Lexus ES300 (1997 year). Manual — part 365

DI0BF–01

F00077

DLC1

DLC2

ABS Warning Light

Front Speed Sensor

Sensor Rotor

Rear Speed Sensor

ABS Actuator

ABS ECU

Stop Light Switch

ABS Solenoid
Relay

ABS Motor Relay

Sensor Rotor

Front Speed Sensor

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–237

389

1997

L

EXUS ES300 (RM51

1

U

)

P

ARTS

LOCA

TION

DI0BG–01

BR5385

A22

A23

1

2

3

4

8

5

6

7

9

10

11

12

13

14

15

16

17

18

19

20

21

22

1

2

3

4

5

6

7

8

9

10

11

12

DI–238

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

390

1997 LEXUS ES300 (RM511U)

TERMINALS OF ECM

Symbols (Terminals No.)

STD Voltage (V)

Condition

IG1(A22 – 2) – GND (A23 – 2, 13)

10 – 14

IG switch ON

R+ (A23 – 8) – SR (A23 – 18)

9 – 14

IG switch ON, ABS warning light OFF

R+ (A23 – 8) – MR (A23 – 7)

Below 1.0

IG switch ON

SFRR (A23 – 1) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

SFRH (A23 – 4) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

SFLR (A23 – 11) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

SFLH (A23 – 10) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

SRRR (A23 – 22) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

SRRH (A23 – 21) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

SRLR (A23 – 12) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

SRLH (A23 – 5) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

AST (A23 – 16) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

WA (A22

4)

GND (A23

2 13)

Below 2.0

IG switch ON, ABS warning light ON

WA (A22 – 4) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

STP (A22

12)

GND (A23

2 13)

Below 1.5

Stop light switch OFF

STP (A22 – 12) – GND (A23 – 2, 13)

8 – 14

Stop light switch ON

D/G (A22 – 11) – GND (A23 – 2, 13)

10 – 14

IG switch ON, ABS warning light OFF

Tc (A22 – 9) – GND (A23 – 2, 13)

8 – 14

IG switch ON

Ts (A22 – 8) – GND (A23 – 2, 13)

8 – 14

IG switch ON

FR+ (A23 – 3) – FR– (A23 – 14)

AC generation

IG switch ON

Slowly turn right front wheel

FL+ (A23 – 19) – FL– (A23 – 20)

AC generation

IG switch ON

Slowly turn left front wheel

RR+ (A22 – 1) – RR– (A22 – 7)

AC generation

IG switch ON

Slowly turn right rear wheel

RL+ (A22 – 3) – RL– (A22 – 10)

AC generation

IG switch ON

Slowly turn left rear wheel

MT (A23 – 9) – GND (A23 – 2, 13)

Below 1.5

IG switch ON

DI0BH–01

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–239

391

1997 LEXUS ES300 (RM511U)

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.

Symptoms

Inspection Circuit

See page

ABS does not operate.

Only when 1.

∼

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

ABS ECU.

1. Check the DTC reconfirming that the normal code is output.

2. IG power source circuit.

3. Speed sensor circuit.

4. Check the ABS actuator with a checker.

If abnormal, check the hydraulic circuit for leakage (See page

DI–269

).

DI–232

DI–254

DI–248

BR–46

ABS does not operate

efficiently.

Only when 1.

∼

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

ABS ECU.

1. Check the DTC reconfirming that the normal code is output.

2. Speed sensor circuit.

3. Stop light switch circuit.

4. Check the ABS actuator with a checker.

If abnormal, check the hydraulic circuit for leakage (See page

DI–269

).

DI–232

DI–248

DI–257

BR–46

ABS warning light

abnormal.

1. ABS warning light circuit.

2. ABS ECU.

DI–262

DI–260

DTC check cannot be done.

Only when 1. and 2. are all normal and the problem is still occurring, replace the

ABS ECU.

1. ABS warning light circuit.

2. Tc terminal circuit.

DI–262

DI–265

Speed sensor signal check

cannot be done.

1. Ts terminal circuit.

2. ABS ECU.

DI–267

DI–260

DI0BI–01

F00080

Engine Room R/B No. 3

ABS Solenoid Relay

ABS

Battery

MAIN

B–G

2

1

3

DLC1

ABS ECU

EA

EB

A23

4

5

6

16

GR

W–B

A6

GR–R

ABS
Actuator

W–L

ALT

A6

5

4

3

3

3

3

3

3

W–B

W–B

B–G

A23

A23

2

1

8

18

SR

R+

AST

FL
Block

F6

F9

1

1

R

ABS ECU

Engine Room R/B No. 3

ABS Solenoid Relay

ABS

Battery

MAIN

B–G

2

1

3

DLC1

ABS ECU

EA

EB

A23

4

5

6

16

GR

W–B

A6

GR–R

ABS
Actuator

W–L

ALT

A6

5

4

3

3

3

3

3

3

W–B

W–B

B–G

A23

A23

2

1

8

18

SR

R+

AST

FL
Block

F6

F9

1

1

R

ABS ECU

DI–240

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

392

1997 LEXUS ES300 (RM511U)

CIRCUIT INSPECTION

DTC

11, 12

ABS Solenoid Relay Circuit

CIRCUIT DESCRIPTION

This relay supplies power to each ABS solenoid. After the ignition switch is turned ON, if the initial check is
OK, the relay goes on.

DTC No.

DTC Detecting Condition

Trouble Area

11

Condition (1) or (2) continue for 0.2 sec. or more:

(1) ABS ECU terminal IG1 voltage is 9.5 V to 18.0 V, and

when solenoid relay is ON, ABS ECU terminal AST

voltage is less than 4 V.

(2) With solenoid relay is ON driving, ABS ECU terminal

IG1 voltage becomes 9.5 V or less, and ABS ECU

terminal AST voltage is less than 4 V.

ABS solenoid relay

ABS solenoid relay circuit

12

Immediately after turning ignition switch ON, and when

solenoid relay is OFF, ABS ECU terminal AST voltage is

4 V or more continues for 0.2 sec. or more.

Fail safe function: If trouble in the ABS solenoid relay circuit, the ECU cuts off current to the ABS solenoid
relay and prohibits ABS control.

WIRING DIAGRAM