Headlamp fuse relay JEEP LIBERTY 2002 KJ / 1.G Owner's Manual

move the headlamps to the selected position based
upon the voltage input received from the switch. The
headlamp leveling motors and switch have a path to
ground at all times. The headlamp leveling compo-
nents operate on battery current received through
the fused park lamp relay output circuit so that the
system will only operate when the exterior lighting is
turned on.
PARK LAMPS
The park lamps system includes the Body Control
Module (BCM), a park lamp relay installed in the
Junction Block (JB), and the exterior lighting switch
integral to the left (lighting) control stalk of the
multi-function switch. The front park lamp and side
marker or, if equipped, the front position lamp bulbs
each have a path to ground at all times through their
connections to the grille opening reinforcement wire
harness from two take outs of the headlamp and
dash wire harness with eyelet terminal connectors
that are secured by ground screws to the left inner
fender shield in the engine compartment. The rear
park lamp bulbs and license plate lamp have a path
to ground at all times through their connection to the
rear lighting wire harness from a take out of the rear
body wire harness with an eyelet terminal connector
that is secured by a ground screw to the base of the
right D-pillar behind the quarter trim panel. The
BCM controls the park lamp operation by monitoring
the exterior lighting switch inputs from the multi-
function switch, then energizing or de-energizing the
control coil of the park lamp relay. When the park
lamp relay is energized, it provides battery current
from a fused B(+) fuse in the Power Distribution
Center (PDC) through a park lamp relay output cir-
cuit and a separate fuse in the JB through a fused
park lamp relay output circuit to the appropriate
lamp bulb filaments. The BCM provides a battery
saver (load shedding) feature for the park lamps,
which will turn these lamps off if they are left on for
more than about eight minutes with the ignition
switch in the Off position.
REAR FOG LAMPS
Rear fog lamps are installed on vehicles manufac-
tured for certain markets where they are required.
The rear fog lamp system includes a premium Body
Control Module (BCM), a rear fog lamp relay
installed in the Junction Block (JB), and a rear fog
lamp switch integral to the left (lighting) control
stalk of the multi-function switch. The rear fog lamps
have a path to ground at all times through their con-
nection to the rear lighting wire harness from a take
out of the rear body wire harness with an eyelet ter-
minal connector that is secured by a ground screw to
the base of the right D-pillar behind the quarter trimpanel. The BCM controls rear fog lamp operation by
monitoring the exterior lighting switch input from
the multi-function switch, then energizing or de-ener-
gizing the rear fog lamp relay control coil; and, by
sending the appropriate electronic message to the
instrument cluster over the Programmable Commu-
nications Interface (PCI) data bus to turn the rear
fog lamp indicator on or off. When the rear fog lamp
relay is energized, it provides battery current from a
fused B(+) fuse in the JB to the rear fog lamps
through the rear fog lamp relay output circuit. The
BCM provides a battery saver (load shedding) feature
for the rear fog lamps, which will turn these lamps
off if they are left on for more than about eight min-
utes with the ignition switch in the Off position.
TURN SIGNAL LAMPS
When the left control stalk of the multi-function
switch is moved up (right turn) or down (left turn),
the turn signal system is activated causing the
selected right or left turn signal indicator, and right
or left turn signal lamps to flash on and off. When
the turn signal system is activated, the circuitry
within the turn signal switch and the hazard switch/
electronic combination flasher unit will repeatedly
energize and de-energize one of two internal relays
that switch battery current from a fused ignition
switch output (run) fuse in the Junction Block (JB) to
the right side or left side turn signal indicators and
turn signal lamps through the right or left turn sig-
nal circuits. The ElectroMechanical Instrument Clus-
ter (EMIC) chime tone generator will generate an
audible turn signal cancel warning each time the
vehicle is driven for a distance of about 3.2 kilome-
ters (about two miles) with a turn signal indicator
flashing. The EMIC uses Programmable Communica-
tions Interface (PCI) data bus distance messages
from the Powertrain Control Module (PCM) and a
hard wired input from the turn signal switch cir-
cuitry of the multi-function switch to determine when
to sound the turn signal cancel warning.
DIAGNOSIS AND TESTING - LAMPS/LIGHTING
- EXTERIOR
The hard wired circuits and components of the
exterior lighting systems may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the Body
Control Module (BCM), the ElectroMechanical
Instrument Cluster (EMIC), the Powertrain Control
Module (PCM), or the Programmable Communica-
tions Interface (PCI) data bus network. The most
reliable, efficient, and accurate means to diagnose
the BCM, the EMIC, the PCM, and the PCI data bus
network inputs and outputs related to the various
KJLAMPS8Ls-7
LAMPS/LIGHTING - EXTERIOR (Continued)

BRAKE LAMPS
CONDITION POSSIBLE CAUSES CORRECTION
BRAKE LAMP DOES NOT
ILLUMINATE1. Faulty or missing fuse. 1. Test and replace brake lamp fuse as
required.
2. Faulty or missing bulb. 2. Test and replace brake lamp bulb as
required.
3. Faulty switch. 3. Test and replace brake lamp switch as
required.
4. Faulty ground circuit. 4. Test and repair brake lamp ground circuit
as required.
5. Faulty feed circuit. 5. Test and repair open brake lamp switch
output circuit as required.
BRAKE LAMP DOES NOT
EXTINGUISH1. Faulty switch. 1. Test and replace brake lamp switch as
required.
2. Faulty feed circuit. 2. Test and repair shorted brake lamp
switch output circuit as required.
DAYTIME RUNNING LAMPS
Before performing the following tests, determine
whether the headlamp low and high beams operate.If the headlamp high and low beams are also inoper-
ative, diagnose and repair that problem before
attempting to repair the Daytime Running Lamps.
CONDITION POSSIBLE CAUSES CORRECTION
DAYTIME RUNNING
LAMPS WILL NOT
ILLUMINATE1. High beam relay installed. 1. Remove high beam relay as required.
2. Faulty or missing DRL relay. 2. Replace DRL relay with a known good
unit and check operation. Replace DRL
relay as required.
3. Incorrect BCM programming. 3. Use a DRBIIITscan tool to check and
program correct country code into BCM as
required.
4. Faulty BCM inputs or outputs. 4. Use a DRBIIITscan tool to test the BCM
inputs or outputs. Refer to the appropriate
diagnostic information.
KJLAMPS8Ls-9
LAMPS/LIGHTING - EXTERIOR (Continued)

HEADLAMPS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMP DOES NOT
ILLUMINATE1. Faulty or missing fuse. 1. Test and replace headlamp fuse as
required.
2. Faulty or missing bulb. 2. Test and replace headlamp bulb as
required.
3. Faulty or missing relay. 3. Test and replace low beam or high beam
relay as required. (Note: Vehicles with a
DRL relay do not use a high beam relay.
The DRL relay cannot be tested. Replace
DRL relay with a known good unit and
check operation. Replace DRL relay as
required.)
4. Faulty switch. 4. Test and replace multi-function switch as
required.
5. Faulty ground circuit. 5. Test and repair open headlamp ground
circuit as required.
6. Faulty feed circuit. 6. Test and repair open headlamp low
beam, high beam, or DRL relay output
circuit as required.
7. Faulty BCM inputs or outputs. 7. Use a DRBIIITscan tool to test the BCM
inputs and outputs. Refer to the appropriate
diagnostic information.
HEADLAMP DOES NOT
EXTINGUISH1. Faulty relay. 1. Test and replace low beam or high beam
relay as required. (Note: Vehicles with a
DRL relay do not use a high beam relay.
The DRL relay cannot be tested. Replace
DRL relay with a known good unit and
check operation. Replace DRL relay as
required.)
2. Faulty switch. 2. Test and replace multi-function switch as
required.
3. Faulty feed circuit. 3. Test and repair shorted headlamp low
beam, high beam, or DRL relay output
circuit as required.
4. Faulty BCM inputs or outputs. 4. Use a DRBIIITscan tool to test the BCM
inputs and outputs. Refer to the appropriate
diagnostic information.
KJLAMPS8Ls-11
LAMPS/LIGHTING - EXTERIOR (Continued)

system. Constant battery voltage is supplied to the
flasher so that it can perform the hazard warning func-
tion, and ignition switched battery voltage is supplied
for the turn signal function. The Integrated Circuit (IC)
within the combination flasher contains the logic that
controls the flasher operation and the flash rate. The
IC receives separate sense ground inputs from the
multi-function switch for the right and left turn sig-
nals, and from the hazard switch contacts or the BCM
for the hazard warning signals. A special design feature
of the combination flasher allows it to9sense9that a
turn signal circuit or bulb is not operating, and provide
the driver an indication of the condition by flashing the
remaining bulbs in the affected circuit at a higher rate
(120 flashes-per-minute or higher). Conventional flash-
ers either continue flashing at their typical rate (heavy-
duty type), or discontinue flashing the affected circuit
entirely (standard-duty type).
Because of the active electronic elements within
the combination flasher, it cannot be tested with con-
ventional automotive electrical test equipment. If the
combination flasher is believed to be faulty, test the
turn signal and hazard warning system. Then
replace the hazard switch with a known good unit to
confirm system operation.
DAYTIME RUNNING LAMP
RELAY
DESCRIPTION
The Daytime Running Lamp (DRL) relay (Fig. 8) is
a solid state relay that is used only on vehicles man-
ufactured for sale in Canada. The DRL relay featuresa die cast aluminum housing with integral cooling
fins that act as a heat sink for the solid state DRL
circuitry. Four male spade terminals extend from the
base of the relay through a potting material that
encloses and protects the DRL circuitry. Although the
DRL relay has four terminals that are laid out in a
footprint that is similar to that of a conventional
International Standards Organization (ISO) relay, a
standard ISO relay should never be installed in place
of the DRL relay. The DRL relay is installed in the
Junction Block (JB) on the driver side outboard end
of the instrument panel. Vehicles equipped with this
relay do not have a headlamp high beam relay
installed in the JB.
The DRL relay cannot be adjusted or repaired and,
if faulty or damaged, the unit must be replaced.
OPERATION
The Daytime Running Lamp (DRL) relay is a solid
state relay that controls the flow of battery current
to the high beam filaments of both headlamp bulbs
based upon a duty cycled control input received from
the Body Control Module (BCM) of vehicles equipped
with the DRL feature. By cycling the DRL relay out-
put, the BCM controls the illumination intensity of
the high beam filaments. The DRL relay terminals
are connected to the vehicle electrical system through
a connector receptacle in the Junction Block (JB).
The inputs and outputs of the DRL relay include:
²Battery Current Input- The DRL relay
receives battery current on a fused B(+) circuit from
a fuse in the Power Distribution Center (PDC).
²Ground Input- The DRL relay receives a path
to ground through a splice block located in the
instrument panel wire harness with an eyelet termi-
nal connector that is secured by a nut to a ground
stud on the driver side instrument panel end bracket
near the Junction Block (JB).
²Control Input- The DRL relay control input is
received from the BCM and/or the momentary optical
horn (flash-to-pass) output of the multi-function
switch through a high beam relay control circuit.
²Control Output- The DRL relay supplies bat-
tery current output to the headlamp high beam fila-
ments through the high beam relay output circuit.
Because of active electronic elements within the
DRL relay, it cannot be tested with conventional
automotive electrical test equipment. If the DRL
relay is believed to be faulty, replace the relay with a
known good unit to confirm system operation.
Fig. 8 Daytime Running Lamp Relay
1 - DRL RELAY
2 - HEAT SINK
3 - POTTING MATERIAL
4 - TERMINAL (4)
8Ls - 20 LAMPSKJ
COMBINATION FLASHER (Continued)

(5) Position the outer circumference of the boot
seal over the flange on the back of the headlamp unit
housing and pull it downward until the seal is fully
engaged over the flange.
(6) Reinstall the headlamp unit onto the grille
opening reinforcement. (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/HEADLAMP UNIT
- INSTALLATION).
(7) Reconnect the battery negative cable.
(8) Confirm proper headlamp unit alignment.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/HEADLAMP UNIT - ADJUSTMENTS).
HEADLAMP HIGH BEAM
RELAY
DESCRIPTION
The headlamp high beam relay is located in the
Junction Block (JB) on the driver side outboard end
of the instrument panel in the passenger compart-
ment of the vehicle. The headlamp high beam relay
is omitted from vehicles manufactured for sale in
Canada, which have a Daytime Running Lamp (DRL)
solid state relay installed in the JB that also per-
forms the function of the headlamp high beam relay.
The headlamp high beam relay is a conventional
International Standards Organization (ISO) micro
relay (Fig. 28). 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 the
required inputs and outputs by five integral male
spade-type terminals that extend from the bottom of
the relay base.
The headlamp high beam relay cannot be adjusted
or repaired and, if faulty or damaged, the unit must
be replaced.
OPERATION
The headlamp high beam relay is an electrome-
chanical switch that uses a low current input from
the Body Control Module (BCM) to control a high
current output to the headlamp high beam filaments.
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 wind-
ings. 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 volt-
age spikes and electromagnetic interference that can
be generated as the electromagnetic field of the relay
coil collapses.
The headlamp high beam relay terminals are con-
nected to the vehicle electrical system through a con-
nector receptacle in the Junction Block (JB). The
inputs and outputs of the headlamp high beam relay
include:
²Common Feed Terminal- The common feed
terminal (30) receives battery current at all times
from a fuse in the Power Distribution Center (PDC)
through a fused B(+) circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Body
Control Module (BCM) through a head lamp relay
control circuit. The BCM controls head lamp opera-
tion by controlling a ground path through this circuit
²Coil Battery Terminal- The coil battery ter-
minal (86) is connected to a control output of the
Body Control Module (BCM) and to the momentary
optical horn (flash-to-pass) output of the multi-func-
tion switch through a high beam relay control circuit.
The BCM and/or the multi-function switch controls
headlamp high beam operation by controlling a
ground path through this circuit.
²Normally Open Terminal- The normally open
terminal (87) is connected to the headlamp high
beam filaments through the high beam relay output
circuit and provides battery current to the headlamp
high beams whenever the relay is energized.
Fig. 28 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJLAMPS8Ls-33
HEADLAMP BULB (Continued)

OPERATION
The controller board and logic circuitry of the
headlamp leveling motor will energize the motor and
extend or retract the motor pushrod through the
integral screw-drive transmission based upon the
voltage signal input received from the resistor multi-
plexed headlamp leveling switch. The ball formation
on the end of the headlamp leveling motor pushrod is
snapped into a socket formation on the back of the
movable reflector within the headlamp unit housing.
The headlamp leveling motors and switch have a
path to ground at all times. The headlamp leveling
components operate on battery current received
through the fused park lamp relay output circuit so
that the system will only operate when the exterior
lighting is turned On.
Because of active electronic elements within the
headlamp leveling motor, it cannot be tested with
conventional automotive electrical test equipment. If
the headlamp leveling motor is believed to be faulty,
replace the motor with a known good unit to confirm
system operation.
REMOVAL
The headlamp leveling motors are integral to the
headlamp units on vehicles manufactured for certain
markets where headlamp leveling is required.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the headlamp bulb from the headlamp
unit housing. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/HEADLAMP BULB -
REMOVAL).
(3) Rotate the headlamp leveling motor on the
back of the headlamp unit housing counterclockwise
about 30 degrees (Fig. 32).
(4) Firmly grasp the motor with one hand while
stabilizing the headlamp unit housing with the other
hand.
(5) Firmly, steadily, and forcefully pull the head-
lamp leveling motor straight away from the back of
the headlamp unit housing to unsnap the ball forma-
tion on the end of the motor pushrod from the socket
on the headlamp unit reflector (Fig. 33).
(6) Remove the headlamp leveling motor and push-
rod from the back of the headlamp unit housing.
INSTALLATION
The headlamp leveling motors are integral to the
headlamp units on vehicles manufactured for certain
markets where headlamp leveling is required.
(1) Position the headlamp leveling motor and
pushrod from to the mounting hole on the back of the
headlamp unit housing.
(2) Insert two fingers through the bulb mounting
hole in the center of the headlamp reflector and pullthe reflector upwards toward the headlamp leveling
motor.
(3) Align the ball formation on the end of the lev-
eling motor pushrod with the socket on the headlamp
unit reflector (Fig. 33).
(4) While continuing to pulling the reflector
toward the motor, firmly, steadily, and forcefully push
the headlamp leveling motor straight into the back of
the headlamp unit housing to snap the ball formation
on the end of the motor pushrod into the socket on
the headlamp unit reflector.
(5) After the pushrod is engaged to the reflector,
remove your fingers from the bulb mounting hole in
Fig. 32 Headlamp Leveling Motor Remove/Install
1 - LEVELING MOTOR
2 - HEADLAMP HOUSING
3 - PUSHROD
Fig. 33 Leveling Motor Pushrod - Typical
1 - REFLECTOR PUSHROD SOCKET
2 - PUSHROD
3 - LEVELING MOTOR
4 - HEADLAMP HOUSING
8Ls - 36 LAMPSKJ
HEADLAMP LEVELING MOTOR (Continued)

the center of the headlamp reflector and thoroughly
clean any fingerprints from the reflector.
(6) Push the mounting flange of the headlamp lev-
eling motor into the mounting hole on the back of
headlamp unit housing unit the motor is firmly
seated (Fig. 32).
(7) Rotate the headlamp leveling motor on the
back of the headlamp unit housing clockwise about
30 degrees.
(8) Reinstall the headlamp bulb into the headlamp
unit housing. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/HEADLAMP BULB -
INSTALLATION).
(9) Reconnect the battery negative cable.
HEADLAMP LEVELING
SWITCH
DESCRIPTION
The headlamp leveling switch (Fig. 34) is used only
on vehicles manufactured for certain markets where
the headlamp leveling system is required. The head-
lamp leveling switch is mounted in the driver side
inboard trim bezel on the instrument panel, where it
is secured by molded latch features that are integral
to the switch housing. Only the switch bezel and
thumbwheel are visible on the outer surface of the
instrument panel trim bezel. The black plastic switch
thumbwheel is marked with white numbers ª0,º ª1,º
ª2,º and ª3,º each of which indicates one of the four
switch detent positions. Each higher number repre-sents a lower aiming position of the headlamp beam
relative to the road surface. The black, molded plas-
tic switch housing has an integral connector recepta-
cle on the back, a single latch feature on the top, and
two latch features (one on each side) on the bottom.
The switch is connected to the vehicle electrical sys-
tem through a dedicated take out and connector of
the instrument panel wire harness. Within the
switch housing is the leveling switch circuitry includ-
ing the switch contacts and a series resistor configu-
ration.
The headlamp leveling switch cannot be adjusted
or repaired and, if faulty or damaged, the unit must
be replaced.
OPERATION
The headlamp leveling switch receives battery cur-
rent on a fused park lamp relay output circuit from a
fuse in the Junction Block (JB) whenever the park
lamp relay is energized (park lamps are turned On).
The switch receives a path to 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 JB. The only output from
the switch is a voltage signal that it provides to the
headlamp leveling motors on a headlamp adjust sig-
nal circuit. Each switch position selects a different
tap on a series resistor within the switch to provide a
different voltage signal to the leveling motors. The
higher the switch position number, the higher the
output voltage level.
The headlamp leveling switch can be tested using
conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - HEADLAMP
LEVELING SWITCH
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.
Fig. 34 Headlamp Leveling Switch
1 - SWITCH
2 - UPPER LATCH FEATURE (1)
3 - CONNECTOR RECEPTACLE
4 - LOWER LATCH FEATURE (2)
5 - THUMBWHEEL
KJLAMPS8Ls-37
HEADLAMP LEVELING MOTOR (Continued)

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) From the face of the driver side inboard bezel,
align the headlamp leveling switch housing to the
mounting hole in the bezel (Fig. 36).
(2) Push the headlamp leveling switch into the
mounting hole until it is fully seated and the upper
latch and two lower latch features on the switch
housing are engaged on the back of the bezel.
(3) Position the switch and bezel unit to the
instrument panel.
(4) Reconnect the instrument panel wire harness
connector for the headlamp leveling switch to the
switch connector receptacle.
(5) Reinstall the driver side inboard bezel onto the
instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/INSTRUMENT PANEL DRIVER
SIDE BEZEL - INSTALLATION).
(6) Reconnect the battery negative cable.
HEADLAMP LOW BEAM RELAY
DESCRIPTION
The headlamp low beam relay is located in the
Junction Block (JB) below the driver side outboard
end of the instrument panel in the passenger com-
partment of the vehicle. The headlamp low beam
relay is a conventional International Standards
Organization (ISO) micro relay (Fig. 37). Relays con-
forming to the ISO specifications have common phys-
ical dimensions, current capacities, terminal
patterns, and terminal functions. The relay is con-
tained within a small, rectangular, molded plastic
housing and is connected to all of the required inputs
and outputs by five integral male spade-type termi-
nals that extend from the bottom of the relay base.
The headlamp low beam relay cannot be adjusted
or repaired and, if faulty or damaged, the unit must
be replaced.
OPERATION
The headlamp low beam relay is an electromechan-
ical switch that uses a low current input from the
Body Control Module (BCM) to control a high current
output to the headlamp low beam filaments. 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 electro-
magnetic field is produced by the coil windings. This
electromagnetic field draws the movable relay con-
tact point away from the fixed normally closed con-
tact point, and holds it against the fixed normally
open contact point. When the relay coil is de-ener-
gized, 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 headlamp low beam relay terminals are con-
nected to the vehicle electrical system through a con-
nector receptacle in the Junction Block (JB). The
inputs and outputs of the headlamp low beam relay
include:
²Common Feed Terminal- The common feed
terminal (30) receives battery current at all times
from a fuse in the Power Distribution Center (PDC)
through a fused B(+) circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) receives battery current at all times from a
fuse in the PDC through a fused B(+) circuit.
Fig. 37 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJLAMPS8Ls-39
HEADLAMP LEVELING SWITCH (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)

²Headlamp Optical Horn- The left (lighting)
control stalk of the multi-function switch is pulled
towards the steering wheel to just before a detent, to
momentarily activate the headlamp optical horn fea-
ture. The high beams will remain illuminated until
the control stalk is released. The multi-function
switch provides a ground output on a high beam
relay control circuit to energize the headlamp high
beam relay (Daytime Running Lamp relay in Cana-
dian vehicles) in the Junction Block (JB) as required.
²Interior Lamps Defeat- The control ring on
the multi-function switch left (lighting) control stalk
is rotated to a full rearward (clockwise) detent to
defeat the illumination of all interior courtesy lamps.
The multi-function switch provides a resistor multi-
plexed output to the Body Control Module (BCM) on
a panel lamps dimmer switch mux circuit, and the
BCM responds by de-energizing its internal courtesy
lamp driver circuit.
²Interior Lamps On- The control ring on the
multi-function switch left (lighting) control stalk is
rotated to a full forward (counterclockwise) detent to
illuminate all interior courtesy lamps. The multi-
function switch provides a resistor multiplexed out-
put to the Body Control Module (BCM) on a panel
lamps dimmer switch mux circuit, and the BCM
responds by energizing its internal courtesy lamp
driver circuit.
²Panel Lamps Dimming- The control ring on
the multi-function switch left (lighting) control stalk
is rotated to one of six minor intermediate detents to
simultaneously select the desired illumination inten-
sity of all adjustable instrument panel and instru-
ment cluster lighting. The control ring is rotated
rearward (clockwise) to dim, or forward (counter-
clockwise) to brighten. The multi-function switch pro-
vides a resistor multiplexed output to the Body
Control Module (BCM) on a panel lamps dimmer
switch mux circuit, and the BCM responds by send-
ing an electronic panel lamps dimming level message
to the ElectroMechanical Instrument Cluster (EMIC)
over the Programmable Communications Interface
(PCI) data bus. The EMIC electronic circuitry then
provides the proper PWM output to the cluster illu-
mination lamps and the VFD on the EMIC circuit
board, then provides a matching PWM output on the
hard wired fused panel lamps dimmer switch signal
circuit.
²Parade Mode- The control ring on the multi-
function switch left (lighting) control stalk is rotated
to an intermediate detent that is one detent rear-
ward (clockwise) from the full forward (counterclock-
wise) detent to select the Parade mode. The multi-
function switch provides a resistor multiplexed
output to the Body Control Module (BCM) on a panel
lamps dimmer switch mux circuit, and the BCMresponds by sending an electronic panel lamps dim-
ming level message to the ElectroMechanical Instru-
ment Cluster (EMIC) over the Programmable
Communications Interface (PCI) data bus. The EMIC
electronic circuitry then provides the proper PWM
output to the cluster illumination lamps and the
VFD on the EMIC circuit board, then provides a
matching PWM output on the hard wired fused panel
lamps dimmer switch signal circuit to illuminate all
lamps at full (daylight) intensity with the exterior
lamps turned On.
²Park Lamps- The control knob on the end of
the multi-function switch left (lighting) control stalk
is rotated forward (counterclockwise) to its first
detent from the Off position to activate the park
lamps. 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
park lamp relay in the Junction Block (JB) as
required.
²Rear Fog Lamps- For vehicles so equipped,
the control knob on the end of the multi-function
switch left (lighting) control stalk is rotated forward
(counterclockwise) to its third detent position to acti-
vate the rear fog lamps. 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 rear fog lamp relay in the Junction
Block (JB) as required. Rear fog lamps are optional
only for vehicles manufactured for certain markets,
where they are required.
²Turn Signal Control- The left (lighting) con-
trol stalk of the multi-function switch is moved
upward to activate the right turn signal circuitry,
and, downward to activate the left turn signal cir-
cuitry. The turn signal switch has a detent position
in each direction that provides turn signals with
automatic cancellation, and an intermediate, momen-
tary position in each direction that provides turn sig-
nals only until the left multi-function switch control
stalk is released. When the control stalk is moved to
a turn signal switch detent position, the cancel
actuator extends toward the center of the steering
column. A turn signal cancel cam that is integral to
the clockspring rotates with the steering wheel and
the cam lobes contact the cancel actuator when it is
extended from the left multi-function switch. When
the steering wheel is rotated during a turning
maneuver, one of the two turn signal cancel cam
lobes will contact the turn signal cancel actuator. The
cancel actuator latches against the cancel cam rota-
tion in the direction opposite that which is signaled.
In other words, if the left turn signal detent is
selected, the lobes of the cancel cam will ratchet past
KJLAMPS8Ls-49
MULTI-FUNCTION SWITCH (Continued)