2001 DODGE RAM lock

OPERATION
The heated seat module receives fused battery cur-
rent through the energized heated seat relay in the
Junction Block (JB) only when the engine is running.
The heated seat switches receive battery current
through a fused ignition switch output (run) circuit
only when the ignition switch is in the On position.
The heated seat module shares a common ground cir-
cuit with each of the heated seat elements. The
heated seat elements will only operate when the sur-
face temperature of the seat cushion cover at the
heated seat sensors is below the designed tempera-
ture set points of the system.
The heated seat module will automatically turn off
the heated seat elements if it detects a short in the
heated seat element circuit or a heated seat sensor
value that is out of range. The heated seat system
will also be turned off automatically whenever the
ignition switch is turned to any position except On or
if the engine quits running. If the ignition switch is
turned to the Off position or if the engine quits run-
ning while a heated seat is turned ON, the heated
seat will remain Off after the engine is restarted
until a heated seat switch is depressed again.
The heated seat module monitors inputs from the
heated seat sensors and the heated seat switches. In
response to these inputs the heated seat module uses
its internal programming to control outputs to the
heated seat elements in both front seats and to con-
trol the heated seat LED indicator lamps located in
both of the heated seat switches. The heated seat
module is also programmed to provide a self-diagnos-
tic capability. When the module detects certain fail-
ures within the heated seat system, it will provide a
visual indication of the failure by flashing the indica-
tor lamps in the heated seat switches.
DIAGNOSIS & TESTING - HEATED SEAT
SYSTEM
SELF-DIAGNOSIS
The heated seat system is capable of performing
some self-diagnostics. The following table depicts the
various failure modes which will be reported to the
vehicle operator or technician by flashing the individ-
ual heated seat switch Light Emitting Diode (LED)
indicator lamps. See the Heated Seat System Self-Di-
agnosis table for the diagnostic routines. The driver
side heated seat switch indicator lamps will flash if a
failure occurs in the driver side heated seat, and the
passenger side heated seat switch indicator lamps
will flash for a passenger side heated seat failure. If
a monitored heated seat system failure occurs, the
switch indicator lamps will flash at a pulse rate of
about one-half second on, followed by about one-half
second off for a duration of about one minute afterthe switch for the faulty heated seat is depressed in
either the Low or High direction. This process will
repeat every time the faulty heated seat switch is
actuated until the problem has been corrected.
Heated Seat System Self-Diagnosis
Monitored FailureSwitch High
Indicator LampSwitch Low
Indicator Lamp
Heated Seat
Element ShortedFlashing Flashing
Heated Seat
Element OpenFlashing Off
Heated Seat
Sensor Value Out
of RangeOff Flashing
TESTING
Refer toPower Seatin the index of this service
manual for the location of complete heated seat sys-
tem wiring diagrams. Before testing the individual
components in the heated seat system, perform the
following preliminary checks:
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
²If the heated seat switch back lighting and the
cluster illumination lamps do not illuminate with the
headlamps or park lamps turned On, refer toInstru-
ment Clusterin the index of this service manual for
the location of the proper cluster illumination lamps
diagnosis and testing procedures. If the heated seat
switch back lighting does not illuminate, but the
cluster illumination lamps do illuminate with the
headlamps or park lamps turned On, refer to
Heated Seat Switchin this section for the location
of the proper heated seat switch diagnosis and test-
ing procedure.
²If a single indicator lamp for one heated seat
switch does not operate and the heated seat elements
do heat, refer toHeated Seat Switchin this section
for the location of the proper heated seat switch diag-
nosis and testing procedure.
8G - 6 HEATED SEAT SYSTEMBR/BE
HEATED SEAT SYSTEM (Continued)

The indicator lamps in the heated seat switches
receive battery current through a fused ignition
switch output (run) circuit when the ignition switch
is in the On position. The ground side of each indi-
cator lamp is controlled by a separate (high or low/
driver or passenger) indicator lamp driver circuit by
the heated seat module. The heated seat module con-
trol of the switch indicator lamps also allows the
module to provide diagnostic feedback to the vehicle
operator to indicate monitored heated seat system
faults by flashing the indicator lamps on and off. One
side of the incandescent back lighting bulb in each
heated seat switch is connected to ground at all
times. The other side of the incandescent bulb is con-
nected to the fused panel lamps dimmer switch sig-
nal circuit. These bulbs are energized when the park
lamps or headlamps are turned on, and their illumi-
nation intensity is controlled by the panel lamps dim-
mer switch.
DIAGNOSIS & TESTING - HEATED SEAT
SWITCH
Refer toWiring Diagramsfor the location of com-
plete heated seat system wiring diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) If the problem being diagnosed involves inoper-
ative heated seat switch back lighting and the cluster
illumination lamps operate, go to Step 2. If the prob-
lem being diagnosed involves inoperative heated seat
switch back lighting and the cluster illumination
lamps are also inoperative, refer toInstrument
Clusterin the index of this service manual for the
proper cluster illumination lamps diagnosis and test-
ing procedures. If the problem being diagnosed
involves inoperative heated seat switch indicator
lamps and the heated seat elements do not heat,
refer to Step 4. If the problem being diagnosed
involves inoperative heated seat switch indicator
lamps and the heated seat elements do heat, go to
Step 8. If the problem being diagnosed involves a
heated seat switch indicator lamp that remains illu-minated after the heated seat has been turned Off,
refer toHeated Seat Modulein Electronic Control
Modules for the location of the proper heated seat
module diagnosis and testing procedures. Also refer
to the Body Diagnostic Manual for additional diagno-
sis and testing procedures.
(2) Disconnect and isolate the battery negative
cable. Remove the heated seat switch and bezel unit
from the instrument panel. Disconnect the instru-
ment panel wire harness connector from the connec-
tor receptacle on the back of the heated seat switch
to be tested. Check for continuity between the ground
circuit cavity of the instrument panel wire harness
connector for the heated seat switch and a good
ground. There should be continuity. If OK, go to Step
3. If not OK, repair the open ground circuit to ground
as required.
(3) Reconnect the battery negative cable. Turn the
park lamps on with the headlamp switch. Rotate the
panel lamps dimmer thumbwheel on the headlamp
switch upward to just before the interior lamps
detent. Check for battery voltage at the fused panel
lamps dimmer switch signal circuit cavity of the
instrument panel wire harness connector for the
heated seat switch. If OK, replace the faulty heated
seat switch. If not OK, repair the open fused panel
lamps dimmer switch signal circuit to the fuse in the
Junction Block (JB) as required.
(4) Check the fused ignition switch output (run)
fuse in the Junction Block (JB). If OK, go to Step 5.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(5) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run) fuse in the JB. If OK, go to Step 6. If
not OK, repair the open fused ignition switch output
(run) circuit to the ignition switch as required.
(6) Disconnect and isolate the battery negative
cable. Remove the heated seat switch and bezel unit
from the instrument panel. Disconnect the instru-
ment panel wire harness connector from the connec-
tor receptacle on the back of the heated seat switch
to be tested. Reconnect the battery negative cable.
Turn the ignition switch to the On position. Check
for battery voltage at the fused ignition switch out-
put (run) circuit cavity of the instrument panel wire
harness connector for the heated seat switch. If OK,
go to Step 7. If not OK, repair the open fused ignition
switch output (run) circuit to the JB fuse as required.
(7) Check the continuity and resistance values of
the heated seat switch in the Neutral, Low and High
positions as shown in the Heated Seat Switch Conti-
nuity chart (Fig. 3). If OK, refer toHeated Seat
Modulein Electronic Control Modules for the loca-
tion of the proper heated seat module diagnosis and
testing procedures. Also refer to the Body Diagnostic
8G - 8 HEATED SEAT SYSTEMBR/BE
DRIVER SEAT HEATER SWITCH (Continued)

DIAGNOSIS & TESTING - HEATED SEAT
ELEMENT AND SENSOR
The heated seat module will self-diagnose shorted
or open heated seat element circuits and the sensor
circuits. Refer toHeated Seat Systemin this sec-
tion for the location of the proper heated seat system
diagnosis and testing procedures. To manually check
the heated seat element and sensor circuits, proceed
as follows. The wire harness connectors for the seat
cushion heated seat element and sensor and for the
seat back heated seat element are located under the
seat, near the rear edge of the seat cushion frame.
Refer toWiring Diagramsfor the location of com-
plete heated seat system wiring diagrams.
HEATED SEAT ELEMENT
(1) Disconnect and isolate the battery negative
cable. Disconnect the 4-way heated seat wire harness
connector. Check for continuity between the two
heated seat element circuit cavities in the seat cush-
ion trim cover half of the 4-way heated seat wire har-
ness connector. There should be continuity. If OK, go
to Step 2. If not OK, go to Step 3.
(2) Check for continuity between one of the heated
seat element circuit cavities in the seat cushion trim
cover half of the 4-way heated seat wire harness con-
nector and the seat cushion frame. There should be
no continuity. If OK, go to Step 5. If not OK, go to
Step 4.
(3) Disconnect the 2-way heated seat wire harness
connector between the seat cushion trim cover and
the seat back trim cover. Check for continuity
between the heated seat element circuit cavity and
the ground circuit cavity in the seat back trim cover
half of the 2-way heated seat wire harness connector.
There should be continuity. If OK, go to Step 5. If not
OK, replace the faulty seat back trim cover unit.
(4) Check for continuity between the heated seat
element circuit cavity in the seat back trim cover half
of the 2-way heated seat wire harness connector and
the seat back frame. There should be no continuity. If
OK, go to Step 5. If not OK, replace the faulty seat
back trim cover unit.
(5) Test the seat wire harness between the heated
seat module connector and the 4-way heated seat
wire harness connectors for shorted or open circuits.
If OK, replace the faulty seat cushion trim cover
unit. If not OK, repair the shorted or open seat wire
harness as required.
HEATED SEAT SENSOR
(1) Disconnect and isolate the battery negative
cable. Disconnect the 4-way heated seat wire harness
connector. Using an ohmmeter, check the resistance
between the heated seat sensor input circuit cavity
and the heated seat sensor feed circuit cavity in theseat cushion cover half of the 4-way heated seat wire
harness connector. The heated seat sensor resistance
should be between 1 kilohm and 200 kilohms. If OK,
go to Step 2. If not OK, replace the faulty seat cush-
ion trim cover unit.
(2) Test the seat wire harness between the heated
seat module connector and the 4-way heated seat
wire harness connector for shorted or open circuits. If
OK, refer toHeated Seat Modulein Electronic
Control Modules for the location of the proper heated
seat module diagnosis and testing procedures. Also
refer to the Body Diagnostic Manual for additional
diagnosis and testing procedures. If not OK, repair
the shorted or open heated seat wire harness as
required.
HEATED SEAT RELAY
DESCRIPTION
The heated seat relay is an electromechanical
device that switches battery current to the heated
seat module when the relay control coil is energized.
The heated seat relay is located in the Junction
Block (JB), on the left end of the instrument panel in
the passenger compartment (Fig. 6). The heated seat
relay is a International Standards Organization
(ISO) micro-relay. Relays conforming to the ISO spec-
Fig. 6 Heated Seat Relay
1 - JUNCTION BLOCK
2 - HEATED SEAT RELAY
3 - INSTRUMENT PANEL
4 - COMBINATION FLASHER
BR/BEHEATED SEAT SYSTEM 8G - 11
HEATED SEAT ELEMENT (Continued)

ifications have common physical dimensions, current
capacities, terminal patterns, and terminal functions.
The ISO micro-relay terminal functions are the same
as a conventional ISO relay. However, the ISO micro-
relay terminal pattern (or footprint) is different, the
current capacity is lower, and the physical dimen-
sions are smaller than those of the conventional ISO
relay.
The heated seat relay cannot be repaired or
adjusted and, if faulty or damaged, it must be
replaced.
OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor or diode, and three (two fixed and one mov-
able) electrical contacts. The movable (common feed)
relay contact is held against one of the fixed contacts
(normally closed) by spring pressure. When the elec-
tromagnetic coil is energized, it draws the movable
contact away from the normally closed fixed contact,
and holds it against the other (normally open) fixed
contact. When the electromagnetic coil is de-ener-
gized, spring pressure returns the movable contact to
the normally closed position. The resistor or diode is
connected in parallel with the electromagnetic coil in
the relay, and helps to dissipate voltage spikes that
are produced when the coil is de-energized.
The heated seat relay is controlled by the premium
version of the Central Timer Module (CTM), which
controls the ground feed to the coil ground terminal
of the relay to energize and de-energize the electro-
magnetic coil of the relay. The CTM monitors engine
operation through messages it receives from the Pow-
ertrain Control Module (PCM) over the Chrysler Col-
lision Detection (CCD) data bus network. The CTM is
programmed to energize the relay only when the
engine is running, and to de-energize the relay when
the engine is not running. Refer toCentral Timer
Modulein the index of this service manual for the
location of more information on the premium CTM.
DIAGNOSIS & TESTING - HEATED SEAT RELAY
The heated seat relay (Fig. 7) is located in the
Junction Block (JB) on the left end of the instrument
panel in the passenger compartment of the vehicle.
Refer toWiring Diagramsfor the location of com-
plete heated seat system wiring diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
RELAY TEST
(1) Remove the heated seat relay from the JB.
Refer toHeated Seat Relayin this section for the
location of the proper heated seat relay removal pro-
cedures.
(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   5 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, perform the Relay Circuit Test that
follows. If not OK, replace the faulty relay.
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fused B(+) fuse in the Power Distribu-
tion Center (PDC) as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
Fig. 7 Heated Seat Relay
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
8G - 12 HEATED SEAT SYSTEMBR/BE
HEATED SEAT RELAY (Continued)

(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the heated seat module. There should be continu-
ity between the cavity for relay terminal 87 and the
B(+) to heated seat module circuit cavity of the
heated seat module wire harness connector at all
times. If OK, go to Step 4. If not OK, repair the open
B(+) to heated seat module circuit to the heated seat
module as required.
(4) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is connected to bat-
tery voltage and should be hot at all times. Check for
battery voltage at the cavity for relay terminal 86. If
OK, go to Step 5. If not OK, repair the open circuit to
the fused B(+) fuse in the PDC as required.
(5) The coil ground terminal (85) is connected to
the electromagnet in the relay. It is grounded by the
premium version of the Central Timer Module (CTM)
in response to an engine speed message received over
the Chrysler Collision Detection (CCD) data bus from
the Powertrain Control Module (PCM) when the
engine is running. Check for continuity between the
cavity for relay terminal 85 and the heated seat relay
control circuit cavity of the CTM wire harness con-
nector. There should be continuity at all times. If OK,
use a DRBIIItscan tool and the proper diagnostic
procedures manual to test the operation of the CTM
and CCD data bus. If not OK, repair the open heated
seat relay control circuit as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse access panel by inserting a
finger in the finger recess molded into the panel and
then pulling the panel sharply away from the left
outboard end of the instrument panel.
(3) The heated seat relay is located on the forward
side of the Junction Block (JB), just above the com-
bination flasher (Fig. 8).
(4) Grasp the heated seat relay firmly and pull it
straight out from the JB.
INSTALLATION
(1) Position the heated seat relay in the proper
receptacle in the JB.
(2) Align the heated seat relay terminals with the
terminal cavities in the JB receptacle.
(3) Push in firmly on the heated seat relay until
the terminals are fully seated in the terminal cavities
in the JB receptacle.
(4) Insert the tabs on the forward edge of the fuse
access panel in the notches on the forward edge of
the instrument panel fuse access panel opening.(5) Press the rear edge of the fuse access panel in
toward the instrument panel until the panel snaps
back into place.
(6) Reconnect the battery negative cable.
PASSENGER SEAT HEATER
SWITCH
DESCRIPTION
The heated seat switches used on vehicles with
this option are both mounted in a heated seat switch
bezel (Fig. 9), which replaces the standard equipment
cubby bin located in the lower right corner of the
instrument cluster bezel next to the radio receiver.
The two switches are snapped into the mounting
holes of the heated seat switch bezel, and the heated
seat switch bezel is secured with three screws to the
instrument panel. The mounts for the heated seat
switch bezel are concealed behind the instrument
cluster bezel. The two heated seat switches are iden-
tical in appearance and construction, except for the
location of a keyway in the single connector recepta-
cle on the back of each switch. The instrument panel
wire harness connectors for the heated seat switches
are keyed to match the connector receptacles on the
switches so that the two heated seat switches can
only be connected to the proper heated seat.
Fig. 8 Heated Seat
1 - JUNCTION BLOCK
2 - HEATED SEAT RELAY
3 - INSTRUMENT PANEL
4 - COMBINATION FLASHER
BR/BEHEATED SEAT SYSTEM 8G - 13
HEATED SEAT RELAY (Continued)

Clusterin the index of this service manual for the
proper cluster illumination lamps diagnosis and test-
ing procedures. If the problem being diagnosed
involves inoperative heated seat switch indicator
lamps and the heated seat elements do not heat,
refer to Step 4. If the problem being diagnosed
involves inoperative heated seat switch indicator
lamps and the heated seat elements do heat, go to
Step 8. If the problem being diagnosed involves a
heated seat switch indicator lamp that remains illu-
minated after the heated seat has been turned Off,
refer toHeated Seat Modulein Electronic Control
Modules for the location of the proper heated seat
module diagnosis and testing procedures. Also refer
to the Body Diagnostic Manual for additional diagno-
sis and testing procedures.
(2) Disconnect and isolate the battery negative
cable. Remove the heated seat switch and bezel unit
from the instrument panel. Disconnect the instru-
ment panel wire harness connector from the connec-
tor receptacle on the back of the heated seat switch
to be tested. Check for continuity between the ground
circuit cavity of the instrument panel wire harness
connector for the heated seat switch and a good
ground. There should be continuity. If OK, go to Step
3. If not OK, repair the open ground circuit to ground
as required.
(3) Reconnect the battery negative cable. Turn the
park lamps on with the headlamp switch. Rotate the
panel lamps dimmer thumbwheel on the headlamp
switch upward to just before the interior lamps
detent. Check for battery voltage at the fused panel
lamps dimmer switch signal circuit cavity of the
instrument panel wire harness connector for the
heated seat switch. If OK, replace the faulty heated
seat switch. If not OK, repair the open fused panel
lamps dimmer switch signal circuit to the fuse in the
Junction Block (JB) as required.
(4) Check the fused ignition switch output (run)
fuse in the Junction Block (JB). If OK, go to Step 5.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(5) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run) fuse in the JB. If OK, go to Step 6. If
not OK, repair the open fused ignition switch output
(run) circuit to the ignition switch as required.
(6) Disconnect and isolate the battery negative
cable. Remove the heated seat switch and bezel unit
from the instrument panel. Disconnect the instru-
ment panel wire harness connector from the connec-
tor receptacle on the back of the heated seat switch
to be tested. Reconnect the battery negative cable.
Turn the ignition switch to the On position. Check
for battery voltage at the fused ignition switch out-
put (run) circuit cavity of the instrument panel wireharness connector for the heated seat switch. If OK,
go to Step 7. If not OK, repair the open fused ignition
switch output (run) circuit to the JB fuse as required.
(7) Check the continuity and resistance values of
the heated seat switch in the Neutral, Low and High
positions as shown in the Heated Seat Switch Conti-
nuity chart (Fig. 10). If OK, refer toHeated Seat
Modulein Electronic Control Modules for the loca-
tion of the proper heated seat module diagnosis and
testing procedures. Also refer to the Body Diagnostic
Manual for additional diagnosis and testing proce-
dures. If not OK, replace the faulty heated seat
switch.
Heated Seat Switch Continuity
Switch PositionContinuity
BetweenResistance
Neutral 4 & 6 2.2 Kilohms
Low 4 & 6 510 Ohms
High 4 & 6 33 Ohms
(8) Replace the inoperative heated seat switch
with a known good unit and test the operation of the
switch indicator lamps. If OK, discard the faulty
heated seat switch. If not OK, refer toHeated Seat
Modulein Electronic Control Modules for the loca-
tion of the proper heated seat module diagnosis and
testing procedures. Also refer to the Body Diagnostic
Manual for additional diagnosis and testing proce-
dures.
REMOVAL
Both heated seat switches and the heated seat
switch bezel are available individually for service
replacement.
(1) Disconnect and isolate the battery negative
cable.
Fig. 10 Heated Seat Switch
BR/BEHEATED SEAT SYSTEM 8G - 15
PASSENGER SEAT HEATER SWITCH (Continued)

HORN
TABLE OF CONTENTS
page page
HORN
DESCRIPTION............................1
OPERATION.............................1
HORN
DESCRIPTION............................2
OPERATION.............................2
DIAGNOSIS AND TESTING..................2
HORN................................2
REMOVAL...............................2
INSTALLATION............................3
HORN RELAY
DESCRIPTION............................3OPERATION.............................3
DIAGNOSIS AND TESTING..................3
HORN RELAY..........................3
REMOVAL...............................4
INSTALLATION............................4
HORN SWITCH
DESCRIPTION............................4
OPERATION.............................5
DIAGNOSIS AND TESTING..................5
HORN SWITCH.........................5
REMOVAL...............................5
HORN
DESCRIPTION
An electric horn system is standard factory-in-
stalled equipment on this model. Two horn systems
are offered on this model. The standard equipment
horn system features a single low-note electromag-
netic horn unit, while the optional dual horn system
features one low-note horn unit and one high-note
horn unit. Both horn systems use a non-switched
source of battery current so that the system will
remain functional, regardless of the ignition switch
position. The horn system includes the following com-
ponents:
²Clockspring
²High-line or premium Central Timer Module
(CTM)
²Horn(s)
²Horn relay
²Horn switch
(Refer to 8 - ELECTRICAL/RESTRAINTS/CLOCK-
SPRING - DESCRIPTION) for more information on
this component. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/BODY CONTROL/
CENTRAL TIMER MODUL - DESCRIPTION) for
more information on this component. Refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds. Following are general
descriptions of the remaining major components in
the horn system.
OPERATION
Each horn system is activated by a horn switch
concealed beneath the driver side airbag module trim
cover in the center of the steering wheel. Depressing
the center of the driver side airbag module trim cover
closes the horn switch. Closing the horn switch acti-
vates the horn relay. The activated horn relay then
switches the battery current needed to energize the
horn(s).
Refer to the owner's manual in the vehicle glove
box for more information on the features, use and
operation of the horn system.
CENTRAL TIMER MODULE
The high-line or premium Central Timer Module
(CTM) can also operate the horn system. A high-line
CTM is used on high-line versions of this vehicle. A
premium CTM is used on vehicles equipped with the
optional heated seats. The CTM combines the func-
tions of a chime/buzzer module, an intermittent wipe
module, an illuminated entry module, a remote key-
less entry module, and a vehicle theft security sys-
tem module in a single unit.
The high-line or premium CTM also controls and
integrates many of the additional electronic functions
and features included on models with this option.
The horn relay is one of the hard wired outputs of
the CTM. The high-line or premium CTM is pro-
grammed to energize or de-energize the horn relay in
response to certain inputs from the Vehicle Theft
Security System (VTSS) and/or the Remote Keyless
Entry (RKE) system.
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/BODY CONTROL/CENTRAL
TIMER MODUL - DESCRIPTION) for more informa-
BR/BEHORN 8H - 1

tion on the high-line or premium CTM. (Refer to 8 -
ELECTRICAL/VEHICLE THEFT SECURITY - GEN-
ERAL INFORMATION) for more information on the
VTSS. (Refer to 8 - ELECTRICAL/POWER LOCKS -
GENERAL INFORMATION) for more information on
the RKE system.
HORN
DESCRIPTION
The standard single, low-note, electromagnetic dia-
phragm-type horn is secured with a bracket to the
right front fender wheel house extension in the
engine compartment. The high-note horn for the
optional dual-note horn system is connected in paral-
lel with and secured with a bracket just forward of
the low-note horn. Each horn is grounded through its
wire harness connector and circuit to a ground splice
joint connector, and receives battery feed through the
closed contacts of the horn relay.
The horns cannot be repaired or adjusted and, if
faulty or damaged, they must be individually replaced.
OPERATION
Within the two halves of the molded plastic horn
housing are a flexible diaphragm, a plunger, an elec-
tromagnetic coil and a set of contact points. The dia-
phragm is secured in suspension around its
perimeter by the mating surfaces of the horn hous-
ing. The plunger is secured to the center of the dia-
phragm and extends into the center of the
electromagnet. The contact points control the current
flow through the electromagnet.
When the horn is energized, electrical current
flows through the closed contact points to the electro-
magnet. The resulting electromagnetic field draws
the plunger and diaphragm toward it until that
movement mechanically opens the contact points.
When the contact points open, the electromagnetic
field collapses allowing the plunger and diaphragm to
return to their relaxed positions and closing the con-
tact points again. This cycle continues repeating at a
very rapid rate producing the vibration and move-
ment of air that creates the sound that is directed
through the horn outlet.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HORN
For complete circuit diagrams, refer to the appro-
priate 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.
(1) Disconnect the wire harness connector(s) from
the horn connector receptacle(s). Measure the resis-
tance between the ground circuit cavity of the horn(s)
wire harness connector(s) and a good ground. There
should be no measurable resistance. If OK, go to Step
2. If not OK, repair the open ground circuit to ground
as required.
(2) Check for battery voltage at the horn relay out-
put circuit cavity of the horn(s) wire harness connec-
tor(s). There should be zero volts. If OK, go to Step 3.
If not OK, repair the shorted horn relay output cir-
cuit or replace the faulty horn relay as required.
(3) Depress the horn switch. There should now be
battery voltage at the horn relay output circuit cavity
of the horn(s) wire harness connector(s). If OK,
replace the faulty horn(s). If not OK, repair the open
horn relay output circuit to the horn relay as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the wire harness connector(s) from
the horn connector receptacle(s) (Fig. 1) .
(3) Remove the screw that secures the horn and
mounting bracket unit(s) to the right fender wheel
house front extension.
(4) Remove the horn and mounting bracket unit(s)
from the right fender wheel house front extension.
Fig. 1 Horns Remove/Install
1 - WIRE HARNESS CONNECTOR
2 - SCREWS
3 - INNER FENDER
4 - LOW NOTE HORN
5 - WIRE HARNESS CONNECTOR
6 - WHEELHOUSE EXTENSION
7 - HIGH NOTE HORN
8H - 2 HORNBR/BE
HORN (Continued)