Lexus ES300 (2002 year). Manual - part 295

0529H-03

05-308

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DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

461

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

PROBLEM SYMPTOMS TABLE

If a normal code is displayed during the DTC check but the problem still occurs, check the circuits for each
problem symptom in the order given in the table below and proceed to the relevant troubleshooting page.
NOTICE:
When replacing skid control ECU, sensor or etc., turn the ignition switch OFF.

Symptom

Suspect Area

See page

ABS does not operate
BA does not operate
EBD does not operate

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. IG power source circuit and ground circuit

3. Speed sensor circuit

4. Check the ABS & Traction actuator with a hand-held

tester.

If abnormal, check the hydraulic circuit for leakage.

05-288

05-350

05-310

05-315

32-43

ABS does not operate efficiently
BA does not operate efficiently
EBD does not operate efficiently

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. IG power source circuit and ground circuit

3. Speed sensor circuit

4. Stop light switch circuit

5. Check the ABS & Traction actuator with a hand-held

tester.

If abnormal, check the hydraulic circuit for leakage.

05-288

05-350

05-310

05-315

05-359

32-43

ABS warning light abnormal

1. ABS warning light circuit

2. Skid control ECU

05-369

05-363

DTC of ABS check cannot be done

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. Tc terminal circuit

05-288

05-380

Sensor signal check cannot be done

1. Ts terminal circuit

2. Skid control ECU

05-382

05-363

TRAC does not operate

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. IG power source circuit and ground circuit

3. Check the hydraulic circuit for leakage.

4. Speed sensor circuit

05-288

05-350

-

05-310

05-315

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DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-309

462

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

Symptom

Suspect Area

See page

VSC does not operate

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. IG power source circuit

3. Check the hydraulic circuit for leakage.

4. Speed sensor circuit

5. Deceleration sensor circuit

6. Yaw rate sensor circuit

7. Steering sensor circuit

05-288

05-350

-

05-310

05-315

05-348

05-336

05-345

SLIP indicator light abnormal

1. SLIP indicator light circuit

2. Skid control ECU

05-374

05-363

TRAC OFF indicator abnormal

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. TRAC OFF switch circuit

05-288

05-376

DTC of VSC check cannot be done

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. Tc terminal circuit

05-288

05-380

VSC warning light abnormal

If the symptoms still occur even after the following circuits
in suspect areas are inspected and proved to be normal,
replace the skid control ECU.
1. Check the DTC again and make sure that the normal

code is output.

2. VSC warning circuit

05-288

05-372

BR3583
BR3582

F00010

Rotor

+V

Speed Sensor

Magnet

Coil

N

S

To ECU

Low Speed

High Speed

-V

05-310

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DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

463

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

C0200/31 RIGHT FRONT SPEED SENSOR CIRCUIT

DTC

C0205/32 LEFT FRONT SPEED SENSOR CIRCUIT

DTC

C1235/35 FOREIGN MATTER IS ATTACHED ON TIP OF

RIGHT FRONT SENSOR

DTC

C1236/36 FOREIGN MATTER IS ATTACHED ON TIP OF

LEFT FRONT SENSOR

CIRCUIT DESCRIPTION

The speed sensor detects wheel speed and sends the ap-
propriate signals to the ECU. These signals are used for control
of the ABS and VSC control systems. Each of the front and rear
rotors has 48 serrations.
When the rotors rotate, the magnetic field emitted by the perma-
nent magnet in the speed sensor generates an AC voltage.
Since the frequency of this AC voltage changes in direct propor-
tion to the speed of the rotor, the frequency is used by the ECU
to detect the speed of each wheel.

DTC No.

DTC Detecting Condition

Trouble Area

C0200/31
C0205/32

Detection of any of conditions 1. through 3.:
1. At vehicle speed of 10 km/h (6 mph) or more, pulses are

not input for 15 sec.

2. Momentary interruption of the speed sensor signal oc-

curs at least 7 times in the time between switching the

ignition switch ON and switching it OFF.

3. The condition that the speed sensor signal circuit is

open continues for 0.5 sec. or more.

Right front and left front speed sensor

Each speed sensor circuit

Speed sensor rotor

C1235/35
C1236/36

At the vehicle speed of 20 km/h (12 mph) or more, the
condition that noise is included in the speed sensor signal
continues for 5 sec. or more.

Right front and left front speed sensor

Speed sensor rotor

HINT:
DTC No. C0200/31 and C1235/35 is the right front speed sensor.
DTC No. C0205/32 and C1236/36 is the left front speed sensor.

055VU-02

F40884

Skid Control ECU

A6
ABS Speed Sensor
Front LH

A7
ABS Speed Sensor
Front RH

28

FL+

S8

BR

27

FL-

13

FR+

12

FR-

Y

W

B

1

2

1

2

S8

S8

S8

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DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-31 1

464

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

WIRING DIAGRAM 

INSPECTION PROCEDURE

HINT:
Start the inspection from step 1 in case of using hand-held tester and start from step 2 in case of not using
hand-held  tester.

1

READ VALUE OF HAND-HELD TESTER(SPEED SENSOR OUTPUT VALUE)

(a)

Select the item ”WHEEL SPEED FL (FR)” in the DATA LIST and read its value displayed on the hand-
held tester.

(b)

Check that there is no difference between the speed value output from the speed sensor displayed
on the hand-held tester and the speed value displayed on the speedometer when driving the vehicle.
OK: There is almost no difference from the displayed speed value.

HINT:
There is tolerance of 

10 % in the speedometer indication.

OK

CHECK AND REPLACE SKID CONTROL ECU
ASSY

NG