2003 JEEP GRAND CHEROKEE Lock cylinder

OPERATION
Battery voltage is supplied to the 8 ignition coils
from the ASD relay. The Powertrain Control Module
(PCM) opens and closes each ignition coil ground cir-
cuit at a determined time for ignition coil operation.
Base ignition timing is not adjustable.By con-
trolling the coil ground circuit, the PCM is able to set
the base timing and adjust the ignition timing
advance. This is done to meet changing engine oper-
ating conditions.
The ignition coil is not oil filled. The windings are
embedded in an epoxy compound. This provides heat
and vibration resistance that allows the ignition coil
to be mounted on the engine.
Because of coil design, spark plug cables (second-
ary cables) are not used.
REMOVAL
An individual ignition coil is used for each spark
plug (Fig. 18). The coil fits into machined holes in the
cylinder head. A mounting stud/nut secures each coil
to the top of the intake manifold (Fig. 19). The bot-
tom of the coil is equipped with a rubber boot to seal
the spark plug to the coil. Inside each rubber boot is
a spring. The spring is used for a mechanical contact
between the coil and the top of the spark plug. These
rubber boots and springs are a permanent part of the
coil and are not serviced separately. An o-ring (Fig.
18) is used to seal the coil at the opening into the cyl-
inder head.
(1) Depending on which coil is being removed, the
throttle body air intake tube or intake box may need
to be removed to gain access to coil.
(2) Disconnect electrical connector (Fig. 19) from
coil by pushing downward on release lock on top of
connector and pull connector from coil.
(3) Clean area at base of coil with compressed air
before removal.
(4) Remove coil mounting nut from mounting stud
(Fig. 19).
(5) Carefully pull up coil from cylinder head open-
ing with a slight twisting action.
(6) Remove coil from vehicle.
INSTALLATION
(1) Using compressed air, blow out any dirt or con-
taminants from around top of spark plug.
(2) Check condition of coil o-ring and replace as
necessary. To aid in coil installation, apply silicone to
coil o-ring.
(3) Position ignition coil into cylinder head opening
and push onto spark plug. Do this while guiding coil
base over mounting stud.
(4) Install mounting stud nut and tighten to 8 N´m
(70 in. lbs.) torque.(5) Connect electrical connector to coil by snapping
into position.
(6) If necessary, install throttle body air tube or
box.
Fig. 18 Ignition CoilÐ4.7L V±8
1 - O-RING
2 - IGNITION COIL
3 - ELECTRICAL CONNECTOR
Fig. 19 Ignition Coil
1 - IGNITION COIL
2 - COIL ELECTRICAL CONNECTOR
3 - COIL MOUNTING STUD/NUT
8I - 12 IGNITION CONTROLWJ
IGNITION COIL (Continued)

IGNITION COIL CAPACITOR
DESCRIPTION
Two coil capacitors are used. One of them is
located near the center of, and on the left side of the
intake manifold (Fig. 20). The other capacitor is
located near the center of, and on the right side of
the intake manifold.
OPERATION
The 2 coil capacitors are used to prevent high-volt-
age spikes from interfering with the operation of cer-
tain powertrain sensors. They are also used to help
prevent radio interference.
REMOVAL
Two coil capacitors are used. One of them is
located near the center of, and on the left side of the
intake manifold (Fig. 21). The other capacitor is
located near the center of, and on the right side of
the intake manifold.
(1) Disconnect electrical connector at coil capacitor
(Fig. 21).
(2) Remove mounting nut.
(3) Remove capacitor from mounting stud.
INSTALLATION
(1) Position capacitor to manifold mounting stud.(2) Install nut and tighten to 8 N´m (70 in. lbs.)
torque.
(3) Connect electrical connector to capacitor (Fig.
21).
KNOCK SENSOR
DESCRIPTION
4.7L High-Output Engine
The 2 knock sensors are bolted into the cylinder
block under the intake manifold.
OPERATION
4.7L High-Output Engine
Two knock sensors are used on the 4.7L V-8 engine
if equipped with the high-output package; one for
each cylinder bank. When the knock sensor detects a
knock in one of the cylinders on the corresponding
bank, it sends an input signal to the Powertrain Con-
trol Module (PCM). In response, the PCM retards
ignition timing for all cylinders by a scheduled
amount.
Knock sensors contain a piezoelectric material
which constantly vibrates and sends an input voltage
(signal) to the PCM while the engine operates. As the
intensity of the crystal's vibration increases, the
knock sensor output voltage also increases.
Fig. 20 Coil Capacitor (Left Side Shown)
1 - ELECTRICAL CONNECTOR
2 - COIL CAPACITOR
3 - MOUNTING NUT
Fig. 21 Coil Capacitor (Left Side Shown)
1 - ELECTRICAL CONNECTOR
2 - COIL CAPACITOR
3 - MOUNTING NUT
WJIGNITION CONTROL 8I - 13

The voltage signal produced by the knock sensor
increases with the amplitude of vibration. The PCM
receives the knock sensor voltage signal as an input.
If the signal rises above a predetermined level, the
PCM will store that value in memory and retard
ignition timing to reduce engine knock. If the knock
sensor voltage exceeds a preset value, the PCM
retards ignition timing for all cylinders. It is not a
selective cylinder retard.
The PCM ignores knock sensor input during engine
idle conditions. Once the engine speed exceeds a
specified value, knock retard is allowed.
Knock retard uses its own short term and long
term memory program.
Long term memory stores previous detonation
information in its battery-backed RAM. The maxi-
mum authority that long term memory has over tim-
ing retard can be calibrated.
Short term memory is allowed to retard timing up
to a preset amount under all operating conditions (as
long as rpm is above the minimum rpm) except at
Wide Open Throttle (WOT). The PCM, using short
term memory, can respond quickly to retard timing
when engine knock is detected. Short term memory
is lost any time the ignition key is turned off.
NOTE: Over or under tightening the sensor mount-
ing bolts will affect knock sensor performance, pos-
sibly causing improper spark control. Always use
the specified torque when installing the knock sen-
sors.
REMOVAL
4.7L High-Output Engine Only
The 2 knock sensors are bolted into the cylinder
block under the intake manifold (Fig. 22).
NOTE: The left sensor is identified by an identifica-
tion tag (LEFT). It is also identified by a larger bolt
head. The Powertrain Control Module (PCM) must
have and know the correct sensor left/right posi-
tions. Do not mix the sensor locations.
(1) Disconnect knock sensor dual pigtail harness
connector from engine wiring harness connector. This
connection is made near the right/rear of intake man-
ifold (Fig. 23).
(2) Remove intake manifold. Refer to Engine sec-
tion.
(3) Remove sensor mounting bolts (Fig. 22). Note
foam strip on bolt threads. This foam is used only to
retain the bolts to sensors for plant assembly. It is
not used as a sealant. Do not apply any adhesive,
sealant or thread locking compound to these bolts.
(4) Remove sensors from engine.
Fig. 22 KNOCK SENSOR LOCATION - 4.7L H.O.
1 - KNOCK SENSORS (2)
2 - MOUNTING BOLTS
3 - INTAKE MANIFOLD (CUTAWAY)
4 - PIGTAIL CONNECTOR
Fig. 23 KNOCK SENSOR ELEC. CONNECTOR - 4.7L
H.O.
1 - KNOCK SENSOR PIGTAIL HARNESS CONNECTOR
2 - ENGINE WIRING HARNESS
8I - 14 IGNITION CONTROLWJ
KNOCK SENSOR (Continued)

INSTALLATION
4.7L High-Output Engine Only
NOTE: The left sensor is identified by an identifica-
tion tag (LEFT). It is also identified by a larger bolt
head. The Powertrain Control Module (PCM) must
have and know the correct sensor left/right posi-
tions. Do not mix the sensor locations.
(1) Thoroughly clean knock sensor mounting holes.
(2) Install sensors (Fig. 22) into cylinder block.
NOTE: Over or under tightening the sensor mount-
ing bolts will affect knock sensor performance, pos-
sibly causing improper spark control. Always use
the specified torque when installing the knock sen-
sors. The torque for the knock senor bolt is rela-
tively light for an 8mm bolt.
NOTE: Note foam strip on bolt threads. This foam is
used only to retain the bolts to sensors for plant
assembly. It is not used as a sealant. Do not apply
any adhesive, sealant or thread locking compound
to these bolts.
(3) Install and tighten mounting bolts.Bolt
torque is critical.Refer to torque specification.
(4) Install intake manifold. Refer to Engine sec-
tion.
(5) Connect knock sensor pigtail wiring harness to
engine wiring harness near right / rear of intake
manifold (Fig. 23).
SPARK PLUG
DESCRIPTION
Both the 4.0L 6-cylinder and the 4.7L V-8 engine
use resistor type spark plugs. Standard 4.7L V-8
engines are equipped with ªfired in suppressor sealº
type spark plugs using a copper core ground elec-
trode. High-Output (H.O.) 4.7L V-8 engines are
equipped with unique plugs using a platinum rivet
located on the tip of the center electrode.
Because of the use of an aluminum cylinder head
on the 4.7L engine, spark plug torque is very critical.
To prevent possible pre-ignition and/or mechanical
engine damage, the correct type/heat range/number
spark plug must be used.Do not substitute any
other spark plug on the 4.7L H.O. engine. Seri-
ous engine damage may occur.
Plugs on both engines have resistance values rang-
ing from 6,000 to 20,000 ohms (when checked with at
least a 1000 volt spark plug tester).Do not use an
ohmmeter to check the resistance values of thespark plugs. Inaccurate readings will result.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. A sin-
gle plug displaying an abnormal condition indicates
that a problem exists in the corresponding cylinder.
Replace spark plugs at the intervals recommended in
Group O, Lubrication and Maintenance.
EXCEPT 4.7L H.O. ENGINE :Spark plugs that
have low mileage may be cleaned and reused if not
otherwise defective, carbon or oil fouled. Also refer to
Spark Plug Conditions.4.7L H.O. ENGINE :Never
clean spark plugs on the 4.7L H.O. engine. Damage
to the platinum rivet will result.
CAUTION: EXCEPT 4.7L H.O. ENGINE : Never use a
motorized wire wheel brush to clean the spark
plugs. Metallic deposits will remain on the spark
plug insulator and will cause plug misfire.
H.O. Gap Adjustment:If equipped with the 4.7L
H.O. engine, do not use a wire-type gapping tool as
damage to the platinum rivet on the center electrode
may occur. Use a tapered-type gauge (Fig. 24).
DIAGNOSIS AND TESTING - SPARK PLUG
CONDITIONS
NORMAL OPERATING
The few deposits present on the spark plug will
probably be light tan or slightly gray in color. This is
evident with most grades of commercial gasoline
Fig. 24 PLUG GAP - 4.7L H.O.
1 - TAPER GAUGE
WJIGNITION CONTROL 8I - 15
KNOCK SENSOR (Continued)

Programmable Communications Interface (PCI) data
bus. The SKIS indicator bulb 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 bulb only illuminates when it is switched
to ground by the instrument cluster transistor. The
instrument cluster will turn on the SKIS indicator
for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position, the SKIM tells the cluster
to illuminate the SKIS indicator for about three sec-
onds as a bulb test.
²SKIS Indicator Lamp-On Message- Each
time the cluster receives a SKIS indicator lamp-on
message from the SKIM, the SKIS indicator will be
illuminated. The indicator can be flashed on and off,
or illuminated solid, as dictated by the SKIM mes-
sage. For more information on the SKIS and the
SKIS indicator control parameters, (Refer to 8 -
ELECTRICAL/VEHICLE THEFT SECURITY -
OPERATION). The indicator remains illuminated
until the cluster receives a SKIS indicator lamp-off
message from the SKIM, or until the ignition switch
is turned to the Off position, whichever occurs first.
²Communication Error- If the cluster receives
no SKIS indicator lamp-on or lamp-off messages from
the SKIM for twenty consecutive seconds, the SKIS
indicator is illuminated by the instrument cluster.
The indicator remains controlled and illuminated by
the cluster until a valid SKIS indicator lamp-on or
lamp-off message is received from the SKIM.
²Actuator Test- Each time the cluster is put
through the actuator test, the SKIS indicator will be
turned on for the duration of the test to confirm the
functionality of the bulb and the cluster control cir-
cuitry.
The SKIM performs a self-test each time the igni-
tion switch is turned to the On position to decide
whether the system is in good operating condition
and whether a valid key is present in the ignition
lock cylinder. The SKIM then sends the proper SKIS
indicator lamp-on or lamp-off messages to the instru-
ment cluster. If the SKIS indicator fails to light dur-
ing the bulb test, replace the bulb with a known good
unit. For further diagnosis of the SKIS indicator or
the instrument cluster circuitry that controls the
indicator, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). If the
instrument cluster flashes the SKIS indicator upon
ignition On, or turns on the SKIS indicator solid
after the bulb test, it indicates that a SKIS malfunc-
tion has occurred or that the SKIS is inoperative. Forproper diagnosis of the SKIS, the PCI data bus, or
the electronic message inputs to the instrument clus-
ter that control the SKIS indicator, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
SPEEDOMETER
DESCRIPTION
A speedometer is standard equipment on all instru-
ment clusters. The speedometer is located to the
right of the tachometer in the instrument cluster.
The speedometer consists of a movable gauge needle
or pointer controlled by the instrument cluster cir-
cuitry, and a fixed 255 degree primary scale on the
gauge dial face that reads left-to-right either from 0
to 120 mph, from 0 to 200 km/h, or from 0 to 220
km/h, depending upon the market for which the vehi-
cle is manufactured. Most models also have a smaller
secondary inner scale on the gauge dial face that pro-
vides the equivalent opposite measurement units
from the primary scale. Text appearing in the center
of the gauge dial face just beneath the hub of the
speedometer needle abbreviates the unit of measure
for the primary scale in all upper case letters (i.e.:
MPH or KM/H). On models with a secondary scale,
the abbreviation for that scale follows the abbrevia-
tion for the primary scale in all lower case letters
(i.e.: mph or km/h).
The speedometer graphics are either white, gray
and orange against a black gauge dial face (base
cluster) or black and gray against a taupe gauge dial
face (premium cluster), making them clearly visible
within the instrument cluster in daylight. When illu-
minated 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. The gray gauge graphics for both versions of
the cluster are not illuminated. The orange gauge
needle in the base cluster gauge is internally illumi-
nated, 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
speedometer is serviced as a unit with the instru-
ment cluster.
8J - 30 INSTRUMENT CLUSTERWJ
SKIS INDICATOR (Continued)

²RETRAIN TIRE SENSORS?- This program-
mable feature only applies to vehicles equipped with
the optional tire pressure monitoring system. The
options include Yes and No. The default is No. When
Yes is selected and the menu button is depressed, the
EVIC will enter the training mode starting with the
left front tire.
²EASY EXIT SEAT?- This programmable fea-
ture only applies to vehicles equipped with the
optional memory system. The options include Yes and
No. The default is No. When Yes is selected, the
driver seat moves rearward about 55 millimeters
(two inches) or to the farthest rearward position,
whichever comes first, when the key is removed from
the ignition switch lock cylinder. This provides addi-
tional ease for exiting from the vehicle. The seat will
automatically return to the memory system setting
position when the Driver 1 or Driver 2 button of the
memory switch on the door panel is depressed or, if
theREMOTE LINKED TO MEMORYprogramma-
ble feature is enabled, when the RKE Unlock button
is depressed. While not automatic, an easy entry fea-
ture can be obtained by enabling theEASY EXIT
SEATfeature and disabling theREMOTE LINKED
TO MEMORYfeature. Then theEASY EXIT SEAT
feature will move the seat back, but the RKE unlock
event will not reposition the seat. Thus, the seat
remains positioned for easy entry, and the memory
switch on the door panel can be depressed after
entering the vehicle to return the seat to the desired
memory position.
STANDARD PROCEDURE - COMPASS
DEMAGNETIZING
A degaussing tool (Special Tool 6029) is used to
demagnetize, or degauss, the overhead console for-
ward mounting screw and the roof panel above the
overhead console. Equivalent units must be rated as
continuous duty for 110/115 volts and 60 Hz. They
must also have a field strength of over 350 gauss at 7
millimeters (0.25 inch) beyond the tip of the probe.
To demagnetize the roof panel and the overhead
console forward mounting screw, proceed as follows:
(1) Be certain that the ignition switch is in the Off
position, before you begin the demagnetizing proce-
dure.
(2) Connect the degaussing tool to an electrical
outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.
(3) Slowly approach the head of the overhead con-
sole forward mounting screw with the degaussing
tool connected.
(4) Contact the head of the screw with the plastic
coated tip of the degaussing tool for about two sec-
onds.(5) With the degaussing tool still energized, slowly
back it away from the screw. When the tip of the tool
is at least 61 centimeters (2 feet) from the screw
head, disconnect the tool.
(6) Place a piece of paper approximately 22 by 28
centimeters (8.5 by 11 inches), oriented on the vehicle
lengthwise from front to rear, on the center line of
the roof at the windshield header (Fig. 3). The pur-
pose of the paper is to protect the roof panel from
scratches, and to define the area to be demagnetized.
(7) Connect the degaussing tool to an electrical
outlet, while keeping the tool at least 61 centimeters
(2 feet) away from the compass unit.
(8) Slowly approach the center line of the roof
panel at the windshield header, with the degaussing
tool connected.
(9) Contact the roof panel with the plastic coated
tip of the degaussing tool. Be sure that the template
is in place to avoid scratching the roof panel. Using a
slow, back-and-forth sweeping motion, and allowing
13 millimeters (0.50 inch) between passes, move the
tool at least 11 centimeters (4 inches) to each side of
the roof center line, and 28 centimeters (11 inches)
back from the windshield header.
(10) With the degaussing tool still energized,
slowly back it away from the roof panel. When the
Fig. 3 Roof Demagnetizing Pattern
8M - 4 MESSAGE SYSTEMSWJ
OVERHEAD CONSOLE (Continued)

POWER SYSTEMS
TABLE OF CONTENTS
page page
POWER LOCKS............................ 1
POWER MIRRORS........................ 11POWER SEAT SYSTEM..................... 18
POWER WINDOWS........................ 33
POWER LOCKS
TABLE OF CONTENTS
page page
POWER LOCKS
DESCRIPTION
DESCRIPTION - POWER LOCK SYSTEM....1
DESCRIPTION - REMOTE KEYLESS ENTRY
SYSTEM.............................2
DESCRIPTION - LIFTGATE FLIP-UP GLASS
POWER RELEASE SYSTEM..............4
OPERATION
OPERATION - POWER LOCK SYSTEM......4
OPERATION - REMOTE KEYLESS ENTRY
SYSTEM.............................5
OPERATION - LIFTGATE FLIP-UP GLASS
POWER RELEASE SYSTEM..............5
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER LOCK
SYSTEM.............................5
DIAGNOSIS AND TESTING - REMOTE
KEYLESS ENTRY SYSTEM...............6
DIAGNOSIS AND TESTING - LIFTGATE
FLIP-UP GLASS POWER RELEASE
SYSTEM.............................6
DOOR CYLINDER LOCK SWITCH
DESCRIPTION..........................7OPERATION............................7
POWER LOCK MOTOR
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING - POWER LOCK
MOTOR ..............................8
POWER LOCK SWITCH
DESCRIPTION..........................8
OPERATION............................8
REMOTE KEYLESS ENTRY MODULE
DESCRIPTION..........................9
OPERATION............................9
REMOTE KEYLESS ENTRY TRANSMITTER
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING - REMOTE
KEYLESS ENTRY TRANSMITTER..........9
STANDARD PROCEDURE
STANDARD PROCEDURE - RKE
TRANSMITTER PROGRAMMING..........10
STANDARD PROCEDURE - RKE
TRANSMITTER BATTERIES..............10
POWER LOCKS
DESCRIPTION
DESCRIPTION - POWER LOCK SYSTEM
A power operated door and liftgate lock system is
standard factory-installed equipment on this model.
The power lock system allows all of the doors and the
liftgate to be locked or unlocked electrically by oper-
ating a switch on either front door trim panel. The
power lock system receives non-switched battery feedthrough a fuse in the Power Distribution Center
(PDC), so that the power locks remain operational,
regardless of the ignition switch position.
The power lock system for this vehicle also has a
door lock inhibit feature, which prevents the power
lock system from being energized with a power door
lock switch if a front door is open with the key in the
ignition. However, the locks can still be operated
manually, with a key, energized with the RKE trans-
mitter or by sliding the door lock lever to the appro-
priate position.
WJPOWER SYSTEMS 8N - 1

If not OK, replace the faulty liftgate latch actuator
(brainplate) unit.
(5) Disconnect the liftgate wire harness connector
for the liftgate flip-up glass release switch from the
switch connector receptacle. With the liftgate latch
unlocked, check for battery voltage at the liftgate
flip-up glass limit switch output circuit cavity of the
liftgate wire harness connector for the release switch.
If OK, go to Step 6. If not OK, repair the open lift-
gate flip-up glass limit switch output circuit between
the release switch and the limit switch as required.
(6) Check for continuity between the two terminals
of the liftgate flip-up glass release switch. There
should be no continuity. Depress the switch, there
should now be continuity. If OK, go to Step 7. If not
OK, replace the faulty liftgate flip-up glass release
switch.
(7) Disconnect the liftgate wire harness connector
for the liftgate flip-up glass latch motor from the
motor connector receptacle. Check for continuity
between the ground circuit cavity of the liftgate wire
harness connector for the latch motor and a good
ground. There should be continuity. If OK, go to Step
8. If not OK, repair the open ground circuit to ground
as required.
(8) With the liftgate latch unlocked and the flip-up
glass release switch depressed, check for battery volt-
age at the liftgate flip-up glass release switch output
circuit cavity of the liftgate wire harness connector
for the latch motor. If OK, replace the faulty liftgate
flip-up glass latch unit. If not OK, repair the open
liftgate flip-up glass release switch output circuit
between the latch motor and the release switch as
required.
DOOR CYLINDER LOCK
SWITCH
DESCRIPTION
The driver cylinder lock switch is integral to the
key lock cylinder inside the driver side front door.
The driver cylinder lock switch is a resistive multi-
plexed switch that is hard wired between a body
ground and the Driver Door Module (DDM) through
the front door wire harness. It maintains a path to
ground, and changes voltages through an internal
resistor when the lock cylinder is rotated to the lock
or unlock position.
The driver cylinder lock switch cannot be adjusted
or repaired and, if faulty or damaged, the driver side
front door lock cylinder unit must be replaced. (Refer
to 23 - BODY/DOOR - FRONT/LOCK CYLINDER -
REMOVAL) and (Refer to 23 - BODY/DOOR -
FRONT/LOCK CYLINDER - INSTALLATION). Refer
to the appropriate wiring information. The wiringinformation includes wiring diagrams, proper wire
and connector repair procedures, 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 driver cylinder lock switch is actuated by the
key lock cylinder when the key is inserted in the lock
cylinder and turned to the unlock position. The
driver cylinder lock switch maintains a path to
ground and changes voltages through an internal
resistor for the DDM when the driver door key lock
cylinder is in the lock or unlock position. The DDM
reads the switch status through an internal pull-up,
then sends the proper switch status messages to
other electronic modules over the Programmable
Communications Interface (PCI) data bus network.
The driver cylinder lock switch unlock status mes-
sage is used by the BCM as an input for Vehicle
Theft Security System (VTSS) operation and interior
lighting.
POWER LOCK MOTOR
DESCRIPTION
Power operated front door, rear door, and liftgate
locking mechanisms are standard equipment on this
model. The lock mechanisms are actuated by a
reversible electric motor mounted within each door
and the liftgate. The power lock motors for the doors
are integral to the door latch units. The liftgate
power lock motor is a separate unit secured to the
latch brainplate near the center of the liftgate and
operates the liftgate latch lock mechanism through a
connecting linkage rod.
The power lock motors for the four doors cannot be
adjusted or repaired and, if faulty or damaged, the
entire door latch unit must be replaced. The liftgate
power lock motor cannot be adjusted or repaired and,
if faulty or damaged, the entire liftgate latch actua-
tor (brainplate) unit must be replaced.
OPERATION
The driver side front door power lock motor is con-
trolled by the Driver Door Module (DDM). The
remaining power door lock motors and the liftgate
power lock motor are controlled by the Passenger
Door Module (PDM). A positive and negative battery
connection to the two motor terminals will cause the
power lock motor plunger to move in one direction.
Reversing the current through these same two con-
nections will cause the power lock motor plunger to
move in the opposite direction.
WJPOWER LOCKS 8N - 7
POWER LOCKS (Continued)