and diesel
engines) or left (V-10 and diesel engines only) head-
lamp and dash wire harness. The switch is connected
in series between a clean ground output of the Front
Control Module (FCM) on a sensor return circuit and
the washer fluid switch sense input to the FCM.
When the switch closes, the FMC senses the ground
on the washer fluid switch sense circuit. The FMC is
programmed to respond to this input by sending an
electronic washer fluid indicator lamp-on message to
the instrument cluster over the Programmable Com-
munications Interface (PCI) data bus. The instru-
ment cluster responds to this message by
illuminating the washer fluid indicator and by sound-
ing an audible chime tone warning.
The washer fluid level switch may be diagnosed
and tested using conventional diagnostic tools and
procedures. However, conventional diagnostic meth-
ods may not prove conclusive in the diagnosis of the
instrument cluster, the Front Control Module (FCM),
or the electronic message inputs to or outputs from
the instrument cluster and the FCM that control the
operation of the washer fluid visual and/or audible
indicators. The most reliable, efficient, and accurate
means to diagnose the washer fluid level indicator,
the instrument cluster, the FCM, or the electronic
message inputs and outputs related to the washer
fluid indicator requires the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
REMOVAL
The washer fluid level switch can be removed from
the washer reservoir without removing the reservoir
from the vehicle.
(1) Unlatch and open the hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Disconnect the washer hose from the barbed
outlet nipple of the washer pump/motor unit and
allow the washer fluid to drain into a clean container
for reuse.
(4) Disconnect the right (except V-10 and diesel
engine) or left (V-10 and diesel engine only) head-
lamp and dash wire harness connector for the washer
fluid level switch from the switch connector recepta-
cle (Fig. 7) or (Fig. 8).
NOTE: The pivoting float of the washer fluid level
switch must be in a horizontal position within the
reservoir in order to be removed. With the reservoir
empty and in an upright position, the pivoting float
will orient itself to the horizontal position when the
switch connector receptacle is pointed straight
upwards.(5) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the barbed nipple of the
washer fluid level switch out of the rubber grommet
seal on the reservoir sump. Care must be taken not
to damage the reservoir.
Fig. 7 Washer Fluid Level Switch Remove/Install -
Except V-10 & Diesel Engine
1 - WASHER HOSE
2 - WASHER RESERVOIR
3 - WASHER FLUID LEVEL SWITCH
4 - WIRE HARNESS
5 - WASHER PUMP/MOTOR
Fig. 8 Washer Fluid Level Switch Remove/Install -
V-10 & Diesel Engine
1 - WIRE HARNESS
2 - WASHER RESERVOIR
3 - WASHER PUMP/MOTOR
4 - WASHER HOSE
5 - WASHER FLUID LEVEL SWITCH
8R - 10 WIPERS/WASHERSDR
WASHER FLUID LEVEL SWITCH (Continued)

WIPER MODULE
DESCRIPTION
The wiper motor bracket is secured with two
screws below the wiper motor through two rubber
insulators to the bottom of the cowl plenum panel
beneath the cowl plenum cover/grille panel (Fig. 25).
Two screws secure the top of the wiper module
bracket to the cowl plenum panel through rubber
insulators located on the outboard end of each pivot
bracket. The ends of the wiper pivot shafts that pro-
trude through dedicated openings in the cowl plenum
cover/grille panel to drive the wiper arms and blades
are the only visible components of the wiper module.
The wiper module consists of the following major
components:
²Bracket- The wiper module bracket consists of
a long tubular steel main member that has a die castpivot bracket formation near each end where the two
wiper pivots are secured. A stamped steel clamp
secures the center of the tubular member to the die
cast bracket integral to the wiper motor with two
screws.
²Crank Arm- The wiper motor crank arm is a
stamped steel unit with a slotted hole on the driven
end that is secured to the wiper motor output shaft
with a nut, and has a ball stud secured to the drive
end.
²Linkage- Two stamped steel drive links con-
nect the wiper motor crank arm to the wiper pivot
lever arms. The left side drive link has a plastic sock-
et-type bushing on each end. The right side drive
link has a plastic socket-type bushing on one end,
and a plastic sleeve-type bushing on the other end.
The socket-type bushing on one end of each drive
link is snap-fit over the ball stud on the lever arm of
its respective pivot. The right side drive link sleeve-
type bushing end is then fit over the motor crank
arm ball stud, and the other socket-type bushing of
the left side drive link is snap-fit over the exposed
end of the wiper motor crank arm ball stud.
Fig. 24 Integrated Power Module
1 - 15 - CARTRIDGE FUSE
16 - 53 - BLADE FUSE
54 - HEATED MIRROR RELAY
55 - WIPER ON/OFF RELAY
56 - A/C CONDENSER FAN RELAY
57 - ENGINE CONTROL RELAY
58 - FUEL PUMP RELAY
59 - TRANSMISSION RELAY
60 - WIPER HIGH/LOW RELAY
61 - SPARE
62 - FOG LAMP RELAY
63 - ADJUSTABLE PEDAL RELAY
64 - A/C CLUTCH RELAY
65 - SPARE
66 - O2 RELAY
67 - SPARE
68 - SPARE
69 - SPARE
70 - SPARE
71 - SPARE
72 - STARTER RELAY
73 - PARK LAMP RELAY
Fig. 25 Wiper Module
1 - PIVOT BRACKET (2)
2 - TUBE
3 - CLAMP
4 - PIVOT SHAFT (2)
5 - INSULATOR (4)
6 - LINKAGE BUSHING (4)
7 - DRIVE LINK (2)
8 - PIVOT CRANK ARM (2)
9 - PIGTAIL WIRE CONNECTOR
10 - MOTOR CRANK ARM
11 - WIPER MOTOR
8R - 22 WIPERS/WASHERSDR
WIPER HIGH/LOW RELAY (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.
DR8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 7
WIRING DIAGRAM INFORMATION (Continued)

of oil and coolant. Can be used on threaded and
machined parts under all temperatures. This mate-
rial is used on engines with multi-layer steel (MLS)
cylinder head gaskets. This material also will pre-
vent corrosion. MopartGasket Sealant is available in
a 13 oz. aerosol can or 4oz./16 oz. can w/applicator.
FORM-IN-PLACE GASKET AND SEALER
APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier than using precut gas-
kets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 in.) diameter or less of sealant
to one gasket surface. Be certain the material sur-
rounds each mounting hole. Excess material can eas-
ily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing material off the location.
MopartEngine RTV GEN II or ATF RTV gasket
material should be applied in a continuous bead
approximately 3 mm (0.120 in.) in diameter. All
mounting holes must be circled. For corner sealing, a
3.17 or 6.35 mm (1/8 or 1/4 in.) drop is placed in the
center of the gasket contact area. Uncured sealant
may be removed with a shop towel. Components
should be torqued in place while the sealant is still
wet to the touch (within 10 minutes). The usage of a
locating dowel is recommended during assembly to
prevent smearing material off the location.
MopartGasket Sealant in an aerosol can should be
applied using a thin, even coat sprayed completely
over both surfaces to be joined, and both sides of a
gasket. Then proceed with assembly. Material in a
can w/applicator can be brushed on evenly over the
sealing surfaces. Material in an aerosol can should be
used on engines with multi-layer steel gaskets.
STANDARD PROCEDURE - ENGINE GASKET
SURFACE PREPARATION
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
Neveruse the following to clean gasket surfaces:
²Metal scraper
²Abrasive pad or paper to clean cylinder block
and head
²High speed power tool with an abrasive pad or a
wire brush (Fig. 2)
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
Only use the following for cleaning gasket surfaces:²Solvent or a commercially available gasket
remover
²Plastic or wood scraper (Fig. 2)
²Drill motor with 3M RolocŸ Bristle Disc (white
or yellow) (Fig. 2)
CAUTION: Excessive pressure or high RPM (beyond
the recommended speed), can damage the sealing
surfaces. The mild (white, 120 grit) bristle disc is
recommended. If necessary, the medium (yellow, 80
grit) bristle disc may be used on cast iron surfaces
with care.
REMOVAL
(1) Disconnect the battery negative cable.
(2) Remove hood. Mark hood hinge location for
reinstallation.
(3) Remove air cleaner assembly.
(4) Remove radiator core support bracket.
(5) Remove fan shroud with viscous fan assembly.
(6) Remove drive belt.
(7) Remove A/C compressor and secure away from
engine.
(8) Remove generator and secure away from
engine.
NOTE: Do NOT remove the phenolic pulley from the
P/S pump. It is not required for P/S pump removal.
(9) Remove power steering pump with lines
attached and secure away from engine.
(10) Drain cooling system.
(11) Disconnect the heater hoses from the engine.
Fig. 2 Proper Tool Usage For Surface Preparation
1 - ABRASIVE PAD
2 - 3M ROLOCŸ BRISTLE DISC
3 - PLASTIC/WOOD SCRAPER
9 - 10 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

CRANKSHAFT MAIN
BEARINGS
STANDARD PROCEDURE
MAIN BEARING FITTING
SELECT FIT IDENTIFICATION
The main bearings are ªselect fitº to achieve proper
oil clearances. For main bearing selection, the crank-
shaft position sensor target wheel has grade identifi-
cation marks stamped into it (Fig. 36). These marks
are read from left to right, corresponding with jour-
nal number 1, 2, 3, 4. The crankshaft position sensor
target wheel is mounted to the number 6 counter
weight on the crankshaft.
INSPECTION
Wipe the inserts clean and inspect for abnormal
wear patterns and for metal or other foreign material
imbedded in the lining. Normal main bearing insert
wear patterns are illustrated.
Inspect the back of the inserts for fractures, scrap-
ings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
MAIN BEARING JOURNAL DIAMETER
(CRANKSHAFT REMOVED)
Remove the crankshaft from the cylinder block(Re-
fer to 9 - ENGINE/ENGINE BLOCK/CRANKSHAFT
- REMOVAL).
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal
with a micrometer. Measure at two locations 90É
apart at each end of the journal.
The maximum allowable taper is 0.008mm (0.0004
inch.) and maximum out of round is 0.005mm (0.002
inch). Compare the measured diameter with the jour-
nal diameter specification (Main Bearing Fitting
Chart). Select inserts required to obtain the specified
bearing-to-journal clearance.
Install the crankshaft into the cylinder block(Refer
to 9 - ENGINE/ENGINE BLOCK/CRANKSHAFT -
INSPECTION).
Check crankshaft end play.
CRANKSHAFT MAIN BEARING SELECTION
(1) Service main bearings are available in four
grades. The chart below identifies the four service
grades available.
Crankshaft JOURNAL SIZE
SIZE mm (in.)
MARKING
9R9Size 63.488 - 63.496 mm
(2.4995 - 2.4998 in.)
9S9Size 63.496 - 63.500 mm (2.4998 - 2.4999
in.)
9T9Size 63.500 - 63.504 mm (2.4999 - 2.501
in.)
9U9Size 63.504 - 63.512 mm (2.5001 - 2.5004
in.)
Bearing size
Bearing
CodeSize Application
Upper Bearing
A.2.443 - 2.447
mmUse with crankshaft
size9R9
(.0961 - .0963
in.)
B2.439 - 2.443
mmUse with crankshaft
9S, T9
(0.960 -.o961
in.)
C2.435 - 2.439
mmUse with crankshaft
9U9
Fig. 36 MARKINGS ON TARGET WHEEL
1 - REARMOST CRANKSHAFT COUNTER WEIGHT
2 - TARGET WHEEL
3 - MAIN BEARING SELECT FIT MARKINGS
DRENGINE - 3.7L 9 - 43

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.If the oil leak source is not pos-
itively identified at this time, proceed with the air
leak detection test method.
Air Leak Detection Test Method
(1) Disconnect the breather cap to air cleaner hose
at the breather cap end. Cap or plug breather cap
nipple.
(2) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(3) Attach an air hose with pressure gauge and
regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kPa (3 PSI) of test pressure.
(4) Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provide the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
(5) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(6) If no leaks are detected, turn off the air supply
and remove the air hose and all plugs and caps.
Install the PCV valve and breather cap hose.(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, distributor seal,
camshaft bore cup plugs oil galley pipe plugs, oil
filter runoff, and main bearing cap to cylinder
block mating surfaces.
(4) If no leaks are detected, pressurize the crank-
case as outlined in the, Inspection (Engine oil Leaks
in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
DRENGINE - 3.7L 9 - 63
LUBRICATION (Continued)