Lexus ES300 (2002 year). Manual — part 313

F41981

FL MAIN

S8

R-W

Battery

W

1

Combination Meter

Skid Control ECU

Driver Side J/B

Brake Fluid Level
Warning SW

2

25

1

C7

C8

ALT

LBL-

LBLO

Brake

B-Y

Passenger Side J/B

3

I14
Ignition SW

S7

8

S7

21

PKB

17

2R

5

2P

7

2M

8

2G

11

B-G

2A

1

87

2

2E

2

3A

4

IG1 Relay

8

IA

IG1 AM1

W-B

ED

1

Engine Room R/B

B-G

1

W-B

40

W

R-W

R-W

R-W

B1

P5
Parking
Brake SW

GAUGE1

AM1

2

1

2A

2

2

W

W

W

3A

57

1

05-370

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

523

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

BRAKE WARNING LIGHT CIRCUIT

CIRCUIT DESCRIPTION

If the ECU detects trouble, it lights the brake warning light while prohibiting ABS control. At this time, the ECU
records a DTC in memory.
Connect terminals Tc and CG of the DLC3 to make the brake warning light blink and output the DTC.

WIRING DIAGRAM

INSPECTION PROCEDURE

1

CHECK PARKING BRAKE SWITCH CIRCUIT

NG

REPAIR OR REPLACE PARKING BRAKE
SWITCH CIRCUIT

OK

052B5-03

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-371

524

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

2

CHECK BRAKE FLUID LEVEL WARNING SWITCH CIRCUIT

NG

REPAIR OR REPLACE BRAKE FLUID LEVEL
WARNING SWITCH CIRCUIT

OK

3

RECONFIRM DTC(See page

05-288

)

A

Normal Code

B

Malfunction Code

B

REPAIR CIRCUIT INDICATED BY OUTPUT
CODE

A

4

INSPECT COMBINATION METER ASSY(BRAKE WARNING LIGHT CIRCUIT)

NG

REPAIR OR REPLACE COMBINATION METER
ASSY

OK

5

CHECK HARNESS AND CONNECTOR(COMBINATION METER - SKID CONTROL
ECU ASSY)(See page

01-31

)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

CHECK AND REPLACE SKID CONTROL ECU ASSY

F41992

Skid Control ECU

Combination Meter

14

VSCW

S7

Engine Room J/B

Driver Side J/B

From
Ignition SW

R-L

B-R

B-O

IG2

8

5

2O

8

2G

1C

C8

13

7

1C

C7

39

W

B-O

VSC

IF6

8

B-R

05-372

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

525

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

VSC WARNING LIGHT CIRCUIT

CIRCUIT DESCRIPTION

If the ECU stores DTC, the VSC warning light lights on the combination meter.

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(VSC WARNING LIGHT
CIRCUIT)

(a)

Select the item ”VSC WARN LIGHT” in the ACTIVE TEST and operate the VSC warning light on the
hand-held tester.

(b)

Check that ”ON” and ”OFF” of the VSC warning light can be shown on the combination meter with the
hand-held tester.

OK

CHECK AND REPLACE SKID CONTROL ECU
ASSY

NG

2

INSPECT VSC WARNING LIGHT

(a)

See combination meter troubleshooting on page

71-1

.

NG

REPAIR OR REPLACE COMBINATION METER
ASSY

OK

055W6-02

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-373

526

2002 LEXUS ES300 REPAIR MANUAL (RM911U)

3

CHECK HARNESS AND CONNECTOR(SKID CONTORL ECU ASSY -
COMBINATION METER)(See page

01-31

)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

CHECK AND REPLACE SKID CONTROL ECU ASSY