1993 CHEVROLET DYNASTY turn signal

PUMP/MOTOR ASSEMBLY
NOTE: The (CAB) does not control the opera-
tion of the pump/motor assembly. The Pump/Motor Assembly is mounted to the tran-
saxle below the hydraulic assembly,(Fig. 3). Integral to
the Pump/Motor Assembly is an accumulator using a
sliding piston configuration with a nitrogen pre-charge
of 3,172 kPa (460 psi.) The Pump/Motor is an electri-
cally driven pump that takes low pressure brake fluid
from the hydraulic assembly fluid reservoir and pres-
surizes it. The pressurized fluid is then stored in the
piston accumulator and hydraulic bladder accumulator
for power assist and Anti-Lock Braking. Operation of
the Pump/Motor is controlled by the Dual Function
Pressure Switch through the Pump/Motor Relay. The
(CAB) does NOT control the Pump/Motor activa-
tion. Rubber isolators are used to mount the pump to
its bracket for noise isolation. The Pump/Motor Assem-
bly is connected to the Hydraulic Assembly with a low
pressure return hose and a high pressure hose. A filter
is located in the low pressure return line.
WHEEL SPEED SENSORS
One Wheel Speed Sensor (WSS), is located at each
wheel (Fig. 4, 5 and 6) and sends a small (AC) electrical
signal to the control module (CAB). This signal is
generated by magnetic induction. The magnetic induc-
tion is created when a toothed sensor ring (Tone Wheel)
passes by the stationary magnetic (Wheel Speed Sen-
sor). The (CAB) converts the (AC) electrical signal
generated at each wheel into a digital signal. If a wheel
locking tendency is detected, the (CAB) will then
modulate hydraulic pressure to prevent the wheel(s)
from locking. The front Wheel Speed Sensor (Fig. 4) is mounted to
a boss on the steering knuckle, for both the Front Wheel Drive and All Wheel Drive applications. The
Tone Wheel is part of the outboard constant velocity
joint housing. The Rear Wheel Speed Sensor, is mounted to the
caliper mounting adapter (Fig. 5). The rear Tone
Wheel is an integral part of the rear disc brake rotor
hub (Fig. 6). The speed sensor, to tone wheel air gap on all ap-
plications is NOT adjustable. All 4 of the vehicles, Wheel Speed Sensors are ser-
viced individually as replaceable components. The Front Wheel Drive front Tone Wheels are ser-
viced as an assembly with the front outboard con-
Fig. 3 Pump/Motor Assembly And Heat Shield
PRESSURE SWITCH AND PRESSURE TRANSDUCER WIRING
Ä ANTI-LOCK 10 BRAKE SYSTEM 5 - 79

The primary functions of the (CAB) are:
² (1) Detect wheel locking tendencies.
² (2) Control fluid modulation to the brakes while in
Anti-Lock mode.
² (3) Monitor the system for proper operation.
² (4) Provide communication to the DRB II while in
diagnostic mode. The (CAB) continuously monitors the speed of each
wheel, through the signals generated at the Wheel
Speed Sensors, to determine if any wheel is begin-
ning to lock. When a wheel locking tendency is de-
tected, the (CAB) will isolate the master cylinder
from the wheel brakes. This is done by activating the
Isolation Valves. The (CAB) then commands the ap-
propriate Build or Decay valves to modulate brake
fluid pressure in some or all of the hydraulic circuits.
The fluid used for modulation comes from the booster
servo circuit. The (CAB) continues to control pres-
sure 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 can disable the Anti-Lock braking function.
Depending on the fault, the (CAB) will light one or
both of the brake warning lamps. The (CAB) contains a System Diagnostic Program
which triggers the brake system warning lamps
when a system fault is detected. Faults are stored in
a diagnostic program memory. There are 19 fault
codes that 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. These fault codes will remain in memory
until they are cleared with the DRB II, or automati-
cally erased from the memory after (50) ignition
switch on/off cycles.
CONTROLLER ANTI-LOCK BRAKE (INPUTS)
² Four wheel speed sensors.
² Boost pressure transducer.
² Primary pressure transducer.
² Low fluid level switch.
² Differential pressure switch.
² Parking brake switch.
² Dual function pressure switch (warning pressure
only)
² Stop lamp switch.
² Ignition switch.
² System relay voltage.
² Ground.
² Low Accumulator
CONTROLLER ANTI-LOCK BRAKE (OUTPUTS)
²Ten modulator valves-3 decay, 3 build and 4 isola-
tion.
² Red Brake warning lamp.
² Amber Anti-Lock Warning Lamp.
² System relay actuation. ²
Diagnostic communication.
ABS SYSTEM DIAGNOSTIC CONNECTOR
The Bendix Anti-Lock system diagnostic connector
is located under the lower dash panel or in the area
of the fuse box (Fig. 8). The fuse box is located be-
hind the access panel that is on the bottom portion of
the dash panel, left of the steering column. The diag-
nostics connector is a blue 6 way connector.
ANTI-LOCK SYSTEM RELAYS AND WARNING
LAMPS
PUMP/MOTOR RELAY
Pump/Motor power is supplied by the Pump/Motor
Relay. The Pump/Motor relay is located inside the
Power Distribution Center (PDC). The relay coil is
energized by a ground from the Dual Function Pres-
sure Switch. See (Fig. 9) for the location of the pump/
motor relay in the (PDC).
SYSTEM RELAY
The (ABS) Modulator Valves and Anti-Lock Warn-
ing Lamp Relay are controlled through a System Re-
lay. The System relay is located on the top left inner
fender behind the headlight (Fig. 10). The system re-
lay provides power to the (CAB) for modulator valve
operation (pins 47 and 50) after the start-up cycle
when the ignition is turned on.
ANTI-LOCK WARNING LAMP RELAY
The Anti-Lock Warning Lamp is controlled by the
Yellow Light Relay. See (Fig. 10) for location behind
the left headlight. With the relay de-energized, the
lamp is lit. When the system relay is energized by
Fig. 8 A.B.S. Diagnostic Connector Location
5 - 82 ANTI-LOCK 10 BRAKE SYSTEM Ä

CONTROLLER ANTI-LOCK BRAKE (CAB)
The Anti-Lock Brake Controller is a small micro-
processor based device which monitors the brake sys-
tem and controls the system while it functions in
Anti-Lock mode. The CAB is mounted on the top of
the right front frame rail and uses a 60-way system
connector (Fig. 7). The power source for the CAB is
through the ignition switch in the Run or On posi-
tion. THE CONTROLLER ANTI-LOCK BRAKE
(CAB) IS NOT ON THE CCD BUS The primary functions of the (CAB) are:
(1) Detect wheel locking tendencies.
(2) Control fluid modulation to the brakes while in
Anti-Lock mode. (3) Monitor the system for proper operation.
(4) Provide communication to the DRB II while in
diagnostic mode. The (CAB) continuously monitors the speed of each
wheel, through the signals generated at the Wheel
Speed Sensors, to determine if any wheel is begin-
ning to lock. When a front wheel locking tendency is
detected, the (CAB) will isolate the master cylinder
from the wheel brakes. This is done by activating the
Isolation Valves. The (CAB) then commands the ap-
propriate Build/Decay valves to modulate brake fluid
pressure in some or all of the hydraulic circuits. The
(CAB) continues to control pressure in individual hy-
draulic 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 Anti-Lock Warning
Lamp and disable the ABS braking system. The nor-
mal Non ABS braking system will remain opera-
tional. The (CAB) contains a self-diagnostic program
which will turn on the Amber Anti-Lock 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 automatically cleared from the memory after (50)
ignition switch on/off cycles.
CONTROLLER ANTI-LOCK 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 ANTI-LOCK BRAKE (OUTPUTS)
²6 modulator valves, 4 Build/Decay and 2 isolation
valves.
² Anti-Lock warning lamp.
² System relay actuation.
² Diagnostic communication.
² Pump motor relay actuation
Fig. 6 Tone Wheel (Typical)
Fig. 7 Location Controller Anti-Lock Brake (CAB)
Ä ANTI-LOCK 6 BRAKE SYSTEM 5 - 119

(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

VISUAL MESSAGES
Following are the visual messages and the condi-
tions under which, the messages will be given:
² Keys in ignition
² Exterior lamps on
These messages will appear if the conditions are
present and the driver's door is open while the igni-
tion switch is in the OFF, LOCK, or ACC positions.
A tone will sound until the condition is corrected or
the door is closed.
² Passenger door ajar
² Driver door ajar
² Trunk ajar
² Park brake engaged
² Right rear door ajar
² Left rear door ajar
These messages will appear if a condition is de-
tected after the vehicle is in motion. When the con-
dition is corrected, a short tone will sound to
acknowledge the action. LOW OIL PRESSURE
If this message is displayed while the vehicle is at
cruising speeds, immediate attention is required. If
this message appears at idle speed, increase the idle
speed and the message should go off. If the message
remains on, immediate attention is required. ENGINE TEMP CRITICAL
This message appears when a sensor has determined
that the engine coolant is overheating. If this message
comes on and stays on, immediate action is required.
COOLANT LEVEL LOW
LOW FUEL LEVEL
LOW BRAKE FLUID
WASHER FLUID LOW
These messages will appear if a continuous warn-
ing condition is detected while the engine is running.
Inspection is required. To clear this message from
the display, after the condition is corrected, the igni-
tion switch must be turned OFF. CHECK TRANS
This message will appear if a continuous warning
condition is detected while the engine is running. Im-
mediate attention is recommended. To clear this mes-
sage from the display, after the condition has been
corrected, the ignition switch must be turned OFF. VOLTAGE IMPROPER
This message will appear if a continuous warning
condition is detected. Immediate attention is re-
quired. To clear this message from the display, after
the condition has been corrected, the ignition switch
must be turned OFF. TURN SIGNAL ON
This message will appear if the turn signal is left
on while vehicle speed is over 15 mph and the vehi-
cle has traveled over one-half mile. FASTEN SEAT BELTS An intermittent chime tone will sound for several
seconds if the seat belt is not fastened. CHK ENGINE OIL LEVEL
If this message is delivered, a check of the engine
oil dipstick is suggested. To clear this message, after
the condition is corrected, the ignition switch must
be turned OFF. HEADLAMP OUT
BRAKE LAMP OUT
TAIL LAMP OUT
These conditions are monitored only when the lamps
are on. The message will remain, even after the lamp is
replaced, until the lamp is turned on and operates.
SERVICE REMINDER
The maintenance reminder statement is programmed
to provide general information only. Refer to Group 0,
Lubrication & Maintenance for specific vehicle require-
ments.
The service reminder message is displayed at 7,500
miles or 12 months intervals, which ever comes first. MONITORED SYSTEMS OK
If there is no warning condition to report, the mes-
sage Monitored Systems OK is displayed (Fig. 2).
AUTOMATIC CALIBRATION SET PROCEDURE
The engine compartment node will continuously
and automatically recalibrate the compass under nor-
mal driving conditions. As long as the vehicle is
turning, the engine compartment node will record
new compass data. This new data will be used to
recalibrate the compass at a rate of at least once per
full (360 degree) turn of the vehicle. Automatic cali-
bration does not require operator interface.
MANUAL CALIBRATION SET PROCEDURE
Manual compass calibration has been replaced by
automatic calibration set procedure. The manual cal-
ibration set procedure is available, but no longer
serves any useful purpose.
EVIC SELF CHECK DIAGNOSTICS
Ignition switch ON, the EVIC not displaying any
message, may imply a system failure and not an
EVIC failure. Turn the ignition OFF, close all vehi-
cle doors and wait at least 60 seconds before begin-
ning test. Turn ignition switch to the ON position.
Pressing the TEMP, FUEL and INFO buttons at the
same time shall provide the visual message MOD-
ULE SELF CHECK for two seconds. Following at
two second interval there will be messages:
² E2-0 SELF CHECK
² E3-0 SELF CHECK
² END OF SELF CHECK
Showing the microcomputer is working properly.
When the self check mode and message shows:
² E2-1
² E3-2
This would show a fault exists in the EVIC's micro-
computer and the EVIC should be replaced (Fig. 3).
8C - 8 OVERHEAD CONSOLE Ä

VISUAL MESSAGES
Following are the visual messages and the condi-
tions under which, the messages will be given:
² Keys in ignition
² Exterior lamps on
These messages will appear if the conditions are
present and the driver's door is open while the igni-
tion switch is in the OFF, LOCK, or ACC positions.
A tone will sound until the condition is corrected or
the door is closed.
² Passenger door ajar
² Driver door ajar
² Trunk ajar
² Park brake engaged
² Right rear door ajar
² Left rear door ajar
These messages will appear if a condition is de-
tected after the vehicle is in motion. When the con-
dition is corrected, a short tone will sound to
acknowledge the action. LOW OIL PRESSURE
If this message is displayed while the vehicle is at
cruising speeds, immediate attention is required. If
this message appears at idle speed, increase the idle
speed and the message should go off. If the message
remains on, immediate attention is required. ENGINE TEMP CRITICAL
This message appears when a sensor has deter-
mined that the engine coolant is overheating. If this
message comes on and stays on, immediate action is
required. COOLANT LEVEL LOW
LOW FUEL LEVEL
LOW BRAKE FLUID WASHER FLUID LOW
These messages will appear if a continuous warn-
ing condition is detected while the engine is running.
Inspection is required. To clear this message from
the display, after the condition is corrected, the igni-
tion switch must be turned OFF. CHECK TRANS
This message will appear if a continuous warning
condition is detected while the engine is running. Im-
mediate attention is recommended. To clear this mes-
sage from the display, after the condition has been
corrected, the ignition switch must be turned OFF. VOLTAGE IMPROPER
This message will appear if a continuous warning
condition is detected. Immediate attention is re-
quired. To clear this message from the display, after
the condition has been corrected, the ignition switch
must be turned OFF. TURN SIGNAL ON
This message will appear if the turn signal is left
on while vehicle speed is over 15 mph and the vehi-
cle has traveled over one-half mile. FASTEN SEAT BELTS
An intermittent chime tone will sound for several
seconds if the seat belt is not fastened. CHK ENGINE OIL LEVEL
If this message is delivered, a check of the engine
oil dipstick is suggested. To clear this message, after
the condition is corrected, the ignition switch must
be turned OFF. HEADLAMP OUT
BRAKE LAMP OUT
TAIL LAMP OUT
These conditions are monitored only when the
lamps are on. The message will remain, even after
the lamp is replaced, until the lamp is turned on and
operates. SERVICE REMINDER
The maintenance reminder statement is pro-
grammed to provide general information only. Refer
to Group 0, Lubrication & Maintenance for specific
vehicle requirements. The service reminder message is displayed at 7,500
miles or 12 months intervals, which ever comes first. MONITORED SYSTEMS OK
If there is no warning condition to report, the mes-
sage Monitored Systems OK is displayed (Fig. 3).
ENGINE COMPARTMENT NODE (ECN)
The Engine Compartment Node is a microcomputer
controlled unit which, informs the Electronic Vehicle
Information Center (EVIC) via the CCD bus of:
² Outside temperature
² Compass direction
and the following warning messages:
² Low Brake Fluid
² Low Coolant Level
² Low Engine Oil Level
Fig. 3 EVIC Messages and Sensors
Ä OVERHEAD CONSOLE 8C - 15

The coil's low primary resistance allows the PCM to
fully charge the coil for each firing.
COOLANT TEMPERATURE SENSOR
On 2.2L Turbo III engines, the coolant temperature
sensor is installed into the thermostat housing (Fig. 30).
On 3.3L and 3.8L engines, the coolant temperature sensor
is located next to the thermostat housing (Fig. 31).
The coolant temperature sensor provides an input
voltage to the powertrain control module (PCM). The
sensor is a variable resistance (thermistor) with a
range of -40ÉC to 130ÉC (-40ÉF to 265ÉF). As coolant
temperature varies, the sensor resistance changes,
resulting in a different input voltage to the PCM.
The PCM contains different spark advance schedules
for cold and warm engine operation. The schedules reduce
engine emission and improve driveability.
The PCM demands slightly richer air-fuel mixtures
and higher idle speeds until the engine reaches normal
operating temperature. The coolant sensor input is also used for cooling
fan control.
KNOCK SENSORÐTURBO III ENGINE
Turbo III engines use a knock sensor. The sensor gen-
erates a signal when spark detonation occurs in the
combustion chambers. The sensor is mounted on the in-
take manifold behind the PCV breather (Fig. 32). The
sensor provides input voltage used by the powertrain
control module (PCM) to modify spark advance and
boost schedules in order to eliminate detonation.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
The MAP sensor reacts to absolute pressure in the
intake manifold and provides an input voltage to the
powertrain control module (PCM). As engine load
changes, manifold pressure varies. The changes in
engine load cause the MAP output voltage to change.
The change in MAP sensor output voltage results in
a different input voltage to the PCM.
The input voltage level supplies the PCM with infor-
mation relating to ambient barometric pressure during
engine start-up (cranking) and engine load while its op-
erating. The PCM uses this input along with inputs
from other sensors to adjust air-fuel mixture.
On Turbo III engines, the MAP sensor is mounted
to the front right fender (Fig. 33) On 3.3L and 3.8L
engines, the MAP sensor (Fig. 34) is mounted to the
side of the intake manifold, below the positive crank-
case ventilation (PCV) valve. The sensor is connected
to the PCM electrically.
AUTO SHUTDOWN (ASD) RELAY AND FUEL PUMP
RELAY
The powertrain control module (PCM) operates the
auto shutdown (ASD) relay and fuel pump relay
through one ground path. The PCM operates the re-
lays by switching the ground path on and off. Both
relays turn on and off at the same time.
Fig. 32 Knock SensorÐTurbo III Engine
Fig. 30 Coolant Temperature SensorÐTurbo III En- gines
Fig. 31 Coolant Temperature SensorÐ3.3L and 3.8LEngines
8D - 32 IGNITION SYSTEMS Ä

The ASD relay connects battery voltage to the fuel
injector and ignition coil. The fuel pump relay con-
nects battery voltage to the fuel pump and oxygen
sensor heating element. The PCM turns the ground path off when the igni-
tion switch is in the Off position. Both relays are off.
When the ignition switch is in the On or Crank po-
sition, the PCM monitors the camshaft position sen-
sor and crankshaft position sensor signals. From
these inputs, the PCM determines engine speed and
ignition timing (coil dwell). If the PCM does not re-
ceive a camshaft position sensor signal when the ig-
nition switch is in the Run position, it will de-
energize both relays. When the relays are de-
energized, battery voltage is not supplied to the fuel
injector, ignition coil, fuel pump and oxygen sensor
heating element. On AC, AG, AJ and AY models, the ASD relay and
fuel pump relay are located in the power distribution
center (Fig. 35, 36, 37, or 38). On AA and AP models, the ASD relay and fuel
pump relay are mounted on the drivers side fender
well, next to the strut tower (Fig. 39).
Fig. 33 MAP SensorÐTurbo III Engine
Fig. 34 Map SensorÐ3.3L and 3.8L Engines
Fig. 35 Power Distribution Center (PDC) (AC Body)
Fig. 36 Relay Identification (AC Body)
Fig. 37 Power Distribution Center (PDC) (AG and AJ Body)
Ä IGNITION SYSTEMS 8D - 33