Lexus ES300 (2002 year). Manual - part 302

F12723

3

BS

AST

S7

AST

Skid 

Control ECU

ABS SOL 

Relay

ABS-3  Fuse

Brake Actuator

Engine Room R/B

F41243

ABS No. 4

ABS R/B

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-329

482

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

4

CHECK CONTINUITY(ABS & TRACTION ACTUATOR - SKID CONTROL ECU
ASSY)

(a)

Disconnect the connector from the skid control ECU.

(b)

Check continuity between terminal 3 of engine room R/B
(for ABS solenoid relay) and terminal AST of skid control
ECU
OK: Continuity

OK

REPLACE ABS & TRACTION ACTUATOR ASSY

NG

5

CHECK HARNESS AND CONNECTOR(ABS SOLENOID RELAY - SKID CONTROL
ECU ASSY)(See page 

01-31

)

OK

IF THE SAME CODE IS STILL OUTPUT AFTER
THE DTC IS DELETED, CHECK THE CONTACT
THE CONDITION OF EACH CONNECTION

NG

6

INSPECT FUSE(ABS NO.4 OF ABS R/B)

(a)

Remove ABS No. 4 fuse from the ABS R/B.

(b)

Check continuity of fuse.
OK: Continuity

NG

REPLACE FUSE

OK

CHECK AND REPAIR HARNESS AND CONNECTOR

F41242

ABS No. 3

05-330

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

483

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

7

INSPECT FUSE(ABS NO.3 OF ENGINE ROOM J/B)

(a)

Remove ABS No. 3 fuse from the engine room J/B.

(b)

Check continuity of fuse.
OK: Continuity

NG

REPLACE FUSE

OK

CHECK AND REPAIR HARNESS AND CONNECTOR

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-331

484

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

C1201/51 ENGINE CONTROL SYSTEM MALFUNCTION

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1201/51

Conditions 1. and 2. continue for 5 sec.:
1. Engine speed: 500 rpm or more.

2. A trouble signal in the engine control system is input.

Engine control system

HINT:
If trouble occurs in the engine control system, the ECU prohibits TRAC and VSC control.

INSPECTION PROCEDURE

1

CHECK DTC FOR ENGINE(See page 

05-5

)

A

Normal Code

B

Malfunction Code

B

REPAIR ENGINE CONTROL SYSTEM
ACCORDING TO CODE OUTPUT

A

CHECK AND REPLACE ECM

0529K-03

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

05-332

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

485

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

C1202/52 BRAKE FLUID LEVEL LOW/OPEN CUIRCUIT

IN BRAKE FLUID LEVEL WARNING SWITCH
CIRCUIT

CIRCUIT DESCRIPTION

The brake fluid level warning switch sends the appropriate signal to the ECU when the brake fluid level drops.
HINT:
Depress the parking brake pedal and also turns on the brake warning light but does not diagnose DTC No.
C1202 / 52.

DTC No.

DTC Detecting Condition0

Trouble Area

C1202 / 52

ECU terminal IG1 voltage is 9.5 V to 17.2 V and open cir-
cuit for the brake fluid level warning switch circuit continues
for 2 sec. or more.

Brake fluid level

Brake fluid level warning switch

Brake fluid level warning switch circuit

WIRING DIAGRAM

056AM-01