Lexus ES300 (1997 year). Manual — part 366

F00048

1 2

(+)

(–)

Engine Room
R/B No. 3

3

4 5 6

1 2

(+)

(–)

Engine Room
R/B No. 3

3

4 5 6

1 2

(+)

(–)

Engine Room
R/B No. 3

3

4 5 6

1 2

(+)

(–)

Engine Room
R/B No. 3

3

4 5 6

F00053

3

ABS
Solenoid
Relay

A6

4

A6

5

A23

AST

ECU

ABS

Actuator

3

ABS
Solenoid
Relay

A6

4

A6

5

A23

AST

ECU

ABS

Actuator

3

ABS
Solenoid
Relay

A6

4

A6

5

A23

AST

ECU

ABS

Actuator

3

ABS
Solenoid
Relay

A6

4

A6

5

A23

AST

ECU

ABS

Actuator

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–241

393

1997 LEXUS ES300 (RM511U)

INSPECTION PROCEDURE

1

Check voltage between terminals 1 and 2 of Engine Room R/B No. 3 (for ABS so-
lenoid relay).

PREPARATION:
Remove ABS solenoid relay from Engine Room R/B No. 3.
CHECK:
Measure the voltage between terminals 1 and 2 of Engine
Room R/B No. 3 (for ABS solenoid relay).
OK:

Voltage: 10 – 14 V

NG

Check and repair harness or connector.

OK

2

Check continuity between terminal 3 of ABS solenoid relay and terminal AST of
ABS ECU.

CHECK:
Check continuity between terminal 3 of ABS solenoid relay and
terminal AST of ABS ECU.
OK:

Continuity

HINT:There is a resistance of 4

∼

6

Ω

between terminals A6 –

4 and A6 – 5 of ABS actuator.

NG

Repair or replace harness or ABS actuator.

OK

F00042

1

2

3

4

5

6

(+)

(–)

1

2

3

4

5

6

1

2

3

4

5

6

Open

Continuity

Continuity

Continuity

Open

DI–242

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

394

1997 LEXUS ES300 (RM511U)

3

Check ABS solenoid relay.

PREPARATION:
Remove ABS solenoid relay from Engine Room R/B No. 3.

CHECK:
Check continuity between each terminal of ABS solenoid relay.
OK:

Terminals 4 and 6

Continuity (Reference value 80

Ω

)

Terminals 2 and 3

Continuity

Terminals 1 and 3

Open

CHECK:
(a)

Apply battery positive voltage between terminals 4 and 6.

(b)

Check continuity between each terminal of ABS solenoid
relay.

OK:

Terminals 2 and 3

Open

Terminals 1 and 3

Continuity

NG

Replace ABS solenoid relay.

OK

4

Check for open and short in harness and connector between ABS solenoid relay
and ABS ECU (See page

IN–27

).

NG

Repair or replace harness or connector.

OK

If the same code is still output after the DTC is deleted, check the contact condition of each con-
nection.
If the connector are normal, the ECU may be defective.

F00112

Engine Room R/B No. 3

Battery

MAIN

B–G

F6

F9

FL
Block

ABS

1

2

3

4

A6

EA

EB

W–B

ABS Actuator

ABS Motor
Relay

ABS ECU

1

ALT

1

3

3

3

W–B

W–B

A6

A6

2

1

3

1

2

3

B–G

W–R

A23

A23

A23

7

8

9

GR–L

GR–R

R–W

MR

R+

MT

Engine Room R/B No. 3

Battery

MAIN

B–G

F6

F9

FL
Block

ABS

1

2

3

4

A6

EA

EB

W–B

ABS Actuator

ABS Motor
Relay

ABS ECU

1

ALT

1

3

3

3

W–B

W–B

A6

A6

2

1

3

1

2

3

B–G

W–R

A23

A23

A23

7

8

9

GR–L

GR–R

R–W

MR

R+

MT

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–243

395

1997 LEXUS ES300 (RM511U)

DTC

13, 14

ABS Motor Relay Circuit

CIRCUIT DESCRIPTION

The ABS motor relay supplies power to the ABS pump motor. While the ABS is activated, the ECU switches
the ABS motor relay ON and operates the ABS pump motor.

DTC No.

DTC Detecting Condition

Trouble Area

13

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

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

when motor relay is ON in the midst of initial check

or in operation of ABS control, ABS ECU terminal MT

voltage is less than 4 V.

(2) Motor relay is ON driving in the midst of initial check or

in operation of ABS control, ABS ECU terminal IG1

voltage becomes 9.5 V or less and ABS ECU terminal

MT voltage is less than 4 V.

ABS motor relay

ABS motor relay circuit

14

When motor relay is OFF, ABS ECU terminal MT voltage is

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

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

WIRING DIAGRAM

DI0BJ–01

F00049

1

(+)

(–)

Engine Room
R/B No. 3

2

3 4

1

(+)

(–)

Engine Room
R/B No. 3

2

3 4

1

(+)

(–)

Engine Room
R/B No. 3

2

3 4

1

(+)

(–)

Engine Room
R/B No. 3

2

3 4

F00054

ABS
Motor
Relay

2

A6

A6

A23

MT

2

2

3

3

M

ECU

ABS

Actuator

ABS
Motor
Relay

2

A6

A6

A23

MT

2

2

3

3

M

ECU

ABS

Actuator

ABS
Motor
Relay

2

A6

A6

A23

MT

2

2

3

3

M

ECU

ABS

Actuator

ABS
Motor
Relay

2

A6

A6

A23

MT

2

2

3

3

M

ECU

ABS

Actuator

DI–244

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

396

1997 LEXUS ES300 (RM511U)

INSPECTION PROCEDURE

1

Check voltage between terminal 1 of Engine Room R/B No. 3 (for ABS motor
relay) and body ground.

PREPARATION:
Remove ABS motor relay from Engine Room R/B No. 3.
CHECK:
Measure voltage between terminal 1 of Engine Room R/B No.
3 (for ABS motor relay) and body ground.
OK:

Voltage: 10 – 14 V

NG

Check and repair harness or connector.

OK

2

Check continuity between terminal 2 of ABS motor relay and terminal MT of ABS
ECU.

CHECK:
Check continuity between terminal 2 of ABS motor relay and
terminal MT of ABS ECU.
OK:

Continuity

HINT:There is a resistance of 4

∼

6

Ω

between terminals A6 –

2 and A6 – 3 of ABS actuator.

NG

Repair or replace harness or ABS actuator.

OK