Chrysler Concorde 1993, Руководство по обслуживанию, Страница: 177 / 820

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during Anti-Lock stop and traction control opera-
tion.
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Monitor the system for proper operation.
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Provide communication to the DRB II while in di-
agnostic mode.
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Store diagnostic information in non-volatile mem-
ory.
The (CAB) continuously monitors the speed of each
wheel. When a wheel locking tendency is detected,
the (CAB) will command the appropriate valve to
modulate brake fluid pressure in its hydraulic cir-
cuit. In order to increase pressure at the wheel brake
again, the inlet valve in the (HCU) is opened to the
wheel brake which causes the pedal to drop. During
an anti-lock stop, the brake pedal position is main-
tained within a controlled region by the Pedal Travel
Sensor (PTS) and the pump/motor. The PTS has
seven resistance steps. Once an anti-lock control cy-
cle has been initiated, the (CAB) will activate the
pump/motor when the PTS level increases one step.
The (CAB) will again turn off the pump/motor once
the original position is reached again. The (CAB)
continues to control pressure in individual hydraulic
circuits until a wheel locking tendency is no longer
present.
On traction control equipped vehicles ONLY, the
(CAB) is continuously monitoring wheel speed, it can
also detect wheel spin (traction loss) conditions. If
the (CAB) detects drive wheel spin and the brakes
are not applied it will enter the Traction Control
mode. When a wheel spin condition is detected the
(CAB) will close the normally open Traction Control
Valves. When the Traction Control valves are closed
the master cylinder primary and secondary cham-
bers, and the rear brake channels are isolated from
the drive wheel brake channels. The pump motor is
started to supply fluid volume/pressure to the drive
wheel brake channels. The pump runs continuously
during traction control operation. The inlet and out-
let valves are opened and closed to modulate the hy-
draulic pressure in the appropriate brake channel.
By cycling the inlet and outlet valves, the (CAB) can
control wheel spin by applying the brakes on the
wheel that has lost traction.
The Anti-Lock Brake and Traction Control Systems
are constantly monitored by the (CAB) for proper op-
eration. If the (CAB) detects a fault, it can disable
the Anti-Lock and Traction Control function and
turn on the warning lamps. If the Anti-Lock function
is disabled, the system will revert to standard base
brake system operation.
The (CAB) Inputs include the following:
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Four Wheel Speed Sensors
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Stop Lamp Switch
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Pedal Travel Sensor
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Ignition Switch
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Main Relay Voltage
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Pump/Motor Sensor Signal
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Diagnostic Communication (C2D)
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Fluid Level Switch #2
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Traction Control Switch
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Pressure Switch
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ABS Warning Lamp Voltage
The (CAB) Outputs include the following:
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Eight Valve/Solenoid Drivers (Ten with Traction
Control)
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Main Relay Actuation
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Pump/Motor Relay Actuation
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Anti-lock Light Actuation
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Brake Warning Light Actuation
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Traction Control Warning Lamp Actuation
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Traction Control Function Lamp Actuation
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Diagnostic Communication (C2D)
DIAGNOSTIC CONNECTOR
On the L.H. platform, the Teves Mark IV diagnos-
tic connector is located under the lower instrument
panel to the right side of the steering column. The
diagnostics connector is a blue 6 way connector see
(Fig. 7).
ANTI-LOCK SYSTEM RELAYS AND WARNING
LAMPS
SYSTEM RELAY
The System Relay (Fig. 8) is attached to the out-
side of the Power Distribution Center. The System
Relay has two functions. First, when the relay is en-
ergized, it supplies power to the solenoid valves in
the Valve Block Assembly and the pump/motor relay
coil. Second, when the relay is de-energized, it sup-
plies a ground to turn on the ANTI-LOCK warning
light. The System Relay is controlled by the (CAB).
The (CAB) energizes the System Relay when it re-
ceives an ignition input signal.
Fig. 7 ABS Diagnostic Connector Location
ANTI-LOCK BRAKE SYSTEM 5 - 83