Lexus ES300 (2002 year). Manual - part 315

F41994

Skid Control ECU

1

BZ

Passenger Side J/B

V11
VSC Warning Buzzer

68

8

6

W

Buzzer

3B

2L

2R

3B

29

S7

5

B-R

P-B

2

From Battery

From Ignition SW

W-B

Driver Side J/B

ECU-IG

IG1 Relay

3

5

2

1

8

2E

2A

2

B-Y

B-G

IA

05-378

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

531

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

VSC BUZZER CIRCUIT

CIRCUIT DESCRIPTION

The skid control buzzer sounds during VSC operation.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:
Start the inspection from step 1 in case of using the hand-held tester and start from step 2 in case of not
using the hand-held tester.

1

PERFORM ACTIVE TEST BY HAND-HELD TESTER(SKID CONTROL BUZZER
OPERATION)

(a)

Select the item ”VSC/BR WARN BUZ” in the ACTIVE TEST and operate the skid control buzzer on
the hand-held tester.

(b)

Check that skid control buzzer sounds ”ON” and ”OFF” with the hand-held tester.

OK

CHECK AND REPLACE SKID CONTROL ECU
ASSY

NG

052B6-03

F02192

1

2

(+)

(-)

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-379

532

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

2

INSPECT SKID CONTROL BUZZER ASSY

(a)

Disconnect the skid control buzzer connector.

(b)

Apply battery positive voltage to the terminals 1 and 2 of
skid control buzzer connector, check that the buzzer
sounds.

NG

REPLACE SKID CONTROL BUZZER ASSY

OK

3

CHECK HARNESS AND CONNECTOR(SKID CONTROL BUZZER - SKID
CONTROL ECU)(See page 

01-31

)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

CHECK AND REPLACE SKID CONTROL ECU ASSY

F41999

Skid Control ECU

71

TC

19

S7

P-B

D3

DLC3

TC

CG

80

70

Passenger Side J/B

SB

IA

4

13

P-B

3B

3B

3B

3B

21

Driver Side J/B

2L

2R

8

8

W-B

W-B

C52361

Tc

CG

DLC3

05-380

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

533

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

TC TERMINAL CIRCUIT

CIRCUIT DESCRIPTION

Connecting terminals Tc and CG of the DLC3 causes the ECU to display the DTC by flashing the ABS warn-
ing light.

WIRING DIAGRAM

INSPECTION PROCEDURE

1

INSPECT DLC3(TC TERMINAL VOLTAGE)

(a)

Turn the ignition switch ON.

(b)

Measure voltage between terminals Tc and CG of DLC3.
OK: 10 - 14 V

OK

Go to step 3

NG

052B7-03

C52361

Tc

CG

DLC3

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-381

534

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

2

CHECK HARNESS AND CONNECTOR(SKID CONTROL ECU ASSY - DLC3, DLC3
- BODY GROUND)

(a)

Check for open and short circuit in harness and connector between terminal Tc of the skid control ECU
and DLC3 (See page 

01-31

).

(b)

Check for open circuit in harness and connector between terminal CG of the DLC3 and body ground
(See page 

01-31

).

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

CHECK AND REPLACE SKID CONTROL ECU ASSY

3

INSPECT ABS AND VSC WARNING LIGHT

SST

09843-18040

(a)

Using SST, connect the terminals Tc and CG of the DLC3.

(b)

Turn the ignition switch ON.

(c)

Check the ABS and VSC warning right.
OK: Warning light blinking

OK

END

NG

CHECK AND REPLACE SKID CONTROL ECU ASSY