2002 JEEP LIBERTY ECU

(2) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(3) Remove the headlamp low beam relay by
grasping it firmly and pulling it straight out from the
receptacle in the Junction Block (JB) (Fig. 39).
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Position the headlamp low beam relay to the
proper receptacle in the Junction Block (JB) (Fig. 39).
(2) Align the headlamp low beam relay terminals
with the terminal cavities in the JB receptacle.
(3) Push firmly and evenly on the top of the head-
lamp low beam relay until the terminals are fully
seated in the terminal cavities in the JB receptacle.
(4) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(5) Reconnect the battery negative cable.
HEADLAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the grille panel from the grille opening
reinforcement. (Refer to 23 - BODY/EXTERIOR/
GRILLE - REMOVAL).
(3) Remove the two screws that secure the mount-
ing tabs on the inboard side of the headlamp unit
housing to the grille opening reinforcement (Fig. 40).Fig. 39 Junction Block - Inboard Side (LHD Shown -
Rotate 180É for RHD)
1 - PASSENGER DOOR UNLOCK RELAY
2 - JB C3 CONNECTOR RECEPTACLE
3 - LOW BEAM RELAY
4 - CIRCUIT BREAKER #1
5 - CIRCUIT BREAKER #2
6 - CIRCUIT BREAKER #3
7 - DOOR LOCK RELAY
8 - DEFOGGER RELAY
9-SPARE
10 - FRONT FOG LAMP RELAY
11 - HORN RELAY
12 - SPARE
13 - SPARE
14 - REAR FOG LAMP RELAY
15 - PARK LAMP RELAY
16 - DRIVER DOOR UNLOCK RELAY
17 - JB C1 CONNECTOR RECEPTACLE
18 - JB C2 CONNECTOR RECEPTACLE
Fig. 40 Headlamp Unit Remove/Install
1 - FENDER PANEL
2 - HEADLAMP UNIT
3 - MOUNTING TAB (2)
4 - MOUNTING PANEL
5 - LOCATOR TAB
KJLAMPS8Ls-41
HEADLAMP LOW BEAM RELAY (Continued)

(4) Pull the inboard side of the headlamp unit
away from the grille opening reinforcement far
enough to disengage the locator tab on the outboard
side of the unit (Fig. 41) or (Fig. 42) from the engage-
ment slot in the outboard edge of the reinforcement.(5) Pull the headlamp unit away from the grille
opening reinforcement far enough to disconnect the
wire harness connectors from the headlamp bulb
socket (North America), the headlamp bulb base
(Rest-Of-World), the front position lamp socket (if
equipped), and the headlamp leveling motor (if
equipped).
(6) Remove the headlamp unit from the grille
opening reinforcement.
INSTALLATION
(1) Position the headlamp unit to the grille open-
ing reinforcement.
(2) Reconnect the wire harness connectors to the
headlamp bulb socket (North America), the headlamp
bulb base (Rest-Of-World), the front position lamp
socket (if equipped), and the headlamp leveling motor
(if equipped) (Fig. 41) or (Fig. 42).
(3) Engage the locator tab on the outboard side of
the headlamp unit into the engagement slot in the
outboard edge of the grille opening reinforcement.
(4) Align the two mounting tabs on the inboard
side of the headlamp unit housing to the mounting
holes in the grille opening reinforcement (Fig. 40).
(5) Install and tighten the two screws that secure
the mounting tabs on the inboard side of the head-
lamp unit housing to the grille opening reinforce-
ment. Tighten the screws to 3 N´m (30 in. lbs.).
(6) Reinstall the grille panel onto the grille open-
ing reinforcement. (Refer to 23 - BODY/EXTERIOR/
GRILLE - INSTALLATION).
(7) Reconnect the battery negative cable.
(8) Confirm proper headlamp unit alignment.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/HEADLAMP UNIT - ADJUSTMENTS).
ADJUSTMENTS
ADJUSTMENT - HEADLAMP UNIT
VEHICLE PREPARATION FOR HEADLAMP ALIGNMENT
(1) Verify headlamp dimmer (multi-function)
switch and high beam indicator operation.
(2) If the vehicle is equipped with headlamp level-
ing, be certain that the headlamp leveling switch is
in the ª0º position.
(3) Repair or replace any faulty or damaged com-
ponents that could hinder proper lamp alignment.
(4) Verify proper tire inflation.
(5) Clean headlamp lenses.
(6) Verify that cargo area is not heavily loaded.
(7) The fuel tank should be Full. Add 2.94 kilo-
grams (6.5 pounds) of weight over the fuel tank for
each estimated gallon of missing fuel.
Fig. 41 Headlamp Unit - North America
1 - MOUNTING TAB (2)
2 - ADJUSTING SCREW
3 - LOCK RING
4 - HOUSING
5 - LOCATOR TAB
6 - SOCKET & BULB
Fig. 42 Headlamp Unit - Rest-Of-World
1 - LEVELING MOTOR (IF EQUIPPED)
2 - BOOT SEAL
3 - ADJUSTING SCREW
4 - LOCATOR TAB
5 - HOUSING
6 - FRONT POSITION LAMP SOCKET & BULB
7 - HEADLAMP BULB
8 - MOUNTING TAB (2)
8Ls - 42 LAMPSKJ
HEADLAMP UNIT (Continued)

below the headlamp horizontal centerline for vehicles
in North America, or from just below horizontal to
125 millimeters (5 inches) below the headlamp hori-
zontal centerline for vehicles in Rest-Of-World.
(4) Repeat the adjustment procedure for the oppo-
site headlamp.
LICENSE PLATE LAMP BULB
REMOVAL
NORTH AMERICA
(1) Disconnect and isolate the battery negative
cable.
(2) Reach through the opening in the rear bumper
fascia between the license plate and the lamp to
access and firmly grasp the socket on the back of the
license plate lamp unit housing (Fig. 45).
(3) Pull the socket and bulb straight out of the
back of the license plate lamp unit housing.
(4) Pull the bulb straight out of the license plate
lamp unit socket.
REST-OF-WORLD
(1) Disconnect and isolate the battery negative
cable.
(2) Unsnap and lift up the bottom of the license
mounting plate far enough to access and remove the
two screws that secure the license plate bracket to
the special lug nuts on the spare tire (Fig. 46).
(3) Swing the license plate bracket away from the
spare tire far enough to access the license plate lamp
bulb sockets.(4) Firmly grasp the socket on the top of the
license plate lamp unit housing for the bulb that is
being removed (Fig. 47).
(5) Rotate the socket on the top of the license plate
lamp unit housing counterclockwise about 30
degrees.
(6) Pull the socket and bulb straight out of the top
of the license plate lamp unit housing.
(7) Pull the bulb straight out of the license plate
lamp unit socket.
Fig. 44 Headlamp Adjusting Screw
1 - HEADLAMP UNIT
2 - FENDER PANEL
3 - ADJUSTING SCREW ACCESS HOLE
4 - UPPER RADIATOR CROSSMEMBER
Fig. 45 License Plate Lamp Bulb Remove/Install -
North America
1 - REAR BUMPER FASCIA
2 - LICENSE PLATE LAMP
3 - SOCKET
4 - BULB
Fig. 46 License Plate Bracket - Rest-Of-World
1 - SPARE TIRE
2 - SPECIAL LUG NUT (2)
3 - LICENSE PLATE BRACKET
4 - SCREW (2)
8Ls - 44 LAMPSKJ
HEADLAMP UNIT (Continued)

INSTALLATION
CAUTION: Always use the correct bulb size and
type for replacement. An incorrect bulb size or type
may overheat and cause damage to the lamp, the
socket and/or the lamp wiring.
NORTH AMERICA
(1) Align the base of the bulb with the receptacle
in the license plate lamp unit socket.
(2) Push the bulb straight into the license plate
lamp unit socket until it is firmly seated.
(3) Reach through the opening in the rear bumper
fascia between the license plate and the lamp to
align the socket and bulb with the socket opening on
the back of the lamp unit housing (Fig. 45).
(4) Push the socket and bulb straight into the
license plate lamp unit housing until it is firmly
seated.
(5) Reconnect the battery negative cable.
REST-OF-WORLD
(1) Align the base of the bulb with the receptacle
in the license plate lamp unit socket.
(2) Push the bulb straight into the license plate
lamp unit socket until it is firmly seated.
(3) Align the socket and bulb with the socket open-
ing on the top of the license plate lamp unit housing
(Fig. 47).
(4) Push the socket and bulb straight into the
license plate lamp unit housing until it is firmly
seated.(5) Rotate the socket on the top of the license plate
lamp unit housing clockwise about 30 degrees.
(6) Swing the license plate bracket back against
the spare tire (Fig. 46).
(7) Lift up the bottom of the license mounting
plate far enough to install and tighten the two
screws that secure the license plate bracket to the
special lug nuts on the spare tire. Tighten the screws
to 28 N´m (21 ft. lbs.).
(8) Lower the bottom of the license mounting plate
and, using hand pressure, snap it into place on the
license plate bracket.
(9) Reconnect the battery negative cable.
LICENSE PLATE LAMP UNIT
REMOVAL
NORTH AMERICA
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the two screws that secure the license
plate lamp unit to the rear bumper fascia (Fig. 48).
(3) Pull the license plate lamp unit down and out
through the mounting hole in the rear bumper fascia
far enough to access and disconnect the wire harness
connector for the lamp socket pigtail wire.
(4) Remove the license plate lamp unit from the
rear bumper fascia.
Fig. 47 License Plate Lamp Bulb Remove/Install -
Rest-Of-World
1 - LAMP UNIT (2)
2 - LICENSE PLATE BRACKET
3 - SCREW (4)
4 - BULB & SOCKET (2)
Fig. 48 License Plate Lamp Unit Remove/Install
1 - REAR BUMPER FASCIA
2 - LICENSE PLATE LAMP UNIT
3 - SCREW (2)
KJLAMPS8Ls-45
LICENSE PLATE LAMP BULB (Continued)

REST-OF-WORLD
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the bulb and socket unit from the
license plate lamp unit housing that is being
removed. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/LICENSE PLATE LAMP BULB -
REMOVAL - REST-OF-WORLD).
(3) Remove the two screws that secure the license
plate lamp unit to the back of the license plate
bracket (Fig. 49).
(1) Remove the license plate lamp unit from the
back of the license plate bracket.
INSTALLATION
NORTH AMERICA
(1) Position the license plate lamp unit to the rear
bumper fascia.
(2) Reconnect the wire harness connector for the
license plate lamp unit to the lamp socket pigtail
wire.
(3) Position the license plate lamp unit into the
mounting hole in the rear bumper fascia (Fig. 48).
(4) Install and tighten the two screws that secure
the license plate lamp unit housing to the rear
bumper fascia. Tighten the screws to 2 N´m (20 in.
lbs.).
(5) Reconnect the battery negative cable.REST-OF-WORLD
(1) Position the license plate lamp unit onto the
back of the license plate bracket (Fig. 49).
(2) Install and tighten the two screws that secure
the license plate lamp unit to the back of the license
plate bracket. Tighten the screws to 2 N´m (20 in.
lbs.).
(3) Reinstall the bulb and socket unit into the
license plate lamp unit housing that is being
replaced. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/LICENSE PLATE LAMP BULB -
INSTALLATION - REST-OF-WORLD).
(4) Reconnect the battery negative cable.
MULTI-FUNCTION SWITCH
DESCRIPTION
The multi-function switch is located on the steering
column, just below the steering wheel (Fig. 50). The
only visible components of the multi-function switch
are two levers, or control stalks that extend through
dedicated openings in each side of the steering col-
umn shrouds. The remainder of the switch, its
mounting provisions, and its electrical connections
are all concealed beneath the steering column
shrouds. The switch housing and controls are con-
structed of molded black plastic. A saddle-like forma-
tion in the center of the multi-function switch
housing straddles the steering column tube just
below the column lock housing, and two posts inte-
gral to the lower surface of the switch housing
engage two holes on the forward-facing side of the
lock housing. Two integral ledge-like locating tabs
near the top of the rearward facing switch housing
surface are supported and located by two upright
stanchions that extend upward from the top of the
lock housing. Also on the rearward facing switch
housing surface near the center, an integral ledge-
like mounting tab rests on a similar ledge-like tab
that extends from each side of the steering column
lock housing. When the steering column shrouds are
installed on the column, the switch mounting tabs
are clamped along with the mounting tabs of the
clockspring between the integral mounting stan-
chions of the upper shroud and the lock housing tabs,
and are secured to the steering column lock housing
by the same two screws that secure the two shroud
halves to each other and the column.
There are several versions of the multi-function
switch to support both optional equipment and equip-
ment that is required only in certain markets. Each
multi-function switch control stalk has both white
nomenclature and International Control and Display
Symbol graphics applied to it, which clearly identify
its many functions. Each control stalk has a control
Fig. 49 License Plate Lamp Bulb Remove/Install -
Rest-Of-World
1 - LAMP UNIT (2)
2 - LICENSE PLATE BRACKET
3 - SCREW (4)
4 - BULB & SOCKET (2)
8Ls - 46 LAMPSKJ
LICENSE PLATE LAMP UNIT (Continued)

²Parade Mode- The internal circuitry and hard-
ware of the multi-function switch left (lighting) con-
trol stalk provide detent switching for a parade mode
that maximizes the illumination intensity of all
instrument panel lighting for visibility when driving
in daylight with the exterior lamps turned on.
²Park Lamps- The internal circuitry and hard-
ware of the multi-function switch left (lighting) con-
trol stalk provide detent switching for the park
lamps.
²Rear Fog Lamps- For vehicles so equipped,
the internal circuitry and hardware of the multi-
function switch left (lighting) control stalk provide
detent switching for the optional rear fog lamps.
Rear fog lamps are optional only for vehicles manu-
factured for certain markets, where they are
required.
²Turn Signal Control- The internal circuitry
and hardware of the multi-function switch left (light-
ing) control stalk provide both momentary non-detent
switching and detent switching with automatic can-
cellation for both the left and right turn signal
lamps.
RIGHT CONTROL STALK The right (wiper) con-
trol stalk of the multi-function switch supports the
following functions and features:
²Continuous Front Wipe Modes- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide two continuous
front wipe switch positions, low speed or high speed.
²Continuous Rear Wipe Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide one continuous
rear wipe switch position.
²Front Washer Mode- The internal circuitry
and hardware of the multi-function switch right
(wiper) control stalk switch provide front washer sys-
tem operation.
²Front Wipe-After-Wash Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide a wipe-after-wash
mode.
²Front Wiper Mist Mode- The internal cir-
cuitry and hardware of the multi-function switch
right (wiper) control stalk provide a front wiper sys-
tem mist mode.
²Intermittent Front Wipe Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide an intermittent
front wipe mode with five delay interval positions.
²Intermittent Rear Wipe Mode- The internal
circuitry and hardware of the multi-function switch
right (wiper) control stalk provide one fixed interval
intermittent rear wipe mode switch position.²Rear Washer Mode- The internal circuitry and
hardware of the multi-function switch right (wiper)
control stalk provide rear washer system operation.
OPERATION
The multi-function switch uses a combination of
resistor multiplexed and conventionally switched out-
puts to control the many functions and features it
provides. The switch receives battery current on a
fused ignition switch output (run-acc) circuit from a
fuse in the Junction Block (JB) whenever the ignition
switch is in the On or Accessory positions. The switch
receives a path to ground at all times through a
splice block located in the instrument panel wire har-
ness with an eyelet terminal connector that is
secured by a nut to a ground stud on the driver side
instrument panel end bracket near the Junction
Block (JB). Following are descriptions of how each of
the two multi-function switch control stalks operate
to control the functions and features they provide.
LEFT CONTROL STALK The left (lighting) control
stalk of the multi-function switch operates as follows:
²Front Fog Lamps- For vehicles so equipped,
the control knob on the end of the multi-function
switch left (lighting) control stalk is pulled outward
to activate the optional front fog lamps. The control
knob is mechanically keyed so that it cannot be
pulled outward unless it is first rotated to turn on
the exterior lighting. The multi-function switch pro-
vides a resistor multiplexed output to the Body Con-
trol Module (BCM) on a fog lamp switch sense
circuit, and the BCM responds by energizing or de-
energizing the front fog lamp relay in the Junction
Block (JB) as required.
²Headlamps-
The control knob on the end of the
multi-function switch left (lighting) control stalk is
rotated forward (counterclockwise) to its second detent
position to activate the headlamps. The multi-function
switch provides a resistor multiplexed output to the
Body Control Module (BCM) on a headlamp switch
sense circuit, and the BCM responds by energizing or
de-energizing the selected low or high beam relay
(Daytime Running Lamp relay in Canadian vehicles)
in the Junction Block (JB) as required.
²Headlamp Beam Selection-The left (lighting)
control stalk of the multi-function switch is pulled
towards the steering wheel past a detent to actuate
the integral beam select switch circuitry. Each time the
control stalk is activated in this manner, the opposite
headlamp beam from what is currently selected will be
energized. The multi-function switch provides a ground
output to the Body Control Module (BCM) on a high
beam switch sense circuit, and the BCM responds by
energizing or de-energizing the selected low or high
beam relay (Daytime Running Lamp relay in Canadian
vehicles) in the Junction Block (JB) as required.
8Ls - 48 LAMPSKJ
MULTI-FUNCTION SWITCH (Continued)

(4) If the multi-function switch fails any of the
continuity or resistance tests, replace the faulty
switch unit as required.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) If the vehicle is equipped with the optional tilt
steering column, move the tilt steering column to the
fully lowered position and leave the tilt release lever
in the released (down) position.
(3) From below the steering column, remove the
two screws that secure the lower shroud to the upper
shroud (Fig. 52).
(4) Using hand pressure, push gently inward on
both sides of the upper shroud near the parting line
between the upper and lower shrouds to release the
snap features that secure the two halves to each
other.
(5) Remove both the upper and lower shrouds from
the steering column.
(6) Disconnect the two instrument panel wire har-
ness connectors for the multi-function switch from
the two connector receptacles on the back of the
switch housing.
(7) Remove the multi-function switch from the
steering column lock housing by carefully rocking the
switch and pulling the switch housing upward far
enough to disengage its alignment posts and locator
tabs from the lock housing.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
CAUTION: Before attempting to install the multi-
function switch, be certain that the left control stalk
is in the neutral turn signal position and the turn
signal cancel actuator is in the retracted (neutral)
position.
(1) Position the multi-function switch to the steer-
ing column.
(2) Reconnect the two instrument panel wire har-
ness connectors for the multi-function switch to the
two connector receptacles on the back of the switch
housing (Fig. 52).
Fig. 52 Multi-Function Switch Remove/Install
1 - UPPER SHROUD
2 - MULTI-FUNCTION SWITCH
3 - CLOCKSPRING
4 - LOWER SHROUD
5 - SCREW (2)
6 - STEERING COLUMN
7 - WIRE HARNESS CONNECTOR (2)
KJLAMPS8Ls-53
MULTI-FUNCTION SWITCH (Continued)

(3) Position the multi-function switch onto the
steering column lock housing. Be certain that the
switch alignment posts and locator tabs are fully
seated on the lock housing.
(4) Position the upper and lower shrouds onto the
steering column.
(5) Align the snap features on the lower shroud
with the receptacles on the upper shroud and apply
hand pressure to snap them together.
(6) From below the steering column, install and
tighten the two screws that secure the lower shroud
to the upper shroud. Tighten the screws to 2 N´m (20
in. lbs.).
(7) If the vehicle is equipped with the optional tilt
steering column, move the tilt steering column back
to the fully raised position and move the tilt release
lever into the locked (up) position.
(8) Reconnect the battery negative cable.
PARK LAMP RELAY
DESCRIPTION
The park lamp relay is located in the Junction
Block (JB) below the driver side outboard end of the
instrument panel in the passenger compartment of
the vehicle. The park lamp relay is a conventional
International Standards Organization (ISO) micro
relay (Fig. 53). Relays conforming to the ISO specifi-
cations have common physical dimensions, current
capacities, terminal patterns, and terminal functions.
The relay is contained within a small, rectangular,
molded plastic housing and is connected to all of therequired inputs and outputs by five integral male
spade-type terminals that extend from the bottom of
the relay base.
The park lamp relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The park lamp relay is an electromechanical
switch that uses a low current input from the Body
Control Module (BCM) to control a high current out-
put to the park lamps. The movable common feed
contact point is held against the fixed normally
closed contact point by spring pressure. When the
relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The park lamp relay terminals are connected to
the vehicle electrical system through a connector
receptacle in the Junction Block (JB). The inputs and
outputs of the park lamp relay include:
²Common Feed Terminal- The common feed
terminal (30) is connected to the park lamps through
the park lamp relay output circuit and provides
ground to the park lamps when the relay is de-ener-
gized, and battery current to the park lamps when-
ever the relay is energized.
²Coil Ground Terminal-
The coil ground termi-
nal (85) is connected to a control output of the Body
Control Module (BCM) through a park lamp relay con-
trol circuit. The BCM controls park lamp operation by
controlling a ground path through this circuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a fuse in the PDC through a fused B(+) circuit.
²Normally Open Terminal- The normally open
terminal (87) receives battery current at all times
from a fuse in the Power Distribution Center (PDC)
through a fused B(+) circuit.
²Normally Closed Terminal- The normally
closed terminal (87A) is connected to ground at all
times through a ground circuit that receives ground
through a splice block located in the instrument
panel wire harness with an eyelet terminal connector
that is secured by a nut to a ground stud on the
driver side instrument panel end bracket near the
Junction Block (JB).
Fig. 53 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
8Ls - 54 LAMPSKJ
MULTI-FUNCTION SWITCH (Continued)