Lexus ES300 (1997 year). Manual - part 370

F00105

Battery

MAIN

B–G

F6

F11

1

ALT

FL Block

B–R

STOP

Instrument Panel J/B

1C

1B

4

7

Stop Light 
Switch

2

G–W

1R

1S

5

J27

Light Failure 
Sensor

J/C
J37

BN

BP

W–B

G–W

A22

12

STP

ABS ECU

R

G–R

High
Mounted
Stop
Light

Right
Stop
Light

Left
Stop
Light

A

1

Instrument 
Panel J/B

G–R

W

1

1R

2

4

G–W

G–R

W–B

W–B

W–B

H11

R6

R8

H11

R8

R6

2

1

3

3

1

1

G–W

J/C

A

A

7

2

1

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–257

409

1997 LEXUS ES300   (RM511U)

DTC

49

Stop Light Switch Circuit

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

49

ABS ECU terminal IG1 voltage is 9.5 V to 18.0 V and ABS

is in non–operation, the open circuit of the stop light switch

circuit continues for 0.3 sec. or more.

Stop light switch

Stop light switch circuit

WIRING DIAGRAM

INSPECTION PROCEDURE

1

Check operation of stop light.

CHECK:
Check that stop light lights up when brake pedal is depressed and turns off when brake pedal is released.

NG

Repair stop light circuit (See page 

BE–50

).

DI0BO–01

W01410

(+)

(–)

STP

DI–258

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

410

1997 LEXUS ES300   (RM511U)

OK

2

Check voltage between terminal STP of ABS ECU and body ground.

PREPARATION:
Remove ABS ECU with connectors still connected.
CHECK:
Measure voltage between terminal STP of ABS ECU and body
ground when brake pedal is depressed.
OK:

Voltage: 8 – 14 V

OK

Proceed to next circuit inspection shown on
problem symptoms table (See page 

DI–239

).

NG

3

Check for open in harness and connector between ABS ECU and stop light
Switch (See page 

IN–27

).

NG

Repair or replace harness or connector.

OK

Check and replace ABS ECU.

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

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

DI–259

411

1997 LEXUS ES300   (RM511U)

DTC

51

ABS Pump Motor Lock

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

51

ABS actuator pump motor is not operating normally.

ABS pump motor

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

WIRING DIAGRAM

DI0BP–01

DI–260

–

DIAGNOSTICS

ANTI–LOCK BRAKE SYSTEM

412

1997 LEXUS ES300   (RM511U)

DTC

Always ON

ABS ECU Malfunction

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

Always ON

ABS ECU internal malfunction is detected.

ECU

Battery

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

INSPECTION PROCEDURE

1

Is DTC output?

Check DTC on page 

DI–232

.

YES

Repair circuit indicated by the code output.

NO

2

Is normal code displayed?

YES

Check ABS solenoid relay. Check for short in
harness and connector between ABS solenoid
relay and DLC1 (See page 

IN–27

).

NO

3

Is ABS warning light go off?

YES

Check for open or short in harness and connec-
tor between ECU–IG fuse and ABS ECU 
(See page 

IN–27

).

NO

DI0BQ–01