Operation; Removal - Chrysler PT Cruiser Service & Repair Manual

PT
REAR WHEEL SPEED SENSOR (Continued)
The rear wheel speed sensors are mounted through
the disc brake adapter (Fig. 9) (Fig. 10). The rear
tone wheels are mounted to and rotate with the hub
and bearing assemblies.
The WSS air gaps are not adjustable. The initial
factory WSS air gap specification can be found in
SPECIFICATIONS. Each WSS is serviced individu-
ally. The tone wheels are serviced as an assembly
with the hub and bearing assemblies.
Fig. 9 Left Rear Wheel Speed Sensor
1 - LEFT REAR WHEEL SPEED SENSOR
2 - SHOCK ABSORBER
Fig. 10 Right Rear Wheel Speed Sensor
1 - SHOCK ABSORBER
2 - RIGHT REAR WHEEL SPEED SENSOR

OPERATION

The CAB sends 12 volts to power an Integrated
Circuit (IC) in the sensor. The IC supplies a constant
7 mA power supply to the CAB. The relationship of
the tooth on the tone wheel to the permanent magnet
in the sensor, signals the IC to enable a second 7 mA
power supply. The output of the sensor, sent to the
CAB, is a DC voltage signal with changing voltage
and current levels. The ground for the IC and the
current sense circuit is provided by the CAB.
When a valley of the tone wheel is aligned with the
sensor, the voltage signal is approximately 0.8 volts
and a constant 7 mA current is sent to the CAB. As
the tone wheel rotates, the tooth shifts the magnetic
field and the IC enables a second 7 mA current
source. The CAB senses a voltage signal of approxi-
mately 1.6 volts and 14 mA. The CAB measures the
amperage of the digital signal for each wheel. The
resulting signal is interpreted by the ABS CAB as
the wheel speed.

REMOVAL

NOTE: Before proceeding, (Refer to 5 - BRAKES -
WARNING)(Refer to 5 - BRAKES - CAUTION).
(1) Raise the vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(2) Remove the tire and wheel assembly from the
vehicle.
(3) Disconnect the wheel speed sensor cable con-
nector from the vehicle wiring harness (Fig. 11).
Remove the clip attaching wheel speed sensor cable
connector to the vehicle's body.
(4) Disconnect the wheel speed sensor cable rout-
ing clips running along the brake tube, brake hose
and axle trailing arm.
CAUTION: When removing a wheel speed sensor
from the rear disc brake adapter, do not use pliers
on the sensor head. This may damage the sensor
head. If the sensor has seized, use a hammer and a
punch to tap the edge of the sensor head ear, rock-
ing the sensor side-to-side until free.
(5) Remove the bolt attaching the wheel speed sen-
sor to the rear disc brake adapter (Fig. 12), then
carefully remove the sensor head from the rear disc
brake adapter and vehicle.
BRAKES - ABS 5 - 81