Dodge Neon / Neon SRT-4. Manual - part 51

bled anytime it is suspected that the HCU has
ingested air. Under most circumstances that require
the bleeding of the brakes hydraulic system, only the
base brake hydraulic system needs to be bled.

When bleeding the ABS system, the following

bleeding sequence must be followed to insure com-
plete and adequate bleeding.

(1) Make sure all hydraulic fluid lines are installed

and properly torqued.

(2) Connect the DRBIII

t scan tool to the Data

Link Connector. The connector is located under the
lower steering column cover to the left of the steering
column.

(3) Using the DRBIII

t, check to make sure the

CAB does not have any fault codes stored. If it does,
clear them using the DRBIII

WARNING: WHEN BLEEDING THE BRAKE SYSTEM
WEAR SAFETY GLASSES. A CLEAR BLEED TUBE
MUST BE ATTACHED TO THE BLEEDER SCREWS
AND SUBMERGED IN A CLEAR CONTAINER FILLED
PART WAY WITH CLEAN BRAKE FLUID. DIRECT
THE FLOW OF BRAKE FLUID AWAY FROM YOUR-
SELF AND THE PAINTED SURFACES OF THE VEHI-
CLE. BRAKE FLUID AT HIGH PRESSURE MAY
COME OUT OF THE BLEEDER SCREWS WHEN
OPENED.

(4) Bleed the base brake system using the stan-

dard pressure or manual bleeding procedure. (Refer
to 5 - BRAKES - BASE - STANDARD PROCEDURE)

(5) Using

the

DRBIII

select

ANTILOCK

BRAKES,

followed

MISCELLANEOUS,

then

BLEED BRAKES. Follow the instructions displayed.
When the scan tool displays TEST COMPLETED,
disconnect the scan tool and proceed.

(6) Bleed the base brake system a second time.

Check brake fluid level in the reservoir periodically
to prevent emptying, causing air to enter the hydrau-
lic system.

(7) Fill the master cylinder reservoir to the full

level.

(8) Test drive the vehicle to be sure the brakes are

operating correctly and that the brake pedal does not
feel spongy.

SPECIFICATIONS

ABS FASTENER TORQUE

(Refer to 5 - BRAKES - BASE - SPECIFICATIONS

- BRAKE FASTENER TORQUE)

TONE WHEEL RUNOUT

FRONT TONE WHEEL:

Maximum Runout

0.25 mm (0.009 in.)

REAR TONE WHEEL:

Maximum Runout

0.25 mm (0.009 in.)

WHEEL SPEED SENSOR AIR GAP

DESCRIPTION

SPECIFICATION

FRONT SENSOR

0.28 – 1.42 mm

0.011 – 0.056 in.

REAR SENSOR

0.45 – 1.12 mm

0.018 – 0.044 in.

FRONT WHEEL SPEED
SENSOR

DESCRIPTION

The Mark 20e system uses two-wire wheel speed

sensors, known as active wheel speed sensors. The
sensors use an electronic principle known as magne-
toresistive to help increase performance and durabil-
ity. The sensors convert wheel speed into a small
digital signal. A wheel speed sensor is used at each
wheel. The gear (tooth) type tone wheel serves as the
trigger mechanism for each sensor. At each wheel of
the vehicle there is one wheel speed sensor and one
tone wheel.

The front wheel speed sensors are attached to

bosses in the steering knuckle (Fig. 2) (Fig. 3). The
tone wheel is an integral part of the outboard con-
stant velocity joint located in the front axle shaft.

WSS air gaps are not adjustable. The initial fac-

tory WSS air gap specification can be found in SPEC-
IFICATIONS. Each WSS is serviced individually. The
tone wheels are serviced as part of the drive shaft.

5 - 86

BRAKES - ABS

PL/SRT-4

BRAKES - ABS (Continued)

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 with this procedure,
(Refer to 5 - BRAKES - WARNING).

(1) Raise the vehicle. (Refer to LUBRICATION &

MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).

(2) Disconnect the wheel speed sensor cable con-

nector from the wiring harness on the inside of the
frame rail above the front suspension crossmember
(Fig. 4). The connector has a locking tab which that
must be pulled back before the connector release
tang can be depressed, releasing the connection.

(3) If the sensor being removed is a left front,

unclip the speed sensor cable from the brake tube on
the inside of and under the frame rail (Fig. 5).

(4) Remove the speed sensor cable grommet from

the retaining bracket attached to the brake hose on
the outside of the frame rail.

Fig. 2 Left Front Wheel Speed Sensor (Heat Shield

Not Shown)

1 - LEFT FRONT WHEEL SPEED SENSOR
2 - TONE WHEEL

Fig. 3 Right Front Wheel Speed Sensor (Heat Shield

Not Shown)

1 - RIGHT FRONT WHEEL SPEED SENSOR
2 - TONE WHEEL

Fig. 4 Wiring Harness Connector

1 - RIGHT FRONT WHEEL SPEED SENSOR CONNECTOR
2 - RIGHT FRONT DRIVESHAFT
3 - ENGINE OIL FILTER

PL/SRT-4

BRAKES - ABS

5 - 87

FRONT WHEEL SPEED SENSOR (Continued)

(5) Remove the bolt mounting the wheel speed sen-

sor head to the steering knuckle (Fig. 6).

CAUTION: When removing a wheel speed sensor
from the knuckle, do not use pliers on the sensor
head. This may damage the sensor head. If the sen-
sor has seized, use a hammer and a punch to tap
the edge of the sensor head ear, rocking the sensor
side-to-side until free.

(6) Carefully, remove the sensor head from the

steering knuckle.

(7) Remove the screw securing the wheel speed

sensor to the rear of the strut (Fig. 7). Remove the
wheel speed sensor.

INSTALLATION

CAUTION: Failure to install speed sensor cables
properly may result in contact with moving parts or
an over extension of cables causing an open cir-
cuit. Be sure that cables are installed, routed, and
clipped properly.

(1) Attach the wheel speed sensor to the strut

using the its mounting screw (Fig. 7).

(2) Install the wheel speed sensor head in the

steering knuckle (Fig. 6). Install the mounting bolt.
Tighten the mounting bolt to a torque of 12 N·m (105
in. lbs.).

(3) From the sensor bracket on the strut, loop the

sensor cable upward, then downward at the outside
of the frame rail. Install the speed sensor cable grom-
met onto the retaining bracket attached to the brake
hose on the outside of the frame rail.

(4) Loop the wheel speed sensor cable around the

bottom of the frame rail and connect it to the wiring
harness connector on the inside of the frame rail
(Fig. 4). Remember to push in the locking tab on the
connector.

(5) If the sensor being installed is the left front,

clip the speed sensor cable to the brake tube on the
inside of and under the frame rail (Fig. 5).

(6) Lower the vehicle.

Fig. 5 LEFT SENSOR ROUTING ALONG BRAKE

TUBE

1 - ABS ICU
2 - BRAKE TUBE
3 - FRAME RAIL
4 - ROUTING CLIPS
5 - WHEEL SPEED SENSOR CABLE

Fig. 6 Wheel Speed Sensor

1 - RIGHT FRONT WHEEL SPEED SENSOR
2 - TONE WHEEL

Fig. 7 Wheel Speed Sensor At Strut

1 - ABS WHEEL SPEED SENSOR ROUTING BRACKET (IF
EQUIPPED)
2 - GROUND STRAP
3 - GROUND STRAP SCREW
4 - ABS SENSOR BRACKET SCREW (IF EQUIPPED)

5 - 88

BRAKES - ABS

PL/SRT-4

FRONT WHEEL SPEED SENSOR (Continued)

(7) Road test vehicle to ensure proper operation of

the base brakes and ABS.

REAR WHEEL SPEED SENSOR

DESCRIPTION

The Mark 20e system uses two-wire wheel speed

The rear wheel speed sensors are mounted through

the disc brake adapter (Fig. 8) (Fig. 9). 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.

OPERATION

The CAB sends 12 volts to power an Integrated

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

REMOVAL

NOTE: Before proceeding with this procedure,
(Refer to 5 - BRAKES - WARNING).

(1) Raise the vehicle. (Refer to LUBRICATION &

MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).

(2) Disconnect the wheel speed sensor cable con-

nector from the vehicle wiring harness (Fig. 10).
Remove the clip attaching wheel speed sensor cable
connector to the vehicle’s body.

(3) Remove the wheel speed sensor cable routing

bracket from under rear brake flex hose mounting
bracket. Then remove the speed sensor cable from
the routing clips on the rear brake flex hose and
chassis brake tube.

(4) Remove the bolt attaching the wheel speed sen-

sor cable routing bracket to rear strut.

Fig. 8 Left Rear Wheel Speed Sensor

1 - LEFT REAR WHEEL SPEED SENSOR
2 - TENSION STRUT

Fig. 9 Right Rear Wheel Speed Sensor

1 - RIGHT REAR WHEEL SPEED SENSOR
2 - TENSION STRUT

PL/SRT-4

BRAKES - ABS

5 - 89

FRONT WHEEL SPEED SENSOR (Continued)

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