2001 DODGE TOWN AND COUNTRY check engine light

²Engine running at 420 to 480 rpm for 10 sec-
onds
²Oil pressure switch closed to ground for (1 sec-
ond minimum, 2 seconds maximum)
Chime rate: 168 to 192 chimes per minute.
DIAGNOSIS AND TESTING - SEAT BELT CHIME
The seat belt chime will sound for 4 to 8 seconds,
when the ignition is turned on and the driver's seat
belt is not buckled (seat belt switch is closed to
ground). This is a reminder to the driver to buckle
the seat belt. The seat belt lamp is controlled by the
ORC. The cluster will also bulb check the seat belt
warning lamp for 6 seconds. Buckling the driver's
seat belt before the time out has expired will cause
the chime to stop immediately. Chime rate: 38 to 62
chimes per minute but the lamp will remain on until
6 seconds have expired.
To test the seat belt warning system, the ignition
switch must be in the OFF position for 1 minute
before starting the test. Turn the ignition switch to
the on position with the driver's seat belt not buck-
led. The seat belt warning lamp should light and the
chime should sound 4 to 8 seconds.
DIAGNOSIS AND TESTING - SEAT BELT LAMP
The seat belt lamp in the instrument cluster sig-
nals the vehicle passengers to fasten their seat belts.
The seat belt lamp is illuminated directly by the
instrument cluster for 6 seconds after the instrument
cluster receives the message from the ORC. The seat
belt lamp is therefore illuminated for 6 seconds
whenever the ignition switch is moved to run/start
position.
(1) While ignition is off, the seat belt lamp will not
be illuminated.
(2) The ignition power feed status will be updated
every 250 milliseconds or on change.
(3) This lamp will be checked by the instrument
cluster for 6 seconds with every run/start cycle of the
ignition switch.
DIAGNOSIS AND TESTING - TURN SIGNAL ON
CHIME
The turn signal on chime will warn the driver that
the turn signals have been left on. When the body
control module receives a turn signal input for 1/4.0
mile, vehicle speed is greater than 24 km/h (15 mph),
the chime will sound continuously until the turn sig-nal is turned OFF. If vehicle speed drops below 24
km/h (15 mph) prior to the warning being activated,
the accumulated distance traveled will be reset. The
turn signal chime is not activated when the emer-
gency flashers are turned on. Chime rate: 50612
chimes per minute.
For the turn signal warning system to operate:
²Must have input from either the right or left
turn signal lamps. Creates a voltage change between
0 and battery voltage.
²The vehicle speed sensor sends a message to the
Powertrain Control Module that vehicle has exceeded
24 km/h (15 mph) for 1/4.0 mile).
²When the above two conditions are met, the
chime will sound. The chime will stop when no fur-
ther voltage change is detected.
²If hazard warning signals are pulsing, no chime
will sound.
²If speed drops below 24 km/h (15 mph) before
the warning is issued, the warning will not be issued
and the distance counter will be reset.
²If turn signal lamps are not working properly,
the chime will not sound.
²When using the scan tool, refer to the proper
Body Diagnostic Manual for the procedure.
DIAGNOSIS AND TESTING - WARNING LAMP
ANNOUNCEMENT CHIME
The warning lamp announcement chime will warn
the driver to scan the instrument cluster to observe
which warning lamp is illuminated. Whenever the
volts, low fuel, airbag, door ajar or gate ajar lamps
are first illuminated, the chime will sound one tone.
The door/liftgate ajar warning lamp announcement
chime sounds only if the vehicle speed is above 4
m.p.h.
Two seconds after ignition switch is turned ON or
until the seat belt warning chime ends, all warning
announcement chimes will be consolidated into one
warning announcement. This will occur 2 seconds
after the seat belt warning chime ends. If a warning
announcement should occur while another warning
chime in progress (turn signal, low oil pressure or
high speed warnings), no additional chimes will
sound after the chime in progress ends. All associ-
ated lamps will be illuminated, and the active chime
will be the warning announcement.
RSCHIME/BUZZER8B-3
CHIME/BUZZER (Continued)
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²Front Fog Lamp Relay Actuation
²Front and Rear Blower Motor Relay Actuation
²Accessory Relay Actuation
²Electronic Back Light (EBL) Rear Defogger
²Horn Relay Actuation
²Park Lamp Relay Actuation
²Name Brand Speaker (NBS) Relay Actuation
²Headlamp Washer Relay Actuation
²Diesel Cabin Heater (Diesel Engine Vehicles)
The following inputs areReceived/Monitoredby
the Front Control Module:
²B+ Connection Detection
²Ambient Temperature Sensing
²Right/Left Park Lamp Outage
²Ignition Switch Start Only
²Ignition Switch Run and Start Only
²Washer Fluid Level
²Windshield Wiper Park
²Brake Fluid Level
²Back-Up switch
²Stop Lamp Sense
²Engine Crank Signal (Diesel Engine Vehicles)
²Horn Input
DIAGNOSIS AND TESTING - FRONT CONTROL
MODULE
The front control module is a printed circuit board
based module with a on-board micro-processor. The
front control module interfaces with other electronic
modules in the vehicle via the Programmable Com-
munications Interface (PCI) data bus (J1850). In
order to obtain conclusive testing the Programmable
Communications Interface (PCI) data bus network
and all of the electronic modules that provide inputs
to, or receive outputs from the front control module
must be checked. All PCI (J1850) communication
faults must be resolved prior to further diagnosing
any front control module related issues.
The front control module was designed to be diag-
nosed with an appropriate diagnostic scan tool, such
as the DRB IIIt. The most reliable, efficient, and
accurate means to diagnose the front control module
requires the use of a DRB IIItscan tool and the
proper Body Diagnostic Procedures manual.
Before any testing of the front control module is
attempted, the battery should be fully charged and
all wire harness and ground connections inspected
around the affected areas on the vehicle.
REMOVAL
(1) Disconnect the positive and negative battery
cables from the battery.
(2) Remove the battery from the vehicle. Refer to
the procedure in Battery Systems.(3) Using a long flat-pladed screwdriver, gently
twist the Intelligent Power Module (IPM) retaining
clip outboard to free the intelligent power module
from its mounting bracket (Fig. 6). Rotate intelligent
power module upward to access the Front Control
Module (FCM) retaining screws.
(4) Remove the front control module retaining
screws.
(5) Using both hands, pull the front control module
straight from the intelligent power module assembly
to disconnect the 49-way electrical connector (Fig. 7)
and remove the front control module from the vehi-
cle.
INSTALLATION
(1) Install the front control module in the intelli-
gent power module assembly by pushing the 49-way
electrical connector straight in (Fig. 7).
(2) Install the front control module retaining
screws. Torque the screws to 7 in. lbs.
(3) Rotate the intelligent power module assembly
downward to secure in mounting bracket.
(4) Install the battery in the vehicle. Refer to the
procedure in Battery Systems.
(5) Connect the positive and negative battery
cables.
NOTE: If the vehicle is not equipped with Name
Brand Speakers (NBS, Infinity) or Headlamp Wash-
ers the DRB IIITmust be used to Disable the appro-
priate relays in the Intelligent Power Module
Assembly.
Fig. 6 REMOVING INTELLIGENT POWER MODULE
8E - 6 ELECTRONIC CONTROL MODULESRS
FRONT CONTROL MODULE (Continued)
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PCM determines basic fuel injector pulse width from
this input.
²The PCM determines atmospheric air pressure
from the MAP sensor input to modify injector pulse
width.
When the key is in the ON position and the engine
is not running (zero rpm), the Auto Shutdown (ASD)
and fuel pump relays de-energize after approximately
1 second. Therefore, battery voltage is not supplied to
the fuel pump, ignition coil, fuel injectors and heated
oxygen sensors.
ENGINE START-UP MODE
This is an OPEN LOOP mode. If the vehicle is in
park or neutral (automatic transaxles) or the clutch
pedal is depressed (manual transaxles) the ignition
switch energizes the starter relay. The following
actions occur when the starter motor is engaged.
²If the PCM receives the camshaft position sensor
and crankshaft position sensor signals, it energizes
the Auto Shutdown (ASD) relay and fuel pump relay.
If the PCM does not receive both signals within
approximately one second, it will not energize the
ASD relay and fuel pump relay. The ASD and fuel
pump relays supply battery voltage to the fuel pump,
fuel injectors, ignition coil and heated oxygen sen-
sors.
²The PCM energizes the injectors (on the 69É
degree falling edge) for a calculated pulse width until
it determines crankshaft position from the camshaft
position sensor and crankshaft position sensor sig-
nals. The PCM determines crankshaft position within
1 engine revolution.
²After determining crankshaft position, the PCM
begins energizing the injectors in sequence. It adjusts
injector pulse width and controls injector synchroni-
zation by turning the individual ground paths to the
injectors On and Off.
²When the engine idles within664 RPM of its
target RPM, the PCM compares current MAP sensor
value with the atmospheric pressure value received
during the Ignition Switch On (zero RPM) mode.
Once the ASD and fuel pump relays have been
energized, the PCM determines injector pulse width
based on the following:
²Battery voltage
²Engine coolant temperature
²Engine RPM
²Inlet/Intake air temperature (IAT)
²MAP
²Throttle position
²The number of engine revolutions since cranking
was initiated
During Start-up the PCM maintains ignition tim-
ing at 9É BTDC.
ENGINE WARM-UP MODE
This is an OPEN LOOP mode. The following inputs
are received by the PCM:
²Engine coolant temperature
²Manifold Absolute Pressure (MAP)
²Inlet/Intake air temperature (IAT)
²Crankshaft position (engine speed)
²Camshaft position
²Knock sensor
²Throttle position
²A/C switch
²Battery voltage
²Vehicle speed
²Speed control
²O2 sensors
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts ignition timing and engine idle
speed. Engine idle speed is adjusted through the idle
air control motor.
CRUISE OR IDLE MODE
When the engine is at operating temperature this
is a CLOSED LOOP mode. During cruising or idle
the following inputs are received by the PCM:
²Inlet/Intake air temperature
²Engine coolant temperature
²Manifold absolute pressure
²Crankshaft position (engine speed)
²Camshaft position
²Knock sensor
²Throttle position
²Exhaust gas oxygen content
²A/C control positions
²Battery voltage
²Vehicle speed
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts engine idle speed and ignition
timing. The PCM adjusts the air/fuel ratio according
to the oxygen content in the exhaust gas (measured
by the upstream and downstream heated oxygen sen-
sor).
The PCM monitors for engine misfire. During
active misfire and depending on the severity, the
PCM either continuously illuminates or flashes the
malfunction indicator lamp (Check Engine light on
instrument panel). Also, the PCM stores an engine
misfire DTC in memory.
The PCM performs several diagnostic routines.
They include:
²Oxygen sensor monitor
²Downstream heated oxygen sensor diagnostics
during open loop operation (except for shorted)
8E - 20 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)
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(1) Check battery before performing this test. Bat-
tery must be fully charged.
(2) Connect a volt-ampere tester to the battery ter-
minals. Refer to the operating instructions provided
with the tester being used.
(3) To disable the ignition and fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location.
(4) Verify that all lights and accessories are OFF,
and the transmission shift selector is in the PARK
and SET parking brake.
CAUTION: Do not overheat the starter motor or
draw the battery voltage below 9.6 volts during
cranking operations.
(5) Rotate and hold the ignition switch in the
START position. Observe the volt-ampere tester (Fig.
2).
²If voltage reads above 9.6 volts, and amperage
draw reads above 280 amps, check for engine seizing
or faulty starter.
²If voltage reads 12.4 volts or greater and amper-
age reads 0 to 10 amps, check for corroded cables
and/or bad connections.
²Voltage below 9.6 volts and amperage draw
above 300 amps, the problem is the starter. Replace
the starter refer to starter removal.
(6) After the starting system problems have been
corrected, verify the battery state-of-charge and
charge battery if necessary. Disconnect all testingequipment and connect ASD relay. Start the vehicle
several times to assure the problem has been cor-
rected.
SPECIFICATIONS
STARTER
MANUFACTURER NIPPONDENSO
Engine Application 2.4L /3.3/3.8L
Power rating 1.2 Kw
Voltage 12 VOLTS
No. of Fields 4
No. of Poles 4
Brushes 4
Drive Conventional Gear Train
Free running Test
Voltage 11
Amperage Draw 73 Amp
Minimum Speed 3401 RPM
SolenoidClosing Voltage 7.5 Volts
Cranking Amperage Draw
test150 - 200 Amps.
Engine should be up to operating temperature.
Extremely heavy oil or tight engine will increase
starter amperage draw.
Torques
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Starter Mounting Bolts 47.4 35
Starter Solenoid Battery
Nut11.3 8.3 100
8F - 32 STARTINGRS
STARTING (Continued)
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DAYTIME RUNNING LAMPS
Power is reduced using pulse-width modulation to
the high beams, where by the power is switched on
and off rapidly instead of remaining on continuously.
The duration and interval of the power pulses is pro-
grammed into the Front Control Module (FCM).
HEADLAMP SYSTEM
The headlamp system will default to headlamps
ON position when ignition switch is ON and when an
open or short circuit failure occurs on the headlamp
switch input. The system will return to normal oper-
ation when the open or short is repaired. A fault will
be reported by the BCM when a failure occurs on the
dimmer or headlamp switch input.
If the exterior lamps are ON and the headlamp
switch is in any position other than OFF or AUTO
and with the ignition switch OFF (LOCK) after 3
minutes the BCM sends a message via J1850 to the
FCM informing the FCM to turn off the headlamps,
park lamps and fog lamps. This feature prevents the
vehicle battery from being discharged when the vehi-
cle lights have been left ON.
HEADLAMP TIME DELAY SYSTEM
The headlamp time delay system is activated by
turning the headlamps ON (high or low beam) while
the engine is running, turning the ignition switch
OFF, and then turning the headlamp switch OFF
within 45 seconds. The system will not activate if
more than 45 seconds elapse between ignition switch
OFF and headlamp switch OFF. The BCM will allow
the headlamps to remain ON for 90 seconds (config-
urable) before they automatically turn off (If the key
is in the ignition during the headlamp time delay
mode, then both the headlamps and park lamps
(including panel dimming) will be ON). Refer to the
Owner's Manual for more information.
If the headlamp switch is in the Auto Headlamp
Position, the headlamps are ON due to the night sig-
nal from the CMTC and the ignition switch is in any
position other than run/start, the BCM shall enter a
90 second (configurable) Auto Headlamps time delay
mode. If the key is in the ignition during the head-
lamp time delay mode, then both the headlamps and
park lamps (including panel dimming) will be ON. If
the key is not in the ignition, then only the head-
lamps will be ON. The BCM will allow the head-
lamps to remain ON for 90 seconds before they
automatically turn OFF. Refer to the Owner's Man-
ual for more information.
LAMP OUTAGE
If one or more of the following lamps (Low and/or
High beams) are out, then a ªlamps outº indicator
located in the cluster will illuminate.
OPTICAL HORN/HIGH BEAMS
When the multifunction switch is pulled to the first
detent (optical horn) signal, the headlamps are ON,
key-in the ignition the BCM shall send a message via
J1850 to the FCM to turn on the headlamps drivers
to illuminate all four filaments (Low and High
beams). When the multifunction switch is pulled to
the second detent (high beam) signal and the head-
lamps are ON, the BCM shall send a message via
J1850 to the FCM to turn on the headlamps drivers.
The High Beams are illuminated and the Low Beams
and Fog Lamps (if ON) are extinguished. If the head-
lamps were in the high beam configuration when
power was removed from the headlamps, the head-
lamps will be configured as low beam the next time
they are activated.
DIAGNOSIS AND TESTING
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.
When a vehicle experiences problems with the
headlamp system, verify the condition of the battery
connections, fuses, charging system, headlamp bulbs,
wire connectors, relay, high beam switch, dimmer
switch, and headlamp switch. Refer to the appropri-
ate 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 connec-
tors, splices and grounds.
Each vehicle is equipped with various lamp assem-
blies. A good ground is necessary for proper 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.
When it is necessary to remove components to ser-
vice another, it should not be necessary to apply
excessive force or bend a component to remove it.
Before damaging a trim component, verify hidden
fasteners or captured edges are not holding the com-
ponent in place.
RSLAMPS/LIGHTING - EXTERIOR8L-3
LAMPS/LIGHTING - EXTERIOR (Continued)
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the OFF position. Replace the first valid Sentry Key
in the ignition lock cylinder with the second valid
Sentry Key and turn the ignition switch back to the
ON position. The second valid Sentry Key must be
inserted within 15 seconds of removing the first valid
Sentry key.
(4) About ten seconds after the completion of Step
3, the indicator light will start to flash and a single
audible chime tone will sound to indicate that the
system has entered the9Customer Learn9program-
ming mode.
(5) Within sixty seconds of entering the9Customer
Learn9programming mode, turn the ignition switch
to the OFF position, replace the valid Sentry Key
with a blank Sentry Key transponder, and turn the
ignition switch back to the ON position.
(6) About ten seconds after the completion of Step
5, a single audible chime tone will sound and the
indicator light will stop flashing and stay on solid for
three seconds and then turn off to indicate that the
blank Sentry Key has been successfully programmed.
The SKIS will immediately exit the9Customer
Learn9programming mode and the vehicle may be
started using the newly programmed Sentry Key.
These steps must be completed in their entirety for
each additional Sentry Key to be programmed. If any
of the above steps are not completed in the given
sequence, or within the allotted time, the SKIS will
exit the9Customer Learn9programming mode and
the programming will be unsuccessful. The SKIS will
also automatically exit the9Customer Learn9pro-
gramming mode if:
²It sees a non-blank Sentry Key when it should
see a blank.
²If it has already programmed eight (8) valid
Sentry Keys.
²If the ignition switch is turned to the OFF posi-
tion for more than about fifty (50) seconds.
NOTE: If you attempt to start the vehicle while in
ªCustomer Learnº mode (LED flashing), the vehicle
will behave as though an invalid key is being used
(i.e. the engine will stall after two (2) seconds of
running). No faults will be logged.
NOTE: Once a Sentry Key has been programmed to
a particular vehicle, it cannot be used on any other
vehicle.VTSS/SKIS INDICATOR LAMP
DESCRIPTION
The Sentry Key Immobilizer System (SKIS) uses
an indicator light to convey information on the status
of the system to the customer. This light is shared
with the Vehicle Theft Security System (VTSS). The
light is located in the Message Center. The indicator
light is controlled by the Body Control Module (BCM)
based upon messages it receives from the Sentry Key
Immobilizer Module (SKIM) on the PCI bus.
OPERATION
The BCM performs a four second bulb check,
regardless of SKIM messages. After the bulb check,
the lamp is controlled according to SKIM messages.
Then, the SKIM sends messages to the BCM to oper-
ate the light based upon the results of the SKIS self
tests. The light may be actuated in two possible
ways, flashing or on solid. If the light comes on and
stays on solid after a power-up test, this indicates
that the SKIM has detected a system malfunction. If
the SKIM detects an invalid key when the ignition
switch is moved to the ON position, it sends a mes-
sage on the PCI bus to the BCM, to flash the light.
The SKIM can also send a message to flash the light
and generate a single audible chime at the same
time. These two events occurring simultaneously
indicate that the SKIS has been placed into the9Cus-
tomer Learn9mode. Refer to Electrical, Vehicle Theft
Security, Transponder Key, Standard Procedure -
Transponder Programming for more information on
the9Customer Learn9mode. If the light comes on
and stays on after the power-up test, diagnosis of the
SKIS should be performed using a DRB IIItscan tool
and the appropriate Body Diagnostic Procedures
manual. The light is not a serviceable component.
RSVEHICLE THEFT SECURITY8Q-5
TRANSPONDER KEY (Continued)
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The windshield wiper motor and linkage is located
in an integral wiper unit at the rear of the engine
compartment. The wiper unit must be removed to
gain access to the wiper motor.
REAR WIPER/WASHER SYSTEM
When continuous rear wiper operation is required,
the Body Control Module (BCM) will provide ignition
ON voltage to the rear wiper motor. When the wiper
switch is turned OFF, the BCM provides circuit
ground to operate the motor until the wipe cycle is
complete and the wiper arm returns to the base of
the rear window.
When intermittent rear wiper mode is selected, the
wiper motor will cycle every 7 seconds. The intermit-
tent delay time is also adjusted based upon vehicle
speed. With the vehicle traveling greater at 50 mph,
the cycle changes to every 5 seconds. DIAGNOSIS
AND TESTING
DIAGNOSIS AND TESTING - FRONT WIPER
SYSTEM
The windshield wiper system operates in several
modes:
²Low and high speed normal wipe
²Speed sensitive intermittent wipe
²Wipe after wash
²Pulse wipe
²Park (switch OFF)
The windshield wiper circuits are continuously
monitored and controlled by the Body Control Mod-
ule (BCM). If a problem occurs in the electronic com-
ponents, wiring, switch (except integral motor park
switch) and wiper motor a Diagnostic Trouble Code
(DTC) will be stored in the BCM memory. DTC's can
be retrieved using a DRB IIItscan tool. Refer to the
proper Body Diagnostic Procedures manual for DTC
descriptions and retrieval information.
The windshield wiper park switch and circuit is
monitored by the BCM. The park switch and circuit
can be tested using the Wiper System Diagnosis
table.
DIAGNOSIS AND TESTING - REAR WIPER
SYSTEM
The rear window wiper system operates in several
modes:
²Continuous wipe
²Intermittent wipe
²Wash
²Wipe after wash
The windshield wiper circuits are continuously
monitored and controlled by the Body Control Mod-
ule (BCM). If a problem occurs in the electronic com-
ponents, wiring, switch (except integral motor parkswitch) and wiper motor a Diagnostic Trouble Code
(DTC) will be stored in the BCM memory. The
DTC(s) can be retrieved using a DRB IIItscan tool.
DIAGNOSIS AND TESTING - FRONT
WIPER/WASHER SWITCH
To test the front wiper/washer portion of the multi-
function switch:
(1) Remove the multi-function switch (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
MULTI-FUNCTION SWITCH - REMOVAL).
(2) Using an ohmmeter check continuity reading
between switch pins. See (Fig. 1) and the table.
WIPER/WASHER SWITCH CONTINUITY
SWITCH POSITION RESISTANCE VALUE
BETWEEN
OFF 6 AND 7 = OPEN CIRCUIT
DELAY POSITION
1ST 6AND7=8KV680V
2ND 6AND7=6KV660V
3RD 6 AND 7 = 4.5 KV645V
4TH 6 AND 7 = 3.5 KV635V
5TH 6 AND 7 = 2.5 KV625V
6TH 6 AND 7 = 1.5 KV615V
LOW 6AND7=1KV610V
HIGH 6 AND7=1KV610V
WASH 6 AND 11 = CONTINUITY
DIAGNOSIS AND TESTING - FAILED PARK
SWITCH
If the wiper park switch has failed the windshield
wipers will operate as follows:
²SWITCH OFF- Wipers stop in current location
regardless of the park signal.
²INTERMITTENT MODE- Wipers operate at
low speed for one or more extra wipes or continu-
ously.
Fig. 1 WIPER/WASHER SWITCH PIN CALL OUT
8R - 2 WIPERS/WASHERSRS
WIPERS/WASHERS (Continued)
ProCarManuals.com

the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
should not be disassembled to determine the
cause of low compression unless some malfunc-
tion is present.
DIAGNOSIS AND TESTING - ENGINE 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 as necessary.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
²Gradually 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 provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft 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.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.(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.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
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. If a leak is
present in this area, remove transmission for further
inspection.
(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, oil gallery cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurize the crank-
case as previously described.
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.
9 - 4 ENGINE 2.4LRS
ENGINE 2.4L (Continued)
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