brakes. The secondary outlet port supplies hydraulic
pressure to the left front and right rear brakes.
POWER BRAKE VACUUM BOOSTER OPERATION
All vehicles use a 270 mm single diaphragm power
brake vacuum booster.
The power brake booster can be identified if
required, by the tag attached to the body of the
booster assembly (Fig. 10). This tag contains the fol-
lowing information: The production part number of
the power booster assembly, the date it was built,
and who was the manufacturer of the power brake
vacuum booster.
NOTE: The power brake booster assembly is not a
repairable component and must be replaced as a
complete assembly if it is found to be faulty in any
way. The check valve located in the power brake
booster (Fig. 10) is not repairable but it can be
replaced as an assembly separate from the power
brake booster.
The power brake booster reduces the amount of
force required by the driver to obtain the necessary
hydraulic pressure to stop vehicle.
The power brake booster is vacuum operated. The
vacuum is supplied from the intake manifold on the
engine through the power brake booster check valve
(Fig. 10) and (Fig. 11).
As the brake pedal is depressed, the power brake
boosters input rod moves forward (Fig. 11). This
opens and closes valves in the power booster, allow-
ing atmospheric pressure to enter on one side of a
diaphragm. Engine vacuum is always present on the
other side. This difference in pressure forces the out-
put rod of the power booster (Fig. 11) out against the
primary piston of the master cylinder. As the pistons
in the master cylinder move forward this creates the
hydraulic pressure in the brake system.The different engine combinations used on this
vehicle require that different vacuum hose routings
to the power brake vacuum booster be used.
All vacuum hoses must be routed from the engine
to the power brake vacuum booster without kinks,
excessively tight bends or potential for damage to the
vacuum hose.
The power brake vacuum booster assembly mounts
on the engine side of the dash panel, and is con-
nected to the brake pedal by the input push rod (Fig.
11). A vacuum line connects the power booster to the
intake manifold. The master cylinder is bolted to the
front of the power brake vacuum booster assembly.
RED BRAKE WARNING LAMP OPERATION
The red Brake warning lamp is located in the
instrument panel cluster and is used to indicate a
low brake fluid condition or that the parking brake is
applied. In addition, the brake warning lamp is
turned on as a bulb check by the ignition switch
every time the ignition switch is turned to the crank
position.
The warning lamp bulb is supplied a 12 volt igni-
tion feed anytime the ignition switch is on. The bulb
is then illuminated by completing the ground circuit
either through the park brake switch, the fluid level
sensor in the master cylinder reservoir, or the igni-
tion switch when it is turned to the crank position.
The Brake Fluid Level sensor is located in the
brake fluid reservoir of the master cylinder assembly.
The purpose of the sensor is to provide the driver
with an early warning that brake fluid level in the
master cylinder fluid reservoir has dropped to below
Fig. 10 Power Brake Booster Identification
Fig. 11 Power Brake Booster Assembly
5 - 8 BRAKESNS
DESCRIPTION AND OPERATION (Continued)
The primary functions of the (CAB) are:
(1) Detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
(2) Illuminate the TRAC lamp in the message cen-
ter on the instrument panel when a traction control
event is occurring.
(3) Control fluid modulation to the wheel brakes
while the system is in an ABS mode or the traction
control system is activated.
(4) Monitor the system for proper operation.
(5) Provide communication to the DRB Scan Tool
while in diagnostic mode.
(6) Store diagnostic information.
(7)The CAB continuously communicates with
the body controller by sending out a message to
the body controller on the CCD Bus. This mes-
sage is used for illumination of the yellow
antilock warning lamp. This is used if the ABS
controller communication is lost in the hard
wire between the body controller and the yel-
low antilock warning lamp. If the body control-
ler does not receive this message from the CAB,
the body controller will illuminate the antilock
yellow warning lamp.
The CAB continuously monitors the speed of each
wheel through the signals generated by the wheel
speed sensors to determine if any wheel is beginning
to lock. When a wheel locking tendency is detected,
the CAB commands the CAB command coils to actu-
ate. The CAB command coils then open and close the
valves in the HCU which modulate brake fluid pres-
sure in some or all of the hydraulic circuits. The CAB
continues to control pressure in individual hydraulic
circuits until a locking tendency is no longer present.
The ABS system is constantly monitored by the
CAB for proper operation. If the CAB detects a fault,
it will turn on the Amber ABS Warning Lamp anddisable the ABS braking system. The normal base
braking system will remain operational.
The CAB contains a self-diagnostic program which
will turn on the Amber ABS Warning Lamp when a
ABS system fault is detected. Faults are then stored
in a diagnostic program memory. There are multiple
fault messages which may be stored in the CAB and
displayed through the DRB Scan Tool. These fault
messages will remain in the CAB memory even after
the ignition has been turned off. The fault messages
can be read and or cleared from the CAB memory by
a technician using the DRB Scan Tool. The fault
occurrence and the fault code will also be automati-
cally cleared from the CAB memory after the identi-
cal fault has not been seen during the next 3500
miles of vehicle operation. Mileage though of the last
fault occurrence will not be automatically cleared.CONTROLLER ANTILOCK BRAKE INPUTS
²Four wheel speed sensors.
²Stop lamp switch.
²Ignition switch.
²System relay voltage.
²Ground.
²Traction Control Switch (If Equipped).
²Diagnostics Communications (CCD)
CONTROLLER ANTILOCK BRAKE OUTPUTS
²C2D Communication To Body Controller And
Instrument Cluster
²ABS warning lamp actuation.
²Traction Control Light (If Equipped).
²Diagnostic communication. (CCD)
ABS WARNING LAMP (YELLOW)
The ABS system uses a yellow colored ABS Warn-
ing Lamp. The ABS warning lamp is located on the
right side of the message center located at the top of
the instrument panel. The purpose of the warning
lamp is discussed in detail below.
The ABS warning lamp will turn on when the CAB
detects a condition which results in a shutdown of
ABS function or when the body controller does not
receive C2D messages from the CAB. When the igni-
tion key is turned to the on position, the ABS Warn-
ing Lamp is on until the CAB completes its self tests
and turns the lamp off (approximately 4 seconds
after the ignition switch is turned on). Under most
conditions, when the ABS warning lamp is on, only
the ABS function of the brake system is affected. The
standard brake system and the ability to stop the car
will not be affected when only the ABS warning lamp
is on.
The ABS warning lamp is controlled by the CAB
and the body controller through a diode located in
the wiring harness junction block. The junction block
is located under the instrument panel to the left of
Fig. 10 Controller Antilock Brake (CAB)
NSBRAKES 5 - 91
DESCRIPTION AND OPERATION (Continued)
INSTRUMENT PANEL AND SYSTEMS
CONTENTS
page page
GENERAL INFORMATION
INTRODUCTION......................... 1
DESCRIPTION AND OPERATION
INSTRUMENT CLUSTER................... 1
DIAGNOSIS AND TESTING
DIAGNOSTIC PROCEDURES................ 2
HEADLAMP SWITCH..................... 2
SELF DIAGNOSTIC TEST.................. 2
TRACTION CONTROL SWITCH............. 17
REMOVAL AND INSTALLATION
BODY CONTROL MODULE (BCM).......... 18
CONVENIENCE BIN - CUP HOLDER......... 17
CONVENIENCE BIN LAMP................ 17
CONVENIENCE BIN TRACK............... 18
GLOVE BOX LAMP AND SWITCH.......... 19
GLOVE BOX LOCK STRIKER.............. 20
GLOVE BOX........................... 19
HEADLAMP SWITCH LAMP(S)............ 21
HEADLAMP SWITCH.................... 20
HVAC CONTROL LAMP.................. 21
INSTRUMENT CLUSTER BACK PANEL...... 21
INSTRUMENT CLUSTER BEZEL............ 21
INSTRUMENT CLUSTER ELECTRONIC
ODOMETER AND TRANSMISSION RANGE
INDICATOR.......................... 19
INSTRUMENT CLUSTER LAMPS........... 22
INSTRUMENT CLUSTER LENS - MECHANICAL
TRANSMISSION RANGE INDICATOR
(PRND21)........................... 19
INSTRUMENT CLUSTER LENS............. 22INSTRUMENT CLUSTER PRINTED CIRCUIT
BOARD.............................. 23
INSTRUMENT CLUSTER SUBDIAL.......... 23
INSTRUMENT CLUSTER SUBDIALÐ
MECHANICAL TRANSMISSION RANGE
INDICATOR.......................... 23
INSTRUMENT CLUSTER WITH ELECTRONIC
TRANSMISSION RANGE INDICATOR...... 23
INSTRUMENT CLUSTER WITH MECHANICAL
TRANSMISSION RANGE INDICATOR...... 24
INSTRUMENT PANEL LEFT END COVER..... 27
INSTRUMENT PANEL LOUVERS........... 27
INSTRUMENT PANEL RIGHT END COVER.... 29
INSTRUMENT PANEL TOP COVER.......... 29
INSTRUMENT PANEL.................... 25
JUNCTION BLOCK...................... 30
KNEE BLOCKER REINFORCEMENT......... 30
LOWER CONSOLE...................... 30
LOWER INSTRUMENT PANEL............. 31
LOWER STEERING COLUMN COVER........ 31
MECHANICAL TRANSMISSION RANGE
INDICATOR.......................... 32
MESSAGE CENTER LAMP................ 32
MESSAGE CENTER...................... 32
OUTLET (12 VOLT) BASE................. 32
OVER STEERING COLUMN BEZEL.......... 32
POWER MIRROR SWITCH LAMP.......... 34
POWER MIRROR SWITCH................ 34
RADIO BEZEL AND HVAC CONTROL........ 34
REAR HEATER-A/C SWITCH LAMP......... 35
REAR HEATER-A/C SWITCH............... 35
TRACTION CONTROL SWITCH............. 35
GENERAL INFORMATION
INTRODUCTION
The instrumentation gauges on NS vehicles are
contained in a subdial assemblies within the instru-
ment cluster. The individual gauges are not serviced
separately. If one of the cluster gauges becomes
faulty the entire subdial would require replacement
and all gauges will have to be calibrated. Refer to the
proper Body Diagnostic Procedure Manual for cali-
bration procedures.
DESCRIPTION AND OPERATION
INSTRUMENT CLUSTER
The mechanical instrument cluster with a tachom-
eter is equipped with a electronic vacuum fluorescent
transmission range indicator (PRND3L), odometer,
and trip odometer display.
The mechanical instrument cluster without a
tachometer is equipped with a cable operated trans-
mission range indicator (PRND21).
NSINSTRUMENT PANEL AND SYSTEMS 8E - 1
The instrument cluster is equipped with the follow-
ing warning lamps.
²Lift Gate Ajar
²Low Fuel Level
²Low Windshield Washer Fluid Level
²Cruise
²Battery Voltage
²Fasten Seat Belt
²Door Ajar
DIAGNOSIS AND TESTING
DIAGNOSTIC PROCEDURES
NS vehicle instrument clusters are equipped with a
self diagnostic test feature to help identify electronic
problems. Prior to any test, perform Self Diagnostic
Test. The self diagnostic system monitors the CCD
bus messages. If an electronic problem occurs, a
Diagnostic Trouble Code (DTC) will be displayed in
the odometer window of the cluster.
The following CCD bus messages are continuously
monitored by the diagnostic system:
²Body Control Module
²Powertrain Control Module
²Transmission Control Module, if equipped
HEADLAMP SWITCH
Using a Digital Multimeter, equipped with a diode
test to perform the Headlamp Switch Test below (Fig.
1).
Switch position possibilities are open (no continu-
ity), continuity, resistance value in ohms, or diode
test. Use the values in the third column to determine
meter setting. If Headlamp Switch is not within spec-
ifications replace as necessary.
The Chrysler Town and Country is available with
optional Automatic Headlamps. For diagnosis, refer
to the proper Body Diagnostic Procedures Manual.
SELF DIAGNOSTIC TEST
To activate self diagnostic program:
(1) With the ignition switch in the OFF position,
depress the TRIP and RESET buttons.
(2) While holding the TRIP and RESET button
turn the ignition switch to the ON position.
(3) Continue to hold the TRIP and RESET buttons
until the word CODE appears in the odometer win-
dows (about five seconds) then release the buttons. If
a problem exists, the system will display Diagnostic
Trouble Codes (DTC's). If no problem exists, the code
999 (End Test) will momentarily appear.
DIM TEST
When CHEC-0 is displayed in the odometer win-
dow, the cluster's vacuum fluorescent (VF) displayswill dim down. If the VF display brightness does no
change, a problem exists in the cluster.
Fig. 1 Headlamp Switch Test
8E - 2 INSTRUMENT PANEL AND SYSTEMSNS
DESCRIPTION AND OPERATION (Continued)
CLUSTER CALIBRATION TABLE
Speedometer Calibration Point
1 ............................0mph(0Km/h)
2 ..........................20mph(40Km/h)
3 ..........................55mph(80Km/h)
4 .........................75mph(120 Km/h)
Tachometer Calibration Point
1....................................0rpm
2 .................................1000 rpm
3 .................................3000 rpm
4 .................................6000 rpm
Fuel Gauge Calibration Point
1.................................Empty (E)
2 .................................1/8 Filled
3 .................................1/4 Filled
4...................................Full (F)
Temperature Gauge Calibration Point
1 ..................................Cold (C)
2...............................Low Normal
3 ..............................High Normal
4...................................Hot (H)
CALIBRATION TEST
When CHEC-1 is displayed in the odometer win-
dow, each of the cluster's gauge pointers will move
sequentially through each calibration point. The Cal-
ibration Table contains the proper calibration points
for each gauge. If the gauge pointers are not cali-
brated, a problem exists in the cluster. If any gauge
is out of calibration it will have to be calibrated using
a scan tool (DRB III). Refer to the proper Body Diag-
nostic Procedure Manual for calibration procedures.
ODOMETER SEGMENT TEST
When CHEC-2 is displayed in the odometer win-
dow, each digit of the odometer will illuminate
sequentially. If a segment in the odometer does not
illuminate normally, a problem exists in the display.
ELECTRONIC TRANSMISSION RANGE
INDICATOR SEGMENT TEST
When CHEC-3 is displayed in the odometer win-
dow, each segment of the transmission range indica-
tor will illuminate sequentially. If a segment in the
transmission range indicator does not illuminate nor-
mally, a problem exists in the display board.
CONDITIONS
Refer to the following tables:
²Instrument Cluster
²Speedometer
²Tachometer
²Fuel Gauge
²Temperature Gauge
²Odometer
²Electronic Transmission Range Indicator
(PRND3L)
²Mechanical Transmission Range Indicator
(PRND21)
for possible/problems/causes and corrections.
INSTRUMENT CLUSTER DTC TABLE
DTC DESCRIPTION
110 Memory Fault in cluster
111 Calibration fault in cluster
905 No CCD bus messages from TCM
921 Odometer fault from BCM
940 No CCD bus messages from PCM
999 End of Codes
INSTRUMENT CLUSTER DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
INSTRUMENT CLUSTER
INOPERATIVE-NO
RESPONSENo CCD bus messages
from the Body Control
Module (BCM).1. Use a scan tool to check the BCM. If OK, look for
another possible cause for cluster failure. If not OK,
refer to the proper Body Diagnostic Procedure Manual.
Spread terminal(s) on
wiring harness cluster
connector.1. Remove cluster from instrument panel and check
wiring harness connector for spread terminal. If OK,
look for another possible cause for the cluster failure. If
not OK, repair connector.
Body Control Module
(BCM) is not receiving
proper input from the
ignition switch.1. Use a scan tool to verify ignition switch status into
the BCM. If not OK, go to Step (2). If OK, look at
another possible cause of failure.
2. Check ignition switch function and wiring.
Internal cluster failure. 1. Replace main cluster pc board and use a scan tool
to calibrate cluster.
NSINSTRUMENT PANEL AND SYSTEMS 8E - 3
DIAGNOSIS AND TESTING (Continued)
SPEEDOMETER DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO POINTER
MOVEMENT1. Internal cluster failure. 1. (a) Perform cluster self diagnostic test and check for
fault codes.
²If speedometer pointer moves to calibration points
during test and fault codes 110 or 111 don't appear in
the odometer display then failure is not in the cluster.
Look for another possible cause of failure.
²If the pointer doesn't move during test, go to Step
(b).
²If fault code 110 is displayed in the odometer, go to
Step (b).
²If fault code 111 is displayed in the odometer then go
to Step (f).
²If fault codes 905, 920, or 940 are displayed in the
odometer display refer to the fault code chart to identify
which module is causing the fault and repair module.
(b) Replace main cluster pc board. Go to Step (c).
(c) Connect cluster into instrument panel wiring
harness. Place it back into the proper position in the
instrument panel. Put in the top two mounting screws to
hold the cluster in place. DO NOT COMPLETELY
INSTALL CLUSTER TO INSTRUMENT PANEL UNTIL
UNIT IS CALIBRATED AND TESTED. Go to Step (d).
(d) Use a scan tool to calibrate cluster and perform Self
Diagnostic Test. If OK, complete installation. If not OK,
go to Step (e).
(e) Replace subdial assembly and use a scan tool to
calibrate cluster. If not OK, look at another possible
cause for the speedometer failure.
(f) Use a scan tool to calibrate speedometer and
perform Self Diagnostic Test. If OK, stop. If not OK, go
to Step (b).
2. No speed CCD Bus
Message or Zero mph
CCD Speed Bus
Message.2. (a) Check the Body Control Module (BCM) using a
scan tool. If OK, go to Step (b). If not OK, refer to the
BCM section of the service manual to repair the BCM.
(b) Check the Powertrain Control Module (PCM) using
a scan tool. If OK, go to Step (c). If not OK, refer to the
PCM section of the service manual to repair the PCM.
(c) Check the speed signal input into the PCM. The
speed signal originates from one of the following
sources:
²A distance sensor for vehicles with 3 speed automatic
transmission. Check continuity from distance sensor to
PCM. If OK, replace distance sensor. If not OK, repair
wiring.
²The Electronic Transmission Control Module (TCM)
for vehicles with the 4 speed electronic transmissions.
Check continuity from TCM to PCM. If OK, use a scan
tool to check TCM. Refer to the electronic TCM section
of the service manual to repair the TCM. If not OK,
repair wiring.
8E - 4 INSTRUMENT PANEL AND SYSTEMSNS
DIAGNOSIS AND TESTING (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
ERRATIC POINTER
MOVEMENT1. Erratic Message from
another Module.1. (a) Check the BCM using a scan tool If OK, go to
Step (b). If not OK, refer to the BCM section of the
service manual to repair the BCM.
(b) Check the PCM using a scan tool. If OK, go to Step
(c). If not OK, refer to the PCM section of the service
manual to repair the PCM.
(c) Check the speed signal input into the PCM. The
speed signal originates from one of the following
sources:
²A distance sensor for vehicles with 3 speed automatic
transmission. Check continuity from distance sensor to
PCM. If OK, replace distance sensor. If not OK, repair
wiring.
²The Electronic Transmission Control Module (TCM)
vehicles with the 4 speed electronic transmissions.
Check continuity from TCM to engine controller. If OK,
use a scan tool to check TCM. Refer to the electronic
section of the service manual to repair the TCM. If not
OK, repair wiring.
2. Internal Cluster Failure. 2. (a) Perform cluster self diagnostic test and check for
fault codes.
²If the pointer moves during test but still appears
erratic and fault codes 110 or 111 don't appear in the
odometer display, then go to Step (b).
²If fault code 110 is displayed in the odometer, go to
Step (e).
²If fault code 111 appears in the odometer display go
to Step (d).
²If fault codes 905, 920, or 940 are displayed in the
odometer display refer to the fault code chart to identify
which module is causing the fault and repair module.
(b) Replace cluster subdial assembly. To Step (c).
(c) Connect cluster into instrument panel wiring
harness. Place it back into the proper position in the
instrument panel. Put in the top two mounting screws to
hold the cluster in place. DO NOT COMPLETELY
INSTALL CLUSTER TO INSTRUMENT PANEL UNTIL
UNIT IS CALIBRATED AND TESTED. Go to Step (d).
(d) Use a scan tool to calibrate cluster and perform Self
Diagnostic Test. If OK, continue installation. If not OK,
go to Step (e).
Replace main cluster pc board and use a scan tool to
calibrate cluster. If not OK, look at another possible
cause for the speedometer failure.
NSINSTRUMENT PANEL AND SYSTEMS 8E - 5
DIAGNOSIS AND TESTING (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
SPEEDOMETER
INACCURATE.1. Speedometer Out of
Calibration.1. (a) Perform Cluster Self Diagnostic Test.
²If speedometer is accurate to the calibration points
then look for another possible cause of inaccuracy.
²If speedometer is not accurate to the calibration
points, go to Step (b).
(b) Use a scan tool to calibrate speedometer.
2. Wrong Speedometer
Pinion Size For Tire Size.2. (a) If vehicle has a 4 speed electronic transmission
go to Step (c). Otherwise go to Step (b).
(b) Check if correct speedometer pinion is being used
with tires on vehicle. Refer to transmission section of
manual for test and repair procedure.
²If the incorrect pinion is in transmission then replace
with correct pinion.
²If the correct pinion is in the transmission calibrate
speedometer using a scan tool to correct for the
inaccuracy.
(c) use a scan tool to check the TCM to see if the
correct tire size has been programmed into the TCM.
²If the incorrect tire size was selected, select the
proper tire size.
²If the correct tire size was selected, calibrate
speedometer to correct for the inaccuracy.
3. Bad Speed Sensor. 3. Refer to the proper section of the service manual for
test and repair procedure.
8E - 6 INSTRUMENT PANEL AND SYSTEMSNS
DIAGNOSIS AND TESTING (Continued)