2002 JEEP LIBERTY air condition

HAZARD SWITCH
DESCRIPTION
The hazard switch is integral to the hazard switch
module, which is secured near the center of instrument
panel just above the radio (Fig. 21). Only the hazard
switch button is visible through a dedicated, round, bev-
eled opening on the outer surface of the instrument
panel between the two center panel outlets of the heater
and air conditioning system. A red, stencil-like Interna-
tional Control and Display Symbol icon for ªHazard
Warningº identifies the hazard switch button. On the
opposite end of the black, molded plastic hazard switch
module housing from the switch button is an integral
connector receptacle and a stamped steel mounting
bracket with two latch feature tabs that extend down-
ward, while a short dowel-like alignment pin is integral
to each side of the housing just below the switch button.
The switch module is connected to the vehicle electrical
system through a dedicated take out and connector of
the instrument panel wire harness. Within the hazard
switch module housing is the hazard switch circuitry
and an electronic circuit board with the integral combi-
nation flasher circuitry. The electronic combination
flasher circuitry performs both the hazard flasher and
turn signal flasher functions.
The hazard switch module cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The hazard switch button is slightly recessed in the
instrument panel when the switch is in the Off position,
and latches at a position that is flush with the outer
surface of the instrument panel when in the On posi-tion. The hazard switch module produces an audible
clicking sound that emulates the sound of a conven-
tional flasher whenever the turn signals or the hazard
warning system are activated. The hazard switch mod-
ule receives battery current on a fused B(+) circuit from
a fuse in the Junction Block (JB) at all times for oper-
ation of the hazard warning, and on a fused ignition
switch output (run) circuit from another fuse in the JB
whenever the ignition switch is in the On position for
operation of the turn signals. The module 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. Inputs to and outputs from the hazard switch mod-
ule include:
²Panel Lamps Dimmer Input- A non-service-
able incandescent bulb soldered onto the hazard
switch module circuit board provides illumination of
the switch button when the exterior lighting is
turned On through an input received on the fused
panel lamps dimmer switch signal circuit. However,
this bulb flashes on and off at full intensity whenever
the hazard switch button is in the On position,
regardless of the status of the exterior lighting.
²Hazard Switch Input- The combination
flasher circuitry of the hazard switch module receives
an internal ground input from the hazard switch to
request hazard flasher operation.
²Multi-Function Switch Input- The combina-
tion flasher circuitry of the hazard switch module
receives separate ground inputs from the turn signal
switch circuitry of the multi-function switch on right
and left turn switch sense circuits to request right or
left turn signal flasher operation.
²Body Control Module Input- The Body Con-
trol Module (BCM) can request hazard flasher opera-
tion by providing a ground path to the combination
flasher circuitry of the hazard switch module through
a hazard lamp control circuit.
²Turn Signal Output- The combination flasher
circuitry within the hazard switch module responds
to the flasher request inputs by energizing and
de-energizing two miniature relays on the module
circuit board. These relays control the switch output
through the right and left turn signal circuits. One
relay controls the right lamps, while the other con-
trols the left.
Because of active electronic elements within the
hazard switch module, it cannot be tested with con-
ventional automotive electrical test equipment. If the
hazard switch module is believed to be faulty, replace
the switch with a known good unit to confirm system
operation.
Fig. 21 Hazard Switch
1 - HAZARD SWITCH BUTTON
2 - SCREW (1)
3 - MOUNTING BRACKET TABS
KJLAMPS/LIGHTING - EXTERIOR 8L - 29

LAMPS/LIGHTING - INTERIOR
TABLE OF CONTENTS
page page
LAMPS/LIGHTING - INTERIOR
DESCRIPTION.........................65
OPERATION...........................67
DIAGNOSIS AND TESTING - LAMPS/
LIGHTING - INTERIOR..................68
SPECIFICATIONS - LAMPS/LIGHTING -
INTERIOR...........................71
ASH RECEIVER LAMP BULB
REMOVAL.............................71
INSTALLATION.........................71
ASH RECEIVER LAMP UNIT
REMOVAL.............................72
INSTALLATION.........................72
CARGO LAMP BULB
REMOVAL.............................72
INSTALLATION.........................73
CARGO LAMP SWITCH
REMOVAL.............................73
INSTALLATION.........................74
CARGO LAMP UNIT
REMOVAL.............................74
INSTALLATION.........................74
COMPASS MINI-TRIP ILLUMINATION BULB
REMOVAL.............................74
INSTALLATION.........................75
COURTESY LAMP BULB
REMOVAL.............................75
INSTALLATION.........................76
COURTESY LAMP UNIT
REMOVAL.............................76INSTALLATION.........................77
DOOR AJAR SWITCH
DESCRIPTION.........................77
OPERATION...........................77
FLIP-UP GLASS AJAR SWITCH
DESCRIPTION.........................77
OPERATION...........................77
HEATER-A/C CONTROL ILLUMINATION BULB
REMOVAL.............................78
INSTALLATION.........................78
READING LAMP BULB
REMOVAL.............................79
INSTALLATION.........................79
READING LAMP SWITCH
REMOVAL.............................80
INSTALLATION.........................80
READING LAMP UNIT
REMOVAL.............................81
INSTALLATION.........................81
TAILGATE AJAR SWITCH
DESCRIPTION.........................82
OPERATION...........................82
TRANSMISSION RANGE INDICATOR
ILLUMINATION BULB
REMOVAL.............................82
INSTALLATION.........................83
VANITY LAMP BULB
REMOVAL.............................83
INSTALLATION.........................84
LAMPS/LIGHTING - INTERIOR
DESCRIPTION
The interior lighting system (Fig. 1) for this model
includes the following incandescent interior lamps:
²Ash Receiver Lamp- An available ash receiver
lamp is located above the ash receiver housing
behind the instrument panel center bezel, and is con-
trolled by the panel lamps dimmer circuit.
²Cargo Lamp- An available cargo lamp with an
integral lens-actuated courtesy disable switch is
located in the headliner near the rear roof header,
and is controlled by the courtesy lamp circuit.
²Courtesy Lamps- Available courtesy lamps are
located below both the right and left side of the
instrument panel, and are controlled by the courtesy
lamp circuit.²Compass Mini-Trip Control Illumination
Lamps- The optional Compass Mini-Trip Computer
(CMTC) has three replaceable control illumination
bulb/bulb holder units on its circuit board that are
controlled by the panel lamps dimmer circuit.
²Dome Lamp- A standard front dome lamp that
does not include an on-off switch is located in the
headliner near the windshield header, and is con-
trolled by the courtesy lamp circuit.
²Hazard Switch Illumination/Indicator
Lamp- The hazard switch control button has a non-
replaceable illumination/indicator bulb soldered onto
its circuit board that is controlled by both the hazard
switch circuitry and the panel lamps dimmer circuit.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/HAZARD SWITCH - DESCRIPTION).
²Heater-Air Conditioner Control Illumina-
tion Lamps- The heater-air conditioner control has
KJLAMPS/LIGHTING - INTERIOR 8L - 65

path to the switches using another internal driver
through the courtesy lamp load shed circuit. The
BCM provides a battery saver (load shedding) feature
for all courtesy lamps, which will automatically turn
these lamps off if they are left on for more than
about eight minutes with the ignition switch in the
Off position.
PANEL LAMPS DIMMER CIRCUIT The panel
lamps dimmer circuit includes the ElectroMechanical
Instrument Cluster (EMIC), heater-air conditioner
control, hazard switch and, depending upon the
selected vehicle options, ash receiver, and automatic
transmission range indicator illumination lamps. All
lamps in the panel lamps dimmer circuit are pro-
vided a path to ground at all times through a hard
wired ground circuit. These lamps illuminate based
upon inputs to the Body Control Module (BCM) from
the exterior lighting control knob and the interior
lighting control ring on the left (lighting) control
stalk of the multi-function switch. The control knob
on the left control stalk of the multi-function switch
selects the exterior lights, while the control ring
selects the panel lamps intensity (dimming) level.
When the exterior lighting is turned On, the BCM
energizes the park lamp relay and provides an elec-
tronic dimming level message to the ElectroMechani-
cal Instrument Cluster (EMIC), the radio, and the
Compass Mini-Trip Computer (CMTC) over the Pro-
grammable Communications Interface (PCI) data
bus. The energized park lamp relay provides a hard
wired battery current signal input to the EMIC on
the park lamp relay output circuit. The EMIC
responds to these inputs by supplying a 12-volt Pulse
Width Modulated (PWM) output to all of the incan-
descent lamps in the panel lamps dimmer circuit
over the fused panel lamps dimmer switch signal cir-
cuit. This shared PWM output synchronizes the
selected illumination intensity level of all of the
incandescent lamps in the panel lamps dimmer cir-
cuit.
The EMIC and the radio each use the electronic
dimming level message from the BCM to control and
synchronize the illumination intensity of their own
Vacuum Fluorescent Display (VFD), while the CMTC
uses the dimming level message to control the illumi-
nation intensity of both its VFD and its incandescent
lighting. In addition, when the control ring on the
left (lighting) control stalk of the multi-function
switch is moved to the Parade Mode detent position,
all of the VFDs are illuminated at their full intensity
levels for increased visibility when the vehicle is
driven during daylight hours with the exterior lights
turned On.DIAGNOSIS AND TESTING - LAMPS/LIGHTING
- INTERIOR
The hard wired circuits and components of the
interior lighting system may be diagnosed and tested
using conventional diagnostic tools and procedures.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the Body Control
Module (BCM), the ElectroMechanical Instrument
Cluster (EMIC), or the Programmable Communica-
tions Interface (PCI) data bus network. The most
reliable, efficient, and accurate means to diagnose
the BCM, the EMIC, and the PCI data bus network
inputs and outputs related to the various interior
lighting systems requires the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
When diagnosing the interior lighting circuits,
remember that high generator output can burn out
bulbs rapidly and repeatedly; and, that dim or flick-
ering bulbs can be caused by low generator output or
poor battery condition. If one of these symptoms is a
problem on the vehicle being diagnosed, be certain to
diagnose and repair the battery and charging system
as required. Also keep in mind that a good ground is
necessary for proper lighting operation. If a lighting
problem is being diagnosed that involves multiple
symptoms, systems, or components the problem can
often be traced to a loose, corroded, or open ground.
For complete circuit diagrams, refer to the appropri-
ate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
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.
8L - 68 LAMPS/LIGHTING - INTERIORKJ
LAMPS/LIGHTING - INTERIOR (Continued)

COURTESY LAMP CIRCUIT
CONDITION POSSIBLE CAUSES CORRECTION
A SINGLE LAMP IN THE
COURTESY LAMP
CIRCUIT DOES NOT
ILLUMINATE1. Faulty or missing bulb. 1. Test and replace the courtesy lamp bulb
as required.
2. Faulty lamp switch. 2. Test and replace a faulty map/reading
lamp switch, cargo lamp switch, or sunvisor
(vanity lamp switch) as required.
3. Faulty ground circuit. 3. Test and repair the open courtesy lamp
driver circuit as required.
4. Faulty ground circuit
(independently switched lamps only).4. Test and repair the open courtesy lamp
load shed circuit as required.
5. Faulty feed circuit. 5. Test and repair the open fused B(+)
circuit as required.
ALL LAMPS IN THE
COURTESY LAMP
CIRCUIT DO NOT
ILLUMINATE1. Faulty or missing fuse. 1. Test and replace the fused B(+) fuse
(IOD) in the Junction Block (JB) as
required.
2. Faulty ground circuit. 2. Test and repair the open courtesy lamp
driver circuit as required.
3. Faulty feed circuit. 3. Test and repair the open fused B(+)
circuit as required.
4. Faulty cargo lamp (courtesy
defeat) switch.4. Test and replace the cargo lamp switch
as required.
5. Faulty rear courtesy lamp control
circuit.5. Test and repair the shorted courtesy
lamp control circuit as required.
6. Faulty multi-function switch. 6. Test and replace the multi-function switch
as required.
7. Faulty Body Control Module
(BCM), BCM input, or BCM output.7. Use a DRBIIITscan tool to test the BCM,
its inputs, and its outputs. Refer to the
appropriate diagnostic information.
A SINGLE LAMP IN THE
COURTESY LAMP
CIRCUIT DOES NOT
EXTINGUISH1. Faulty lamp switch. 1. Test and replace a faulty map/reading
lamp switch, cargo lamp switch, or sunvisor
(vanity lamp switch) as required.
2. Faulty ground circuit. 2. Test and repair the shorted courtesy
lamp driver circuit as required.
ALL LAMPS IN THE
COURTESY LAMP
CIRCUIT DO NOT
EXTINGUISH1. Faulty ajar switch. 1. Test and replace a faulty door, tailgate,
or liftglass ajar switch as required.
2. Faulty ajar switch sense circuit. 2. Test and repair the shorted ajar switch
sense circuit as required.
3. Faulty ground circuit. 3. Test and repair the shorted courtesy
lamp driver circuit as required.
4. Faulty Body Control Module
(BCM), BCM input, or BCM output.4. Use a DRBIIITscan tool to test the BCM,
its inputs, and its outputs. Refer to the
appropriate diagnostic information.
KJLAMPS/LIGHTING - INTERIOR 8L - 69
LAMPS/LIGHTING - INTERIOR (Continued)

PANEL LAMPS DIMMER CIRCUIT
CONDITION POSSIBLE CAUSES CORRECTION
A SINGLE LAMP DOES
NOT ILLUMINATE1. Faulty or missing bulb. 1. Test and replace lamp bulb as required.
2. Faulty ground circuit. 2. Test and repair lamp ground circuit as
required.
3. Faulty feed circuit. 3. Test and repair open fused panel lamps
dimmer switch signal circuit as required.
A SINGLE LAMP DOES
NOT EXTINGUISH1. Faulty feed circuit. 1. Test and repair shorted fused panel
lamps dimmer switch signal circuit as
required.
ALL LAMPS DO NOT
ILLUMINATE1. Faulty fused park lamp relay
output circuit.1. Test and repair open fused park lamp
relay output circuit as required.
2. Faulty or missing park
lamp relay.2. Test and replace park lamp relay as
required.
3. Faulty fused panel lamps dimmer
switch signal circuit.3. Test and repair open fused panel lamps
dimmer switch signal circuit as required.
4. Faulty Body Control Module
(BCM), BCM input, or BCM output.4. Use a DRBIIITscan tool to test the BCM,
its inputs, and its outputs. Refer to the
appropriate diagnostic information.
5. Faulty ElectroMechanical
Instrument Cluster (EMIC), EMIC
input, or EMIC output.5. Use a DRBIIITscan tool to test the
EMIC, its inputs, and its outputs. Refer to
the appropriate diagnostic information.
6. Faulty multi-function switch. 6. Test and replace the multi-function switch
as required.
ALL LAMPS EXCEPT
CLUSTER ILLUMINATION
DO NOT EXTINGUISH1. Faulty feed circuit. 1. Test and repair shorted fused panel
lamps dimmer switch signal circuit as
required.
8L - 70 LAMPS/LIGHTING - INTERIORKJ
LAMPS/LIGHTING - INTERIOR (Continued)

exterior lighting systems requires the use of a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
When diagnosing the exterior lighting circuits,
remember that high generator output can burn out
bulbs rapidly and repeatedly; and, that dim or flick-
ering bulbs can be caused by low generator output or
poor battery condition. If one of these symptoms is a
problem on the vehicle being diagnosed, be certain to
diagnose and repair the battery and charging system
as required. Also keep in mind that a good ground is
necessary for proper lighting operation. If a lighting
problem is being diagnosed that involves multiple
symptoms, systems, or components the problem can
often be traced to a loose, corroded, or open ground.
For complete circuit diagrams, refer to the appropri-
ate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information andlocation views for the various wire harness connec-
tors, 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.
BACKUP LAMPS
CONDITION POSSIBLE CAUSES CORRECTION
BACKUP LAMP DOES
NOT ILLUMINATE1. Faulty or missing fuse. 1. Test and replace backup lamp fuse as
required.
2. Faulty or missing bulb. 2. Test and replace backup lamp bulb as
required.
3. Faulty switch. 3. Test and replace backup lamp switch
(manual transmission) or transmission
range sensor (automatic transmission) as
required.
4. Faulty ground circuit. 4. Test and repair backup lamp ground
circuit as required.
5. Faulty feed circuit. 5. Test and repair open back-up lamp feed
circuit as required.
BACKUP LAMP DOES
NOT EXTINGUISH1. Faulty switch. 1. Test and replace backup lamp switch
(manual transmission) or transmission
range sensor (automatic transmission) as
required.
2. Faulty feed circuit. 2. Test and repair shorted back-up lamp
feed circuit as required.
8Ls - 8 LAMPSKJ
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)

FRONT FOG LAMPS
CONDITION POSSIBLE CAUSES CORRECTION
FRONT FOG LAMP DOES
NOT ILLUMINATE1. Faulty or missing fuse. 1. Test and replace front fog lamp fuse as
required.
2. Faulty or missing bulb. 2. Test and replace front fog lamp bulb as
required.
3. Faulty or missing relay. 3. Test and replace front fog lamp relay as
required.
4. Faulty switch. 4. Test and replace multi-function switch as
required.
5. Faulty ground circuit. 5. Test and repair front fog lamp ground
circuit as required.
6. Faulty feed circuit. 6. Test and repair open front fog lamp 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.
FRONT FOG LAMP DOES
NOT EXTINGUISH1. Faulty relay. 1. Test and replace front fog lamp relay as
required.
2. Faulty switch. 2. Test and replace multi-function switch as
required.
3. Faulty feed circuit. 3. Test and repair shorted front fog lamp
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.
HAZARD WARNING LAMPS
Before performing the following tests, confirm
whether the left and right turn signals operate satis-
factorily. If the turn signals are inoperative or oper-ate improperly, diagnose and repair that problem
before attempting to repair the Hazard Warning
Lamps.
CONDITION POSSIBLE CAUSES CORRECTION
HAZARD WARNING
LAMPS DO NOT FLASH1. Faulty or missing fuse. 1. Test and replace hazard warning fuse as
required.
2. Faulty ground circuit. 2. Test and repair hazard switch ground
circuit as required.
3. Faulty feed circuit. 3. Test and repair open hazard switch fused
B(+) circuit as required.
4. Faulty switch/flasher. 4. Replace hazard switch/combination
flasher with a known good unit and check
operation. Replace hazard switch/
combination flasher unit if required.
8Ls - 10 LAMPSKJ
LAMPS/LIGHTING - EXTERIOR (Continued)