Lexus ES300 (2002 year). Manual - part 296

F41239

2

1

05-312

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

465

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

2

INSPECT FRONT SPEED SENSOR

(a)

Remove the fender liner.

(b)

Disconnect the speed sensor connector.

(c)

Measure resistance between terminals 1 and 2 of the
speed sensor connector.
OK: 1.4 - 1.8 k

Ω 

at 20



C

(d)

Measure resistance between each of terminals 1 and 2 of
speed sensor connector and body ground.
OK: 1 M

Ω

 or higher

A

OK

B

NG (Right front speed sensor)

C

NG (Left front speed sensor)

B

REPLACE SPEED SENSOR FRONT RH

C

REPLACE SPEED SENSOR FRONT LH

NOTICE:
Check the speed sensor signal last (See page 

05-288

).

A

3

CHECK HARNESS AND CONNECTOR(FRONT SPEED SENSOR-SKID CONTROL
ECU ASSY)

(a)

Check for open and short circuit in harness and connector between each speed sensor and skid con-
trol ECU connector (See page 

01-31

).

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

W04200

Normal Signal Waveform

1 V / Division

2 m/s / Division

GND

BR3795

OK

NG

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-313

466

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

4

CHECK SPEED SENSOR AND SENSOR ROTOR SERRATIONS

(REFERENCE) INSPECTION USING OSCILLOSCOPE
(a)

Remove the skid control ECU with connectors still con-
nected.

(b)

Connect the oscilloscope to the terminals FR+ - FR- and
FL+ - FL- of the skid control ECU.

(c)

Drive the vehicle at about 30 km/h (19 mph), and check
the signal waveform.

HINT:

As the vehicle speed (wheel revolution speed) increases,
a cycle of the waveform becomes shorter and the fluctua-
tion in the output voltage becomes greater.

When noise is identified in the waveform on the oscillo-
scope, error signals are generated due to the speed sen-
sor rotor’s scratches, looseness or foreign matter depos-
ited on it.

OK

CHECK AND REPLACE SKID CONTROL ECU
ASSY

NG

5

CHECK FRONT SPEED SENSOR INSTALLATION

(a)

Check the speed sensor installation.
OK:
The installation bolt is tightened properly and there is
no clearance between the sensor and front steering
knuckle.
Torque: 8.0 N

⋅

m (82 kgf

⋅

cm, 71 in.

⋅

lbf)

A

OK

B

NG (Right front speed sensor)

C

NG (Left front speed sensor)

B

REPLACE SPEED SENSOR FRONT RH

C

REPLACE SPEED SENSOR FRONT LH

NOTICE:
Check the speed sensor signal last (See page 

05-288

).

A

05-314

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

467

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

6

CHECK SPEED SENSOR ROTOR AND SENSOR TIP

NG

CLEAN OR REPLACE SPEED SENSOR AND
SENSOR ROTOR SERRATIONS

NOTICE:
Check the speed sensor signal last (See page 

05-288

).

OK

CHECK AND REPLACE SKID CONTROL ECU ASSY

055XH-02

F16280

USA:

CANADA:

C52361

Tc

CG

-

DIAGNOSTICS

ABS WITH EBD SYSTEM

05-239

392

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

PRE-CHECK

1.

DIAGNOSIS SYSTEM

(a)

Release the parking brake pedal.

(b)

Check the warning light.
When the ignition switch is turned ON, check that the ABS
warning light and BRAKE warning light turns on for 3 sec.

HINT:

When the parking brake is applied or the level of the brake
fluid is low, the BRAKE warning light is lit.

If the indicator check result is not normal, proceed to trou-
bleshooting for the ABS warning light circuit (See page

05-275

 or 

05-277

) or BRAKE warning light circuit (See

page 

05-278

).

(c)

In case of not using hand-held tester:
Check the DTC.
(1)

Using SST, connect terminals Tc and CG of DLC3.

SST

09843-18040

(2)

Turn the ignition switch ON.

(3)

Read the DTC from the ABS warning light on the
combination meter.

HINT:

If a code does not appear, inspect the diagnostic circuit
or ABS warning light circuit (See page 

05- 275

 or

05-277

).