Lexus ES300 (1997 year). Service manual - part 651

198

ABS

60A
ABS

2

FROM POWER SOURCE SYSTEM (SEE PAGE 56)

2

4

1

3

3

3

6

2

1

4

5

3

3

3

3

3

3

3

IM2

8

IK3

4

IK3

5

IK3

8

IK3

11

G–B

B

2

E 4

R–

B

W–

R

L–

B

W–

L

W–

R

R–

G

G–

Y

LG

–B

R

R–

W

M

B

7

B

18

B

8

A

9

A

11

A

8

A

4

B

4

1

B

10

B

11

B

21

B

22

B

5

B

12

B

16

B

9

B

1

B

4

A

1

A

5

A

3

A

7

A

4

A

8

A

2

A

6

B

5

B

3

G–

B

G

–

B

G–

B

R–

Y

LG

–R

LG

–

R

W–

R

GR

–

L

W–

B

W–

L

GR

GR

–

R

R–

L

LG

–

R

LG

–

R

R–

Y

R–L

GR–R

R–

L

SFRH

SFRR

SFLH

SFLR

SRRH

SRRR

SRLH

SRLR

MR

SR

R+

D/G

B

W–

B

W–

R

W–

B

W–B

W–

L

23

22

16

11

14

4

DATA LINK

D 3

JU

N

C

T

I

O

R

J

 8

ABS

 M

O

T

O

R

 R

E

L

A

Y

AB

S S

O

L

 R

E

L

A

Y

ABS ECU

B

A22

, A23

A

ABS ACTUATOR

B

A 5

, A 6

A

JUNCTION
CONNECTOR

IK3

6

B

B

A

C

A

3

A

A

BR

BR

BR

BR

3

BR

R–

Y

R–

L

R–L

J

U

NCT

IO

N CO

N

N

E

C

T

O

R

B

J

 8

, 

J

 9

A

JUNCTION
CONNECTOR

BR

J24

B

W–B

DATA LINK
CONNECTOR 1

D 1

1

TC

TS

MT

AST

WA

TC

TS

WB

WA

(*1

)

E1

ABS

TC

CONNECTOR 2

E1

B

B

ON

 C

O

N

N

E

C

T

C

C

C

J30

F

F

199

*  1 : SHORT PIN

FROM POWER SOURCE SYSTEM (SEE PAGE 56)

IJ1

12

A

2

A

12

W

G–

W

G–

W

G–

W

2

1

2

1

IM2

6

IM2

1

B

20

B

19

B

14

B

3

D

A

D

A

R–

L

B–

R

R–

L

G–

B

G

R

B

W

G

R

B–

R

G–B

IG1

FL–

FL+

FR–

FR+

A

[

C

JUNC

T

IO

N

CO

N

N

E

C

T

O

R

J 4

JUNC

T

IO

N

CO

N

N

E

C

T

O

R

J 3

ABS SPEED SENSOR
FRONT LH

A 9

ABS SPEED SENSOR
FRONT RH

A10

B

13

B

2

EA

E 1

1

2

1

2

A

3

A

10

A

1

A

7

ID1

3

ID1

9

IN1

3

IN1

9

W–

B

W–

B

W–

B

B

W

G

R

B

W

G

R

RR–

RR+

RL–

RL+

ABS SPEED SENSOR
REAR RH

A34

ABS SPEED SENSOR
REAR LH

A33

ABS ECU

B

A22

, A23

A

A

A

JU

N

C

T

ION

C

O

NNE

CT

O

R

J2

7

ED

BR

BR

W–

B

EB

W–

B

IM3

6

IM3

1

20

18

GR

–

R

GR

–

L

GR

–

R

GR

–

L

B

15

B

6

FRO

RRO

RRO

FRO

ABSORBER
CONTROL ECU

A24

GN

D

GN

D

ST

P

1

2

S

T

OP

 L

IGH

T

 S

W

S1

0

10A
GAUGE

1D

2

15A
ECU–IG

1J

9

15A
STOP

1C

7

B

S

 W

A

R

N

IN

G 

L

IGH

T

C

O

MB

. 

 ME

T

E

R

]

1

7

3

0

1R

4

1R

5

B

A

A

B

B

B

A

200

ABS

THIS SYSTEM CONTROLS THE RESPECTIVE BRAKE FLUID PRESSURES ACTING ON THE DISC BRAKE CYLINDERS OF THE RIGHT  FRONT
WHEEL, LEFT FRONT WHEEL AND REAR WHEELS WHEN THE BRAKES ARE APPLIED IN A PANIC STOP SO THAT THE  WHEELS DO NOT
LOCK. THIS RESULTS IN IMPROVED DIRECTIONAL STABILITY AND STEERABILITY DURING PANIC BRAKING.

1. INPUT SIGNALS

(1) SPEED SENSOR SIGNAL

THE SPEED OF THE WHEELS IS DETECTED AND INPUT TO TERMINALS FL+, FR+, RL+ AND RR+ OF THE ABS ECU.

(2) STOP LIGHT SW SIGNAL

A SIGNAL IS INPUT TO TERMINAL STP OF THE ABS ECU WHEN BRAKE PEDAL IS OPERATED.

2. SYSTEM OPERATION

DURING SUDDEN BRAKING THE ABS ECU, WHICH HAS SIGNALS INPUT FROM EACH SENSOR, CONTROLS THE CURRENT FLOWING TO
THE SOLENOID INSIDE THE ACTUATOR AND LETS THE HYDRAULIC PRESSURE ACTING ON EACH WHEEL CYLINDER ESCAPE TO THE
RESERVOIR. THE PUMP INSIDE THE ACTUATOR IS ALSO OPERATING AT THIS TIME AND IT RETURNS THE BRAKE  FLUID FROM THE
RESERVOIR TO THE MASTER CYLINDER, THUS PREVENTING LOCKING OF THE VEHICLE WHEELS.
IF THE ECU JUDGES THAT THE HYDRAULIC PRESSURE ACTING ON THE WHEEL CYLINDER IS INSUFFICIENT, THE CURRENT ACTING ON
THE SOLENOID IS CONTROLLED AND THE HYDRAULIC PRESSURE IS INCREASED. HOLDING OF THE HYDRAULIC PRESSURE IS ALSO
CONTROLLED BY THE ECU, BY THE SAME METHOD AS ABOVE. PRESSURE REDUCTION, HOLDING AND  INCREASE ARE REPEATED TO
MAINTAIN VEHICLE STABILITY AND TO IMPROVE STEERABILITY DURING SUDDEN BRAKING.

A22      , A23       ABS ECU

(CONNECT THE ECU CONNECTOR)

       2–GROUND : ALWAYS CONTINUITY
     13–GROUND : ALWAYS CONTINUITY
       2–GROUND : APPROX. 12 VOLTS WITH THE IGNITION SW AT ON POSITION
     12–GROUND : APPROX. 12 VOLTS WITH THE BRAKE PEDAL DEPRESSED

A 6       ABS ACTUATOR

1–GROUND : ALWAYS CONTINUITY

S10 STOP LIGHT SW

2–1 : CLOSED WITH THE BRAKE PEDAL DEPRESSED

: PARTS LOCATION

CODE

SEE PAGE

CODE

SEE PAGE

CODE

SEE PAGE

A 5

A

26

A33

30

J 8

A

29

A 6

B

26

A34

30

J 9

B

29

A 9

26

C10

28

J24

29

A10

26

D 1

26

J27

29

A22

A

28

D 3

28

J30

29

A23

B

28

J 3

29

S10

29

A24

28

J 4

29

: RELAY BLOCKS

CODE

SEE PAGE

RELAY BLOCKS (RELAY BLOCK LOCATION)

3

23

ENGINE ROOM NO. 3 R/B (RADIATOR UPPER SUPPORT RH)

,,,

,,,

,,,

: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR

CODE

SEE PAGE

JUNCTION BLOCK AND WIRE HARNESS (CONNECTOR LOCATION)

1C

24

COWL WIRE AND INSTRUMENT PANEL J/B (LOWER FINISH PANEL)

1D

24

INSTRUMENT PANEL WIRE AND INSTRUMENT PANEL J/B (LOWER FINISH PANEL)

1J

24

COWL WIRE AND INSTRUMENT PANEL J/B (LOWER FINISH PANEL)

1R

24

COWL WIRE AND INSTRUMENT PANEL J/B (LOWER FINISH PANEL)

SERVICE HINTS

SYSTEM OUTLINE

201

: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS

CODE

SEE PAGE

JOINING WIRE HARNESS AND WIRE HARNESS (CONNECTOR LOCATION)

ID1

36

FLOOR WIRE AND COWL WIRE (LEFT KICK PANEL)

IJ1

38

INSTRUMENT PANEL WIRE AND COWL WIRE (UNDER THE GLOVE BOX)

IK3

38

ENGINE WIRE AND COWL WIRE (UNDER THE GLOVE BOX)

IM2

38

RIGHT RADIATOR SIDE SUPPORT

IM3

38

ENGINE ROOM MAIN WIRE AND COWL WIRE (RIGHT KICK PANEL)

IN1

38

FLOOR NO. 2 WIRE AND COWL WIRE (RIGHT KICK PANEL)

: GROUND POINTS

CODE

SEE PAGE

GROUND POINTS LOCATION

EA

34

RIGHT RADIATOR SIDE SUPPORT

EB

34

RIGHT RADIATOR SIDE SUPPORT

ED

34

SURGE TANK RH

: SPLICE POINTS

CODE

SEE PAGE

WIRE HARNESS WITH SPLICE POINTS

CODE

SEE PAGE

WIRE HARNESS WITH SPLICE POINTS

E 1

34

ENGINE ROOM MAIN WIRE

1

2

3

4

5

6

7

8

1

2

3

4

5

1

2

1

2

1 2

3

4 X X

7 8

9 10 11 12

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 X 18 19 20 21 22

X

X

18

20

X X X

1

2

1

2

7

3

X X

X

X

X

X

X 11

X X

X

16 X

X

X

X

23

22

X

X

X

4

X

X

X

X

X

X

X

X

14

X

A BLACK

A 5

B GRAY

A 6

A

A22

B

A23

A 9 GRAY

A10 GRAY

A24 GRAY

A33 GRAY

A34 GRAY

D 3 DARK GRAY

D 1 BLACK

C10 BROWN

3

3