Lexus RX300 (MCU15). Manual — part 247

DI0WG–10

DI–220

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300 (RM785E)

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

Only when 1. to 4. are all normal and the problem is still

occurring, replace the skid control ECU.

3. Check the DTC reconfirming that the normal code is

output.

4. IG power source circuit

5. Speed sensor circuit

6. Check the brake actuator with a hand–held tester.

If abnormal, check the hydraulic circuit for leakage (See

page DI–302).

DI–205

DI–263

DI–222

BR–54

ABS does not operate efficiently

Only when 1. to 4. are all normal and the problem is still

occurring, replace the skid control ECU.

1. Check the DTC reconfirming that the normal code is

output.

2. Speed sensor circuit

3. Stop light switch circuit

4. Check the brake actuator with a hand–held tester.

If abnormal, check the hydraulic circuit for leakage (See

page DI–302).

DI–205

DI–222

DI–274

BR–54

ABS warning light abnormal

1. ABS warning light circuit

2. Skid control ECU

DI–287

DI–281

BRAKE warning light abnormal

1. BRAKE warning light circuit

2. Skid control ECU

DI–290

DTC check cannot be done

Only when inspection circuits for each problem symptom

are all normal and the problem is still occurring, replace the

skid control ECU.

1. ABS warning light circuit

2. VCS warning indicator circuit

3. Tc terminal circuit

DI–287

DI–284

DI–298

Speed sensor signal check cannot be done

1. Ts terminal circuit

2. Skid control ECU

DI–300

DI–281

VSC does not operate

Only when inspection circuits for each problem symptom

are all normal and the problem is still occurring, replace

the skid control ECU.

1. Check the DTC, reconfirming 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 angle sensor circuit

DI–205

DI–263

DI–302

DI–222

DI–269

DI–260

DI–255

BA does not operate

Stop light switch circuit

DI–274

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–221

LEXUS RX300 (RM785E)

SLIP indicator light abnormal

SLIP indicator light circuit

DI–292

VSC warning light abnormal

Only when inspection circuits for each problem symptom

are all normal and the problem is still occurring, replace

the skid control ECU.

1. VSC warning indicator circuit

2. Skid control ECU

DI–284

DI7UK–02

BR3583
BR3582

F00010

Rotor

Speed Sensor

Magnet

To ECU

+V

–V

High Speed

Low Speed

Coil

N

S

DI–222

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

LEXUS RX300 (RM785E)

CIRCUIT INSPECTION

DTC

C0200 / 31 – C1239 / 39

Speed Sensor Circuit

CIRCUIT DESCRIPTION

The speed sensor detects wheel speed and sends the ap-
propriate signals to the ECU. These signals are used for control
of both the ABS & BA & VSC control system. The front and rear
rotors each have 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

C0210 / 33

C0215 / 34

Detection of any of conditions from 1. through 3.:

1. At vehicle speed of 10 km/h (6 mph) or more, pulses

are not input for 15 sec. (When RL and RR wheels are

faulty for 200 sec.)

2. Momentary interruption of the speed sensor signal

occurs at least 7 times in the time between switching

the ignition switch ON and switching it OFF.

3. The speed sensor signal circuit is open circuit

continues for 0.5 sec. or more.

S Right front, left front, right rear, left rear speed sensor

S Each speed sensor circuit

S Speed sensor rotor

C1235 / 35

C1236 / 36

C1238 / 38

C1239 / 39

Continuous noise occurs in to the speed sensor

signals with the vehicle speed at 20 km/h (12 mph)

or more continues for 5 sec or more.

S Right front, left front, right rear, left rear speed sensor

S Speed sensor rotor

HINT:

S

DTC No. C0200 / 31 and C1235 / 35 is for the right front speed sensor.

S

DTC No. C0205 / 32 and C1236 / 36 is for the left front speed sensor.

S

DTC No. C0210 / 33 and C1238 / 38 is for the right rear speed sensor.

S

DTC No. C0215 / 34 and C1239 / 39 is for the left rear speed sensor.

F05297

Skid Control ECU

Right Front
Speed Sensor

Left Front
Speed Sensor

Right Rear
Speed Sensor

Left Rear
Speed Sensor

LG

V

15

16

20

11

12

19

13

2

1

2

1

2

1

FR+

FL–

FR–

RR+

FL+

RR–

RL+

RL–

4

L

7

L

1

2

6

14

IM1

A21

P

LG

L

II1

II1

3

IM1

19

GR–R

L

GR–R

L–Y

L–W

L–Y

L–W

IM1

IM1

18

A21

A21

A21

A22

A22

A22

A22

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DIAGNOSTICS

ABS & BA & TRC & VSC SYSTEM

DI–223

LEXUS RX300 (RM785E)

WIRING DIAGRAM