The 4ABS ensures directional skid and control dur-
ing hard braking.
This ABS uses a 4-sensor system that controls all
four wheels independently of each other.

• EBD

control can obtain ideal rear wheel brake

force.

• The magnetic encoder for wheel speed detection

has been installed instead of the rotor as the
wheel speed sensor.

• For wiring harness saving and secure data com-

munication, CAN

bus has been adopted as a

tool of communication with another ECU.

• Fail-safe function which ensures that safety is

maintained.

• Diagnostic function which provides improved ser-

viceability.

NOTE:

•

: EBD (Electronic Brake-force Distribution)

•

: For more details about CAN (Controller Area

Network), refer to GROUP 54C

P.54C-2

Specifications

CONSTRUCTION DIAGRAM

Item

Specification

ABS control type

4 sensors

Wheel speed sensor

Magnetic encoder

Front

86 (N pole: 43, S pole: 43)

Rear

86 (N pole: 43, S pole: 43)

Type

Semiconductor

CHECK

SERVICE
REQUIRED

AC901728

4, 10

SERVICE SPECIFICATIONS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-3

MAIN COMPONENTS AND FUNCTIONS

SERVICE SPECIFICATIONS

M1352000300997

Name of part

Number Outline of function

Sensor

Wheel speed sensor

Outputs the frequency signal in proportion to the rotation
speed of each wheel to ABS-ECU.

Magnetic encoder for
wheel speed detection

When the magnetic encoder for wheel speed detection (a
plate on which north and south pole sides of the magnets
are arranged alternately) rotates, the wheel speed sensor
outputs frequency pulse signal in proportion to each wheel
speed.

Stoplight switch

Outputs the signal indicating whether the brake pedal is
depressed or not to ABS-ECU.

Actuator Hydraulic unit

Drives the solenoid valve using the signal from ABS-ECU,
and controls the brake fluid pressure for each wheel.

ABS warning light

Informs the driver of the system status by illuminating,
flashing, or turning off the warning light according to the
signal from ABS-ECU.

ABS warning display

Informs the driver of the system status by illuminating or
turning off the warning light according to the signal from
ABS-ECU.

Brake warning light

Used as the warning light for the parking brake, brake fluid
level, and EBD control. Informs the driver of the system
status by illuminating or turning off the warning light
according to the signal from ABS-ECU.

Brake warning display

Data link connector

Outputs the diagnostic trouble code and establishes the
communication with scan tool.

ABS-ECU

Controls actuators (described above) based on the signals
coming from each sensor.
Controls the self-diagnosis and fail-safe functions.
Controls the diagnosis function (scan tool compatible).

Item

Standard value

Wheel speed sensor current mA

5.9

− 8.4 or 11.8 − 16.8

Wheel speed sensor insulation resistance M

5 or more

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-4

ABS DIAGNOSIS

INTRODUCTION

M1352012500512

The anti-lock brake system (ABS) operates differ-
ently from conventional brake systems. These differ-
ences include sounds, sensations, and vehicle
performance that owners and service technicians
who are not familiar with ABS may not be used to.

Some operational characteristics may seem to be
malfunctions, but they are simply signs of normal
ABS operation. When diagnosing the ABS system,
keep these operational characteristics in mind.
Inform the owner of the kind of performance charac-
teristics to expect from an ABS-equipped vehicle.

ABS DIAGNOSTIC TROUBLE CODE DETECTION CONDITIONS

ABS diagnostic trouble codes (ABS DTCs) are set
under different conditions, depending on the mal-
function detected. Most ABS DTCs will only be set
during vehicle operation. Some ABS DTCs will also
be set during the ABS self-check immediately after
the engine is started.

When you check if an ABS DTC will be displayed
again after the DTC has been erased, you should
duplicate the ABS DTC set conditions. Depending on
the detection timing and set conditions for the spe-
cific ABS DTC, you must either drive the vehicle or
turn the engine off and restart it. To set the proper
conditions for that DTC again, refer to "ABS DTC
SET CONDITIONS" for each ABS DTC that you are
trying to reset.

ABS DIAGNOSTIC TROUBLESHOOTING STRATEGY

M1352011101020

Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure that you
have exhausted most of the possible ways to find an
ABS fault.
1. Gather information about the problem from the

customer.

2. Verify that the condition described by the

customer exists.

3. Check the vehicle for any ABS DTC.
4. If you cannot verify the condition and there are no

ABS DTCs, the malfunction is intermittent. Refer
to GROUP 00, How to use
Troubleshooting/Inspection Service Points

− How

to Cope with Intermittent Malfunctions

P.00-15

5. If you can verify the condition but there are no

ABS DTCs, or the system cannot communicate
with the scan tool, check that the basic brake
system is operating properly.

• If the basic brake system is not operating prop-

erly, refer to the GROUP 35A, Basic Brake Sys-
tem Diagnosis