Dodge Dakota (R1). Manual - part 240

using a high impedance multi-meter or the DRB
tester as described in this section. Power should
never be removed or applied to any control module
with the ignition in the ON position. Before removing
or connecting battery cables, fuses, or connectors,
always turn the ignition to the OFF position.

CAUTION: Use only factory wiring harnesses. Do
not cut or splice wiring to the brake circuits. The
addition of after-market electrical equipment (car
phone, radar detector, citizen band radio, trailer
lighting, trailer brakes, ect.) on a vehicle equipped
with antilock brakes may affect the function of the
antilock brake system.

STANDARD PROCEDURES - BLEEDING ABS
BRAKE SYSTEM

ABS system bleeding requires conventional bleed-

ing methods plus use of the DRB scan tool. The pro-

cedure involves performing a base brake bleeding,
followed by use of the scan tool to cycle and bleed the
HCU pump and solenoids. A second base brake bleed-
ing procedure is then required to remove any air
remaining in the system.

(1) Perform base brake bleeding. (Refer to 5 -

BRAKES - STANDARD PROCEDURE).

(2) Connect scan tool to the Data Link Connector.
(3) Select ANTILOCK BRAKES, followed by MIS-

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

(4) Perform base brake bleeding a second time.

(Refer to 5 - BRAKES - STANDARD PROCEDURE).

(5) Top off master cylinder fluid level and verify

proper brake operation before moving vehicle.

SPECIFICATIONS

TORQUE CHART

TORQUE SPECIFICATIONS

DESCRIPTION

N·m

Ft. Lbs.

In. Lbs.

ABS Assembly

Bracket bolts

14-15

10-12

—

ABS Assembly

Mounting Nuts

—

102

ABS Assembly

CAB Screws

4-4.7

—

36-42

ABS Assembly

Brake Line Fittings

—

170

Controller

Mounting Screws

—

RWAL Valve

Mounting Bolt

20-27

15-20

—

RWAL Valve

Brake Line Fittings

—

170

Wheel Speed Sensor

Mounting Bolt

—

200

Wheel Speed Sensors

Front Sensor Bolt

—

190

Wheel Speed Sensors

Rear Sensor Bolt

22.5

—

195

5 - 36

BRAKES - ABS

BRAKES - ABS (Continued)

FRONT WHEEL SPEED
SENSOR

DESCRIPTION

The ABS brake system uses 3 wheel speed sensors.

A sensor is mounted to each front steering knuckles.
The third sensor is mounted on top of the rear axle
differential housing.

OPERATION

The WSS consists of a magnet surrounded by

windings from a single strand of wire. The sensor
sends a small AC signal to the CAB. This signal is
generated by magnetic induction. The magnetic
induction is created when a toothed sensor ring
(exciter ring or tone wheel) passes the stationary
magnetic WSS.

When the ring gear is rotated, the exciter ring

passes the tip of the WSS. As the exciter ring tooth
approaches the tip of the WSS, the magnetic lines of
force expand, causing the magnetic field to cut across
the sensor’s windings. This, in turn causes current to
flow through the WSS circuit (Fig. 2) in one direc-
tion. When the exciter ring tooth moves away from
the sensor tip, the magnetic lines of force collapse
cutting the winding in the opposite direction. This
causes the current to flow in the opposite direction.
Every time a tooth of the exciter ring passes the tip
of the WSS, an AC signal is generated. Each AC sig-
nal (positive to negative signal or sinewave) is inter-
preted by the CAB. It then compares the frequency of
the sinewave to a time value to calculate vehicle
speed. The CAB continues to monitor the frequency
to determine a deceleration rate that would indicate
a possible wheel-locking tendency.

The signal strength of any magnetic induction sen-

sor is directly affected by:

• Magnetic field strength; the stronger the mag-

netic field, the stronger the signal

• Number of windings in the sensor; more wind-

ings provide a stronger signal

• Exciter ring speed; the faster the exciter ring/

tone wheel rotates, the stronger the signal will be

• Distance between the exciter ring teeth and

WSS; the closer the WSS is to the exciter ring/tone
wheel, the stronger the signal will be

The rear WSS is not adjustable. A clearance speci-

fication has been established for manufacturing toler-
ances.

the

clearance

not

within

these

specifications, then either the WSS or other compo-
nents may be damaged. The clearance between the
WSS and the exciter ring is 0.005 – 0.050 in.

The assembly plant performs a “Rolls Test” on

every vehicle that leaves the assembly plant. One of
the test performed is a test of the WSS. To properly

test the sensor, the assembly plant connects test
equipment to the Data Link Connector (DLC). This
connector is located to the right of the steering col-
umn and attached to the lower portion of the instru-
ment panel (Fig. 3). The rolls test terminal is spliced
to the WSS circuit. The vehicle is then driven on a
set of rollers and the WSS output is monitored for
proper operation.

Fig. 2 Operation of the Wheel Speed Sensor

1 - MAGNETIC CORE
2 - CAB
3 - AIR GAP
4 - EXCITER RING
5 - COIL

Fig. 3 Data Link Connector - Typical

1 - 16–WAY DATA LINK CONNECTOR

BRAKES - ABS

5 - 37

REMOVAL - 4X2

CAUTION: Special bolts are used to attach the front
sensor. The bolts have a special shoulder, thread
length and surface treatment. If the original bolts
must be replaced, use only factory replacement
part. Do not use substitute bolts under any circum-
stances.

(1) Raise and support vehicle.
(2) Remove bolt attaching sensor to the steering

knuckle (Fig. 4).

(3) Remove clamps securing sensor wire to control

arm and inner fender panel.

(4) In engine compartment, disconnect sensor wire

from harness and remove sensor.

REMOVAL - 4X4

CAUTION: Special bolts are used to attach the front
sensor. The bolts have a special shoulder, thread
length and surface treatment. If the original bolts
must be replaced, use only factory replacement
bolts. Do not use substitute bolt under any circum-
stances.

(1) Raise and support vehicle.
(2) Remove wheel and tire assembly.
(3) Remove brake caliper and rotor. (Refer to 5 -

BRAKES/HYDRAULIC/MECHANICAL/ROTORS

REMOVAL).

(4) Remove bolts attaching sensor to hub/bearing

(Fig. 5).

(5) Remove clamps securing sensor wire to control

arm and inner fender panel.

(6) In engine compartment, disconnect sensor wire

and remove sensor.

INSTALLATION - 4X2

(1) Position sensor in the knuckle and install sen-

sor attaching bolts. Tighten bolts to 21 N·m (190 in.
lbs.).

(2) Secure sensor wire retaining clamps to control

arm and fender panel.

(3) In engine compartment, connect sensor wire to

harness connector. Make sure wire is routed away
from hot or rotating underhood components.

(4) Turn steering wheel back and forth to verify

that wire is clear of steering and suspension compo-
nents.

(5) Remove supports and lower vehicle.

INSTALLATION - 4X4

CAUTION: Special bolts are used to attach the front
sensor. The bolts have a special shoulder, thread
length and surface treatment. If the original bolts
must be replaced, use only factory replacement
bolts. Do not use substitute bolt under any circum-
stances.

(1) Guide sensor wire around upper control arm.

Fig. 4 Front Wheel Speed Sensor - 4x2

1 - WHEEL SPEED SENSOR
2 - KNUCKLE
3 - MOUNTING BOLT

Fig. 5 Front Wheel Speed Sensor - 4x4

1 - WHEEL SPEED SENSOR
2 - HUB/BEARING
3 - MOUNTING BOLTS

5 - 38

BRAKES - ABS

FRONT WHEEL SPEED SENSOR (Continued)

(2) Position sensor on hub/bearing and install

attaching bolts. Tighten bolt to 18-25 N·m (160-220
in. lbs.).

(3) Secure sensor wire retaining clamps to control

arm and fender panel with original hardware.

(4) In engine compartment, connect sensor wire to

harness connector. Insure wire is routed away from
hot or rotating underhood components.

(5) Install brake rotor and caliper. (Refer to 5 -

BRAKES/HYDRAULIC/MECHANICAL/ROTORS

INSTALLATION).

(6) Install wheel and tire assembly. (Refer to 22 -

TIRES/WHEELS/WHEELS - STANDARD PROCE-
DURE).

(7) Turn steering wheel back and forth to verify

that wire is clear of steering and suspension compo-
nents.

(8) Remove supports and lower vehicle.

REAR WHEEL SPEED SENSOR

REMOVAL

(1) Raise vehicle on hoist.
(2) Remove brake line mounting nut and remove

the brake line from the sensor stud.

(3) Remove mounting stud from the sensor and

shield (Fig. 7).

(4) Remove sensor and shield from differential

housing.

(5) Disconnect sensor wire harness and remove

sensor.

INSTALLATION

(1) Connect harness to sensor. Be sure seal is

securely in place between sensor and wiring
connector.

(2) Install O-ring on sensor (if removed).
(3) Insert sensor in differential housing.
(4) Install sensor shield.
(5) Install the sensor mounting stud and tighten to

24 N·m (200 in. lbs.).

(6) Install the brake line on the sensor stud and

install the nut.

(7) Lower vehicle.

TONE WHEEL

DESCRIPTION

The rear Wheel Speed Sensor (WSS) is mounted in

the rear differential housing (Fig. 8).

The exciter ring is press fitted onto the differential

carrier next to the final drive ring gear (Fig. 9).

REMOVAL- EXCITER RING

The exciter ring is mounted on the differential

case. If the ring is damaged (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/REAR AXLE - 8 1/4/PINION
GEAR/RING GEAR/TONE RING - REMOVAL).

REMOVAL - TONE WHEEL

The tone wheel for the front speed sensor is located

on the hub/bearing on 2-wheel drive models (Fig. 10).
On 4-wheel drive models, the tone wheel is located in
the hub/bearing housing.

The tone wheel is not a serviceable component. To

replace the tone wheel the hub/bearing must be

Fig. 6 Front Wheel Speed Sensor - 4x2

1 - WHEEL SPEED SENSOR
2 - KNUCKLE
3 - MOUNTING BOLT

Fig. 7 Rear Speed Sensor Mounting

1 - DIFFERENTIAL HOUSING
2 - WHEEL SPEED SENSOR

BRAKES - ABS

5 - 39

FRONT WHEEL SPEED SENSOR (Continued)

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