2002 JEEP LIBERTY Workshop Manual

BRAKE LAMP SWITCH
DESCRIPTION
The brake lamp switch is a three circuit, spring-
loaded plunger actuated switch that is secured to the
steering column support bracket under the driver
side of the instrument panel (Fig. 3). The brake lamp
switch is contained within a rectangular molded plas-
tic housing with an integral connector receptacle fea-
turing six terminal pins and a red plastic Connector
Position Assurance (CPA) lock. The switch is con-
nected to the vehicle electrical system through a ded-
icated take out and connector of the instrument
panel wire harness. The switch plunger extends
through a mounting collar on one end of the switch
housing. The plunger has a one time telescoping self-
adjustment feature that is achieved after the switch
is installed by moving an adjustment release lever on
the opposite end of the switch housing clockwise,
until it locks in a position that is parallel to the con-
nector receptacle. The brake lamp switch self-adjust-
ment is a one time feature. Once the feature has
been used, the switch cannot be readjusted. A ªDO
NOT RE-INSTALLº warning is molded into the
switch housing below the connector receptacle.
An installed brake lamp switch cannot be read-
justed or repaired. If the switch is damaged, faulty,
or removed from its mounting position for any rea-
son, it must be replaced with a new unit.
OPERATION
The brake lamp switch controls three different cir-
cuits, one normally open and two normally closed.
These circuits are described as follows:
²Brake Lamp Switch Circuit- A normally
open brake lamp switch circuit receives battery cur-
rent on a fused B(+) circuit from a fuse in the Junc-
tion Block (JB), and supplies battery current to the
brake lamps and the Controller Antilock Brake
(CAB) on a brake lamp switch output circuit when
the brake pedal is depressed (brake lamp switch
plunger released).
²Brake Lamp Switch Signal Circuit- A nor-
mally closed brake lamp switch signal circuit 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). This circuit supplies a
ground input to the Powertrain Control Module
(PCM) on a brake lamp switch sense circuit when the
brake pedal is released (brake lamp switch plunger is
depressed).
²Speed Control Circuit- A normally closed
speed control circuit receives battery current from
the Powertrain Control Module on a speed control
supply circuit, and supplies battery current to the
speed control servo solenoids (dump, vacuum, and
vent) on a speed control brake switch output circuit
when the speed control system is turned on and the
brake pedal is released (brake lamp switch plunger is
depressed).
Concealed within the brake lamp switch housing
the components of the self-adjusting brake switch
plunger consist of a two-piece telescoping plunger, a
split plunger locking collar, and a release wedge. The
release lever has an integral shaft with a wedge that
spreads the plunger locking collar to an open or
released position. After the switch is installed and
the brake pedal is released, the plunger telescopes to
the correct adjustment position. When the release
lever is moved to the release position, the wedge is
disengaged from the locking collar causing the collar
to apply a clamping pressure to the two plunger
halves fixing the plunger length.
The brake lamp switch can be diagnosed using con-
ventional diagnostic tools and methods.
Fig. 3 Brake Lamp Switch
1 - CONNECTOR RECEPTACLE
2 - BRAKE LAMP SWITCH
3 - PLUNGER
4 - COLLAR
5 - LEVER
8L - 16 LAMPS/LIGHTING - EXTERIORKJ

DIAGNOSIS AND TESTING - BRAKE LAMP
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.
(1) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the brake lamp switch from the switch
connector receptacle.
(2) Using an ohmmeter, perform the continuity
tests at the terminal pins in the brake lamp switch
connector receptacle (Fig. 4) as shown in the Brake
Lamp Switch Tests table.
BRAKE LAMP SWITCH TESTS
PLUNGER POSITION CONTINUITY BETWEEN
Released (Extended) Pins1&2
Compressed (Retracted) Pins3&4,5&6
(3) If the switch fails any of the continuity tests,
replace the faulty brake lamp switch 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) Disconnect the instrument panel wire harness
connector for the brake lamp switch from the switch
connector receptacle (Fig. 5).
(3) Grasp the brake lamp switch housing firmly
and rotate the switch counterclockwise about 30
degrees to align the tabs on the locking collar with
the keyed mounting hole in the steering column sup-
port bracket.
(4) Pull the switch straight back from the mount-
ing hole to remove it from the steering column sup-
port bracket.
Fig. 4 Brake Lamp Switch Terminal Identification
1 - TERMINAL PINS
2 - PLUNGER TEST POSITIONS
Fig. 5 Brake Lamp Switch Remove/Install
1 - STEERING COLUMN SUPPORT
2 - WIRE HARNESS CONNECTOR
3 - LEVER
4 - BRAKE LAMP SWITCH
5 - BRAKE PEDAL ARM
KJLAMPS/LIGHTING - EXTERIOR 8L - 17
BRAKE LAMP SWITCH (Continued)

(5) Discard the removed brake lamp switch.
CAUTION: Always replace a removed brake lamp
switch with a new unit. This is a one time compo-
nent and is not intended for reinstallation.
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: Always replace a removed brake lamp
switch with a new unit. This is a one time compo-
nent and is not intended for reinstallation.
(1) While holding the brake pedal depressed, align
the tabs on the brake lamp switch locking collar with
the keyed mounting hole in the steering column sup-
port bracket (Fig. 5).
(2) Still holding the brake pedal depressed, insert
the tabs on the brake lamp switch housing through
the keyed mounting hole in the steering column sup-
port bracket until the switch is firmly seated against
the bracket.
(3) Still holding the brake pedal depressed, rotate
the switch clockwise about 30 degrees to lock the
tabs on the brake lamp switch locking collar to the
keyed mounting hole in the steering column support
bracket.
(4) Release the brake pedal.
CAUTION: Do not pull up on the brake pedal before
the switch plunger adjustment has been completed.
(5) Rotate the plunger adjustment release lever
clockwise until it locks into place parallel to the
brake lamp switch connector receptacle. This action
will set the switch plunger length to a final adjust-
ment position and cannot be undone. If not per-
formed properly the first time, a new brake lamp
switchmustbe installed.(6) Reconnect the instrument panel wire harness
connector for the brake lamp switch to the switch
connector receptacle.
(7) Reconnect the battery negative cable.
CENTER HIGH MOUNTED
STOP LAMP BULB
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Center High Mounted Stop Lamp
(CHMSL) unit from the roof panel. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
CENTER HIGH MOUNTED STOP LAMP UNIT -
REMOVAL).
(3) Firmly grasp the socket on the back of the
CHMSL unit housing.
(4) Rotate the socket on the back of the CHMSL
unit housing counterclockwise about 30 degrees (Fig.
6).
(5) Pull the socket and bulb straight out of the
back of CHMSL unit housing.
(6) Pull the bulb straight out of the CHMSL unit
socket.
Fig. 6 Center High Mounted Stop Lamp Bulb
Remove/Install
1 - CHMSL UNIT
2 - BULB
3 - SOCKET
4 - BODY WIRE HARNESS CONNECTOR
8L - 18 LAMPS/LIGHTING - EXTERIORKJ
BRAKE LAMP SWITCH (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.
(1) Align the base of the bulb with the receptacle
in the Center High Mounted Stop Lamp (CHMSL)
unit socket.
(2) Push the bulb straight into the CHMSL unit
socket until it is firmly seated.
(3) Align the socket and bulb with the socket open-
ing on the back of CHMSL unit housing.
(4) Push the socket and bulb straight into the
CHMSL unit housing until it is firmly seated (Fig. 6).
(5) Rotate the socket on the back of the CHMSL
unit housing clockwise about 30 degrees.
(6) Reinstall the CHMSL unit onto the roof panel.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/CENTER HIGH MOUNTED STOP
LAMP UNIT - INSTALLATION).
(7) Reconnect the battery negative cable.
CENTER HIGH MOUNTED
STOP LAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the two screws that secure the Center
High Mounted Stop Lamp (CHMSL) unit to the rear
of the roof panel (Fig. 7).
(3) Pull the CHMSL unit away from the roof panel
far enough to access and disconnect the wire harness
connector for the CHMSL unit from the lamp socket
pigtail wire.
(4) Remove the CHMSL unit from the roof panel.
INSTALLATION
(1) Position the Center High Mounted Stop Lamp
(CHMSL) unit to the roof panel.
(2) Reconnect the wire harness connector for the
CHMSL unit to the lamp socket pigtail wire (Fig. 7).
(3) Position the CHMSL unit into the roof panel
opening.
(4) Install and tighten the two screws that secure
the CHMSL unit to the rear of the roof panel.
Tighten the screws to 2 N´m (21 in. lbs.).
(5) Reconnect the battery negative cable.
COMBINATION FLASHER
DESCRIPTION
The combination flasher for this model is integral
to the hazard switch located in the center of the
instrument panel, just above the radio. The combina-
tion flasher is a smart relay that functions as both
the turn signal system and the hazard warning sys-
tem flasher. The combination flasher contains active
electronic Integrated Circuitry (IC) elements. This
flasher is designed to handle the current flow
requirements of the factory-installed lighting. If sup-
plemental lighting is added to the turn signal lamp
circuits, such as when towing a trailer with lights,
the combination flasher will automatically try to
compensate to keep the flash rate the same.
The combination flasher cannot be repaired or
adjusted and, if faulty or damaged, the hazard switch
unit must be replaced.
OPERATION
The combination flasher has the following inputs and
outputs: fused B(+), fused ignition switch output, right
turn signal sense, left turn signal sense, and one output
each for the right and left turn signal circuits. The com-
bination flasher also receives an internal input through
the closed contacts of the hazard switch and, on vehicles
equipped with the optional Vehicle Theft Security Sys-
tem (VTSS), the flasher receives an input from the Body
Control Module (BCM) in order to flash the turn signal
lamps as an optical alert feature of that system. Con-
Fig. 7 Center High Mounted Stop Lamp Remove/
Install
1 - ROOF PANEL
2 - BODY WIRE HARNESS CONNECTOR
3 - BULB SOCKET
4 - CHMSL
5 - SCREW (2)
6 - PLASTIC NUT (2)
KJLAMPS/LIGHTING - EXTERIOR 8L - 19
CENTER HIGH MOUNTED STOP LAMP BULB (Continued)

stant battery voltage is supplied to the flasher so that it
can perform the hazard warning function, and ignition
switched battery voltage is supplied for the turn signal
function. The Integrated Circuit (IC) within the combi-
nation 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 signals, and from the
hazard switch contacts or the BCM for the hazard
warning signals. A special design feature of the combi-
nation flasher allows it to9sense9that a turn signal cir-
cuit 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 flash-
es-per-minute or higher). Conventional flashers 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 features
a 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)
8L - 20 LAMPS/LIGHTING - EXTERIORKJ
COMBINATION FLASHER (Continued)

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) Remove the end cap from the driver side out-
board end of the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL END CAP - REMOVAL).
(3) Remove the Daytime Running Lamp (DRL)
relay by grasping it firmly and pulling it straight out
from the receptacle in the Junction Block (JB) (Fig.
9).
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 Daytime Running Lamp (DRL)
relay to the proper receptacle in the Junction Block
(JB) (Fig. 9).
(2) Align the DRL relay terminals with the termi-
nal cavities in the JB receptacle.
(3) Push firmly and evenly on the top of the DRL
relay until the terminals are fully seated in the ter-
minal cavities in the JB receptacle.
(4) Reinstall the end cap onto the driver side out-
board end of the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL END CAP - INSTALLATION).
(5) Reconnect the battery negative cable.
FRONT FOG LAMP BULB
REMOVAL
(1) Turn the front wheels full lock in the direction
of the fog lamp bulb that is to be changed.
(2) Disconnect and isolate the battery negative
cable.
(3) Reach into the front wheel opening to unsnap
and lift the cover over the access hole at the front of
the front wheelhouse splash shield (Fig. 10).
(4) Reach through the access hole and firmly grasp
the socket on the back of the front fog lamp unit
housing.
(5) Rotate the socket on the back of the front fog
lamp unit housing counterclockwise about 30
degrees.
CAUTION: Do not contaminate the bulb glass by
touching it with your fingers or by allowing it to
contact other oily surfaces. Shortened bulb life will
result.
Fig. 9 Junction Block - Outboard Side (RHD Shown
- Rotate 180É for LHD)
1 - JB/BCM CONNECTOR
2 - HIGH BEAM RELAY
3 - DRL RELAY
KJLAMPS/LIGHTING - EXTERIOR 8L - 21
DAYTIME RUNNING LAMP RELAY (Continued)

(6) Pull the socket and bulb straight out of the
front fog lamp unit housing and through the access
hole into the front wheel opening area.
(7) Pull the bulb straight out of the front fog lamp
unit socket.
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.
CAUTION: Do not contaminate the bulb glass by
touching it with your fingers or by allowing it to
contact other oily surfaces. Shortened bulb life will
result.
(1) Align the base of the bulb with the receptacle
in the front fog lamp unit socket.
(2) Push the bulb straight into the front fog lamp
unit socket until it is firmly seated.
(3) Position the socket and bulb through the access
hole in the front wheelhouse splash shield and align
it with the socket opening on the back of the front
fog lamp unit housing (Fig. 10).
(4) Push the socket and bulb straight into the
front fog lamp unit housing until it is firmly seated.
(5) Rotate the socket on the back of the front fog
lamp unit housing clockwise about 30 degrees.
(6) Lower and snap shut the access cover over the
hole at the front of the front wheelhouse splash
shield.
(7) Reconnect the battery negative cable.
FRONT FOG LAMP RELAY
DESCRIPTION
The front fog lamp relay is located in the Junction
Block (JB) on the driver side outboard end of the
instrument panel in the passenger compartment of
the vehicle. The front fog lamp relay is a conven-
tional International Standards Organization (ISO)
micro relay (Fig. 11). Relays conforming to the ISO
specifications have common physical dimensions, cur-
rent capacities, terminal patterns, and terminal func-
tions. The relay is contained within a small,
rectangular, molded plastic housing and is connected
to all of the required inputs and outputs by five inte-
gral male spade-type terminals that extend from the
bottom of the relay base.
The front fog lamp relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The front fog 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 front fog 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
Fig. 10 Front Fog Lamp Bulb Remove/Install
1 - FRONT WHEELHOUSE SPLASH SHIELD
2 - ACCESS HOLE
3 - SOCKET
4 - BULB
Fig. 11 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
8L - 22 LAMPS/LIGHTING - EXTERIORKJ
FRONT FOG LAMP BULB (Continued)

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 front fog 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 front fog lamp relay include:
²Common Feed Terminal- The common feed
terminal (30) receives battery current at all times
from a fuse in the JB through a fused B(+) circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the pre-
mium Body Control Module (BCM) through a front
fog lamp relay control circuit. The BCM controls
front fog 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 JB through a fused B(+) circuit.
²Normally Open Terminal- The normally open
terminal (87) is connected to the front fog lamps
through a front fog lamp relay output circuit and
provides battery current to the front fog lamps when-
ever the relay is energized.
²Normally Closed Terminal- The normally
closed terminal (87A) is not connected in this appli-
cation.
The front fog lamp relay can be diagnosed using
conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - FRONT FOG LAMP
RELAY
The front fog lamp relay (Fig. 12) is located in the
Junction Block (JB) under the driver side outboard
end of the instrument panel. Refer to the appropriate
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 connectors, splices
and grounds.
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) Remove the front fog lamp relay from the JB.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/FRONT FOG LAMP RELAY - REMOV-
AL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRBIIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
Fig. 12 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJLAMPS/LIGHTING - EXTERIOR 8L - 23
FRONT FOG LAMP RELAY (Continued)