Chrysler 1997 Stratus Convertible RHD Service Manual page 170

SYSTEM RELAY AND PUMP/ MOTOR RELAY BOX SYSTEM RELAY AND PUMP/MO- TOR RELAY BOX 10 WAY CON-
5 - 68 BRAKES
DESCRIPTION AND OPERATION (Continued)
Fig. 2 System Relay And Pump/Motor Relay Box
The system relay is energized by the CAB shortly
after the ignition switch is turned on.
When energized by the CAB, the system relay
turns off the ABS warning lamp and provides 12
volts to the CAB. This voltage can then be used by
the CAB to energize the decay solenoids during ABS
braking. When energized, the system relay also pro-
vides the pump/motor relay coil with 12 volts. The
ground path to the pump/motor relay is completed by
the CAB during ABS braking.
Conversely, when the system relay is de-energized,
the ABS warning lamp is illuminated, voltage to the
decay solenoids is cut off, and the pump/motor relay
is prevented from energizing. Typically, the system
relay is de-energized by the controller when a fault is
detected that requires turning ABS off.
PROPORTIONING VALVE
Two Proportioning Valves are used in the Allied
Signal ABX-4 ABS system, one for each rear wheel
brake hydraulic circuit. The proportioning valves
function the same as in a standard brake system.
The proportioning valves (Fig. 3) are located on the
front of the HCU. The proportioning valve can be
identified by the bar code label and stamp on the
proportioning valve (Fig. 3). Be sure replacement pro-
portioning valve has the same stamp as the propor-
tioning valve being replaced.
WHEEL SPEED SENSORS
One Wheel Speed Sensor (WSS) is located at each
wheel (Fig. 4) and (Fig. 5), and sends a small AC sig-
nal to the control module CAB. This signal is gener-
ated by magnetic induction created when a toothed
sensor ring (tone wheel) (Fig. 4) and (Fig. 5) passes
the stationary magnetic wheel speed sensor. The
CAB converts the AC signal generated at each wheel
into a digital signal. If a wheel locking tendency is
detected by the CAB, it will then modulate hydraulic
NECTOR 6–WAY NECTOR CON- WHEEL SPEED SEN- BAR BRAKE SUPPORT TO REAR BRAKE LINE STEERING WHEEL TONE WHEEL CODE PLATE KNUCKLE SENSOR SPEED LABEL SOR STAMP AND TONE WHEEL
Fig. 3 Proportioning Valve Identification
pressure via the HCU to prevent the wheel(s) from
locking.
Fig. 4 Front Wheel Speed Sensor And Tone Wheel
Fig. 5 Rear Wheel Speed Sensor And Tone Wheel
With Drum Brakes
The front Wheel Speed Sensor is attached to a boss
in the steering knuckle (Fig. 4). The tone wheel is
part of the outboard constant velocity joint (Fig. 4).
The rear Wheel Speed Sensor on rear drum brake
applications is mounted to the rear brake support
ATTACHING O-RING SEAL BOLT TO MASTER CYLINDER OR HYDRAULIC CONTROL UNIT HUB/BEARING ASSEMBLY
WHEEL SPEED SENSOR DRIVESHAFT
CABLE
JX