1993 CHEVROLET PLYMOUTH ACCLAIM fuse

(4) Provide communication to the DRB II while in
the Antilock brakes diagnostic mode. The CAB continuously monitors the speed of each
wheel, through the signals generated at the Wheel
Speed Sensors. This is used to determine if any
wheel of the vehicle is beginning to lock-up (skid)
when the brakes are applied. When a wheel locking
tendency is detected during brake apply. The CAB
commands the appropriate Build/Decay valves to
modulate brake fluid pressure in some or all of the
hydraulic circuits. The CAB continues to control
pressure in individual hydraulic circuits until a lock-
ing 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 Antilock Warning Lamp
and disable the ABS brake system. The normal Non
ABS brake system will remain operational. The CAB contains a self-diagnostic program which
will turn on the Amber Antilock Warning Lamp
when a system fault is detected. Faults are stored in
a diagnostic program memory. There are 16 fault
codes which may be stored in the CAB and displayed
through the DRB II. These fault codes will remain in
the CAB memory even after the ignition has been
turned off. The fault codes can be cleared by using
the DRB II diagnostics tester, or they will be auto-
matically cleared from the memory after (50) ignition
switch on/off cycles.
CONTROLLER ANTILOCK BRAKE (INPUTS)
² Four wheel speed sensors.
² Stop lamp switch.
² Ignition switch.
² System relay voltage.
² Ground.
² Pump/Motor Relay Monitor
² Diagnostics Communications
CONTROLLER ANTILOCK BRAKE (OUTPUTS)
²4 Build/Decay valves.
² Antilock warning lamp.
² System relay actuation.
² Diagnostic communication.
² Pump/Motor relay actuation
DIAGNOSTIC CONNECTOR
The Bendix Antilock 4 Brake System diagnostic
connector is located under the fuse panel access
cover. The access cover is located on the lower sec-
tion of the instrument panel to the left side of the
steering column. The diagnostics connector is a blue
6 way connector see (Fig. 9).
ANTILOCK SYSTEM RELAYS AND WARNING LAMPS
SYSTEM RELAY
The ABS Modulator Valves are powered through
the System Relay which is located on a bracket
mounted to the CAB (Fig. 10). The System Relay
provides power to the CAB for modulator valve oper-
ation (pins 47 and 41) after the startup cycle when
the ignition is turned on.
Fig. 8 CAB Location
Fig. 9 Antilock Diagnostic Connector Location
Fig. 10 System Relay Location On The CAB
Ä ANTILOCK 4 BRAKE SYSTEM 5 - 19

earlier in this service manual supplement. Then follow
the diagnostic procedures outlined in this section. Many conditions that generate customer complaints
may be normal operating conditions, but are judged to
be a problem due to not being familiar with the ABS
system. These conditions can be recognized without
performing extensive diagnostic work, given adequate
understanding of the operating principles and perfor-
mance characteristics of the ABS system.
DEFINITIONS
Several abbreviations are used in this manual. They
are presented here for reference.
² CABÐController Antilock Brake
² ABSÐAntilock Brake System
² PSIÐPounds per Square Inch (pressure)
² WSSÐWheel Speed Sensor
² ACÐAlternating Current
ABS COMPUTER SYSTEM SERVICE PRECAUTIONS
The ABS system uses an electronic control module,
the CAB. This module is designed to withstand normal
current draws associated with vehicle operation. How-
ever care must be taken to avoid overloading the CAB
circuits. In testing for open or short circuits, do
not ground or apply voltage to any of the circuits
unless instructed to do so by the appropriate
diagnostic procedure. These circuits should only be
tested using a high impedance multi-meter, special
tools or the DRB II tester as described in this section.
Power should never be removed or applied to any
control module with the ignition in the ON position.
Before removing or connecting battery cables, fuses, or
connectors, always turn the ignition to the OFF posi-
tion.
ABS GENERAL SERVICE PRECAUTIONS
TEST DRIVING ABS COMPLAINT VEHICLES
Most ABS complaints will require a test drive as a
part of the diagnostic procedure. The purpose of the
test drive is to duplicate the condition. Remember conditions that result in the turn-
ing on of the Red Brake Warning Lamp may
indicate reduced braking ability. The following
procedure should be used to test drive an ABS
complaint vehicle. Before test driving a brake complaint vehicle, note
whether the Red or Amber Brake Warning Lamp is
turned on. If the Red Brake Warning Lamp, is
turned on, refer to the base brake Control Valves
Section in the Front Wheel Drive, chassis service
manual. If the Amber Antilock Warning light was or
is on, read record and erase the faults. While the
Amber ABS Warning Lamp is on the ABS system is
not functional. The standard brake system and abil- ity to stop the car is not affected, if only the Amber
Antilock Warning Lamp is on.
(1) Turn ignition key to the off position and then
back to the on position. Note whether the Amber ABS
Warning Lamp continues to stay on. If it does refer to
the 1994 Bendix Antilock 4 Brake System Diagnostic
Manual for the required diagnostic test procedures. (2) If the Amber ABS Warning Lamp goes out, shift
vehicle into gear and drive car to a speed of 5 mph to
complete the ABS drive-off cycle. If at this time, the
Amber ABS Warning Lamp goes on refer to the 1994
Bendix Antilock 4 Brake System Diagnostic Manual. (3) If the Amber ABS Warning Lamp remains OUT,
continue to drive the vehicle a short distance. During
this test drive be sure that the vehicle achieves at least
25 mph. Brake to at least one complete stop and again
accelerate to 25 mph. (4) If a functional problem with the ABS system is
determined while test driving a vehicle. Refer to the
Bendix Antilock 4 Brake System Diagnostics Manual
for required diagnostic test procedures and proper use
of the DRB II tester.
ABS BRAKE SYSTEM ON VEHICLE SERVICE
The following are general precautions which
should be observed whenever servicing and or
diagnosing the ABS system and other vehicle
electronic systems. Failure to observe these pre-
cautions may result in ABS system damage. (1) If welding work is to be performed on a vehicle
using an arc welder. The wiring harness connector
should be disconnected from the CAB before beginning
any welding operation. (2) The CAB 60 way connector and modulator as-
sembly 10 way connector, should never be connected or
disconnected with the ignition in the on position. (3) Some components of Bendix Antilock 4 Brake
System assemblies can not be serviced separately from
the assembly and will require replacement of the
complete assembly for servicing. Do not disassemble
any component which is designated as non-serviceable.
CAUTION: Brake fluid will damage painted surfaces.
If brake fluid is spilled on any painted surfaces, wash
off with water immediately.
WHEEL SPEED SENSOR CABLES
Proper installation and routing of the Wheel Speed
Sensor Cables is critical to continued system opera-
tion. Be sure that cables are installed, routed and
clipped properly. Failure to install speed sensor ca-
bles as shown in the on car service section of this
Ä ANTILOCK 4 BRAKE SYSTEM 5 - 23

BENDIX ANTILOCK 4 MODULATOR ASSEMBLY BLEEDING PROCEDURE
(1) Assemble and install all brake system compo-
nents on the vehicle, making sure all hydraulic fluid
lines are installed and properly torqued. (2) Bleed the base brake system, using ONLYthe
bleeding procedure outlined in the Service Adjust-
ments section of this service manual supplement. To perform the bleeding procedure on the ABS modu-
lator assembly, the battery, battery tray and acid shield
must be removed from vehicle. Then reconnect the
vehicle's battery to vehicle's battery cables, using
ONLY approved battery jumper cables. (3) Connect the DRB Diagnostics Tester to the vehi-
cle's diagnostics connector. The vehicle diagnostic con-
nector is located behind the fuse panel access cover on
the lower section of the dash panel left of the steering
column. The diagnostic connector is a blue 6 way
connector. (4) Using the DRB check to make sure the CAB does
not have any stored fault codes. If it does, remove them
using the DRB.
WARNING: WHEN BLEEDING THE MODULATOR AS-
SEMBLY WEAR SAFETY GLASSES. A CLEAR BLEED
TUBE MUST BE ATTACHED TO THE MODULATOR
BLEED SCREWS AND SUBMERGED IN A CLEAR
CONTAINER FILLED PART WAY WITH FRESH CLEAN
BRAKE FLUID. DIRECT THE FLOW OF BRAKE FLUID
AWAY FROM THE PAINTED SURFACES OF THE VE-
HICLE. BRAKE FLUID AT HIGH PRESSURE MAY
COME OUT OF THE BLEEDER SCREWS, WHEN
OPENED.
When bleeding Antilock modulator assembly, the
following bleeding sequence MUSTbe followed to
insure a complete bleeding of all air from the Antilock
brake, and base brake hydraulic systems. The modu-
lator assembly can ONLY be bled using a manual
bleeding procedure to pressurize the hydraulic
system.
MODULATOR ASSEMBLY CIRCUIT BLEEDING PROCEDURE AND SEQUENCE
1 MODULATOR PRIMARY CHECK VALVE CIRCUIT
Note: To bleed hydraulic circuits of the Bendix
Antilock 4 Brake System modulator assembly,
the aid of a second mechanic or helper will be
required to pump the brake pedal. (1) Install a clear bleed tube (such as Tygon) on
primary check valve circuit bleed screw (Fig. 1). Then
install bleed tube into a clear container partially filled
with fresh clean brake fluid (Fig. 1). (2) Pump brake pedal several times, then apply and
hold a constant medium to heavy force on brake pedal. (3) Open primary check valve circuit bleed screw
(Fig. 1) at least 1 full turn to ensure an adequate flow
of brake fluid. Continue bleeding primary check valve
circuit until brake pedal bottoms. (4) After brake pedal bottoms, close and tighten
bleed screw. Then release brake pedal. Do not release
brake pedal prior to closing and tightening bleed
screw. (5) Continue bleeding modulator assembly, repeat-
ing steps 2 through 4 until a clear, bubble free flow of
brake fluid is evident. (6) When all air is bled from primary check valve
circuit, tighten bleed screw and remove bleed hose
from bleed screw. Do not remove bleed hose before
tightening bleed screw, air may re-enter modula-
tor. (7) Torque modulator assembly primary bleed screw
to9N Im (80 in. lbs.).
2 MODULATOR SECONDARY CHECK VALVE CIRCUIT (1) Move clear bleed tube to secondary check valve
circuit bleed screw (Fig. 2). Then install bleed tube into
a container partially filled with fresh clean brake fluid
(Fig. 2). (2) Pump brake pedal several times, then apply and
hold a constant medium to heavy force on brake pedal. (3) Open secondary check valve circuit bleeder screw
(Fig. 2), at least 1 full turn to ensure an adequate flow
of brake fluid. Continue to bleed secondary check valve
circuit until the brake pedal bottoms.
Fig. 1 Bleeding Modulator Assembly Primary Check Valve Circuit
5 - 26 ANTILOCK 4 BRAKE SYSTEM Ä

IGNITION OFF DRAW (IOD)
GENERAL INFORMATION
A normal electrical system will draw from 5 to 30
milliamperes from the battery. This is with the ignition
in the OFF position, and all non-ignition controlled cir-
cuits in proper working order. The amount of IOD will
depend on body model and electrical components. A ve-
hicle that has not been operated for an extended period
of approximately 20 days may discharge the battery to
an inadequate level. In this case, the Main Fusible Link
Connector should be disconnected. The Main Fusible
Link connector is located rearward of the battery on the
engine wiring harness (Fig. 19).
If the IOD is over 30 milliamperes, the defect must
be found and corrected before condemning the bat-
tery. Usually, the battery can be charged and re-
turned to service (Fig. 16).
IGNITION OFF DRAW (IOD) TESTS
VEHICLES WITHOUT ELECTRONIC AUTOMATIC TRANSMISSION/LOAD LEVELINGSUSPENSION OR ALARM SYSTEMS
Testing for HIGHER AMPERAGE IOD must be
performed first to prevent damage to most milliamp
meters. A standard 12 volt test light and a milliamp meter
that is equipped with two leads will be used for the
following tests. The milliamp meter should be able to
handle up to two amps.
(1) Verify that all electrical accessories are OFF.
Turn off all lights, close trunk lid, close glove box door,
turn off sun visor vanity lights, close all doors and re- move ignition key. Allow the Illuminated Entry System
if equipped to time out in approximately 30 seconds.
(2) Verify the engine compartment lamp bulb is
working by opening/closing hood. Remove the lamp. (3) Disconnect negative battery cable (Fig. 15).
(4) Connect a typical 12 volt test light between the
negative cable clamp and the negative battery post (Fig.
19). The test light may be brightly lit for up to three
minutes or may not be lit at all. This depending on the
body model or electronic components on the vehicle. (a) The term brightly used throughout the follow-
ing tests. This implies the brightness of the test light
will be the same as if it were connected across the
battery posts. This would be with a fully charged bat-
tery.
(b) The test light or the milliamp meter MUST
be positively connected to the battery post and the
battery cable during all IOD testing. (c) Do not allow the test light or the milliamp
meter to become disconnected during any of the
IOD tests. If this happens, the electronic timer
functions will be started and all IOD tests must be
repeated from the beginning. Clamp the test light
at both ends to prevent accidental disconnection.
(d) After three minutes time has elapsed, the test
light should turn OFF or be dimly lit depending on
the electronic components on the vehicle. If the test
light remains BRIGHTLY lit, do not disconnect test
light. Disconnect each fuse or circuit breaker until
test light is either OFF or DIMLY lit. Refer to the
Front Wheel Drive Car Wiring Diagrams Service
Manual. This will eliminate higher amperage IOD. It
is now safe to install the milliamp meter without
damage to the meter to check for low amperage IOD.
(e) Possible sources of high IOD are usually ve-
hicle lamps trunk lamp, glove compartment, lug-
gage compartment, etc.. (f) If test light is still brightly lit after discon-
necting each fuse and circuit breaker, disconnect
the wiring harness from the generator. Refer to
Generator Testing. Do not disconnect test light.
CAUTION: This last test has higher amperage IOD and
must be performed before going on with low amper-
age IOD tests. The higher amperage IOD must be elim-
inated before hooking up milliamp meter to check for
low amperage IOD. If higher amperage IOD has not
been eliminated, milliamp meter may be damaged.
Most milliamp meters will not handle over one or two
amps. Do not hook up meter if test light is glowing
brightly. Refer to maximum amperage specifications
and instructions supplied with milliamp meter.
After higher amperage IOD has been corrected, low
amperage IOD may be checked. The MAXIMUM IOD=
30 MILLIAMPERES.
Fig. 19 IOD Test
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 9

(5) With test light still connected, connect milli-
amp meter between battery negative post and nega-
tive battery cable (Fig. 20). Do not open any doors or
turn on any electrical accessories with the test light
disconnected and the milliamp meter connected.
Meter may be damaged.
(6) Disconnect test light. Milliamp meter reading
should be less than 30 milliamperes. If low amperage
IOD is not within specifications, disconnect: (a) The 60 way connector at the Powertrain Con-
trol Module located outboard of the battery. Refer
to Group 8D, Ignition for more information. (b) The 25 way connectors on the Body Control-
ler if equipped. (c) The circuits to the clock and radio.
(d) The wiring harness from the generator. Refer
to Generator Testing.
Check each component until excessive IOD is found.
Each time the test light or milliamp meter is dis-
connected and connected, all electronic timer func-
tions will be activated. Tests must be repeated from
the beginning. Test light or meter MUST remain connected for all
tests.
VEHICLES EQUIPPED WITH ELECTRONIC AUTOMATIC TRANSMISSION, LOADLEVELING SUSPENSION, OR ALARM SYSTEM
This vehicles will have temporary high IOD of 15
amps or more for up to 65 minutes. This higher IOD can often mask another problem and should be con-
sidered when performing IOD testing. Testing for higher IOD will be the same as in the
previous IOD tests. However, certain additional pro-
cedures should be followed.
² WITH ALARM SYSTEM: After disconnecting bat-
tery and hooking up test light, cycle the key lock on
the driver's door to disarm the alarm. The parking
lamps should stop flashing. Also locate the Power Distribution Center. This
Center is located in front of the left front strut tower
(Fig. 21). Remove the cover from the Center and re-
move the 50 amp fuse.
² WITH ELECTRONIC AUTOMATIC TRANSMIS-
SION: If equipped with this option, and high or low
IOD is suspected, allow an additional 25 minutes
minimum of electronic shut off time. To defeat the timer, disconnect the 60-way connec-
tor on the Transmission Controller. This controller is
located on the right inner fender.
² WITH AUTOMATIC LOAD LEVELING SYSTEM:
If equipped with this option, and high or low IOD is
suspected, allow an additional 65 minutes minimum
of electronic shut off time. To defeat the timer, open the trunk lid, locate the
Automatic Load Leveling computer, located inside
right rear wheel house, and disconnect the 11-way
connector. Close the trunk lid. If equipped with an electrical trunk closing feature,
temporarily install a heavy gauge jumper wire be-
tween the disconnected negative cable and the nega-
tive battery post. When this jumper is installed the
trunk lid should automatically close. Do not discon-
nect the test light as all electronic timing features
will be activated and all IOD tests must be repeated
from the beginning. Remove the temporarily installed jumper wire.
Fig. 20 Low Amperage IOD Test
Fig. 21 Power Distribution Center
8A - 10 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS Ä

OVERHEAD CONSOLE
CONTENTS
page page
AA BODY .............................. 1
AC AND AY BODY ....................... 6 AG AND AJ BODIES
.................... 13
AP BODY ............................. 21
GENERAL INFORMATION AA BODY
INDEX
page page
Ambient Temperature Sensor ................ 6
Compass Calibration ....................... 2
Compass Diagnostics ...................... 5
Compass Module Replacement ............... 6
Demagnetizing Procedure ................... 4 Map Reading Lamps
....................... 1
Overhead Console Replacement .............. 5
Self-Diagnostic Test ....................... 5
Thermometer and Compass Operation ......... 1
Variance ................................ 2
MAP READING LAMPS
The map reading and rear passenger lamps are
turned on and off by pressing their individual switch
marked LAMP. These same lamps also serve as cour-
tesy lamps whenever a door is opened, the illumi-
nated entry system is activated, or the headlamp
switch is turned fully clockwise.
LAMP REPLACEMENT
(1) Remove lens by inserting a large paper clip or
wire, with a hook on the end, into the hole in the
lens and pull downward (Fig. 1).
(2) Remove lamp by pulling firmly toward front of
vehicle. (3) Install new lamp by pushing firmly into recep-
tacle. (4) Snap lens into position taking care to orient
the tabs on the lens with the slots in the housing and
snap into position.
LAMP TEST
(1) Close vehicle doors.
(2) Press each lamp switch button (Fig.2). Right
hand button should light passenger side lamp and
left hand button should light drivers side lamp front
or rear. (3) If any of the lamps fail to illuminate, open ve-
hicle doors: (a) If lamp does not illuminate check for a
burned out lamp. If lamp is OK, check fuse and
wire connectors. (b) If lamp illuminates when doors are open
check switch.
THERMOMETER AND COMPASS OPERATION
The ignition switch must be in the ON or ACCES-
SORY position before the temperature and compass
reading can be displayed. The Comp/Temp switch, lo-
cated left of the display module, turns the display on
and off. The US/Metric switch, located right of the dis-
play, changes the temperature reading from Fahrenheit
to Celsius. Should the compass blank out and the CAL
symbol only light, demagnetizing may be necessary.
The compass is a flux-gate system which, is inte-
gral to the console. The temperature readout is con-
nected to a thermistor sensor which, located on the
front lower radiator closure panel.Fig. 1 Overhead Console Lens Removal
Ä OVERHEAD CONSOLE 8C - 1

MECHANICAL/ELECTRONIC CLUSTER REMOVAL
CLUSTER BEZEL REMOVAL
(1) On column shift vehicles, place column shifter
to neutral position. (2) On tilt steering column vehicles, adjust tilt
range to lowest position. (3) Pull cluster bezel rearward to disengage 11
clips (Fig. 10).
(4) Remove cluster bezel.
(5) For installation reverse above procedures.
CLUSTER MASK AND LENS REMOVAL
(1) Remove cluster, radio and rear window defog-
ger bezels (Fig. 10). (2) Remove four cluster to panel screws.
(3) Pull cluster assembly rearward. Vehicles with
column shift use care to not damage transmission
range indicator guide tube. (4) Remove four screws holding the cluster mask to
cluster housing (Fig. 11).
(5) Pull cluster mask and lens rearward to remove.
(6) For installation reverse above procedures.
CLUSTER ASSEMBLY
REMOVALÐCLUSTER WITH TRANSMISSION RANGE
INDICATOR FROM STEERING COLUMN
(1) Disconnect battery to assure no air bag system
fault codes are stored. (2) Remove cluster bezel (Fig. 10).
(3) On column shift vehicle: (Fig. 12 through 15).
(a) Remove lower steering column cover (Fig.
16). Release guide tube from behind fuse block.
Fig. 10 Cluster Bezel
Fig. 11 Cluster Mask and Lens
Fig. 12 Transmission Range Indicator Step 1
Fig. 13 Transmission Range Indicator Step 2
Ä INSTRUMENT PANEL AND GAUGES 8E - 5

(b) Place gear shift lever in neutral or park.
(c) Remove guide tube from behind fuse block
and disconnect cable eyelet from column actuating
arm. (d) Release lock bar on column insert, squeeze
legs together and remove from column (Fig. 14). (e) Secure insert and cable guide out of the way.
(4) Remove the rear window defogger bezel and ra-
dio bezel. (5) Remove the upper steering column cover. (6) Remove the four screws attaching cluster hous-
ing to the base panel. (7) Pull cluster rearward, reach behind cluster and
disconnect the two wiring harnesses. (8) Remove cluster assembly.
INSTALLATION (1) Connect wiring harnesses.
(2) Position cluster and secure to base panel with
four screws. (3) On column shift vehicles (Fig. 12 through 15):
Fig. 15 Transmission Range Indicator Step 4
Fig. 16 Instrument Panel Bezels
Fig. 14 Transmission Range Indicator Step 3
8E - 6 INSTRUMENT PANEL AND GAUGES Ä