Lexus ES300 (2002 year). Manual - part 283

F41939

Battery

24

W-B

2

+BM

GND

23

W-B

5

ABS No. 2

Engine Room R/B

S1

1G

1A

1

Engine Room J/B

EA

1

2

L

FL MAIN

B-G

Skid Control ECU with Actuator

1

Motor
Relay

GND

1

1

2

ALT

B-G

S1

S1

W-B

EB

W-B

W-B

-

DIAGNOSTICS

ABS WITH EBD SYSTEM

05-261

414

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

C0273/13 OPEN CIRCUIT IN ABS MOTOR RELAY

CIRCUIT

DTC

C0274/14 B+ SHORT CIRCUIT IN 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 Detection Condition

Trouble Area

C0273/13

Condition 1. or 2. continues for 0.2 sec. or more:

1. ABS ECU terminal IG1 voltage is 9.5 V to 18.5 V, and

when motor relay is ON in the midst of initial check or in

operation of ABS control.*

1

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

in operation of ABS control, ABS ECU terminal IG1 volt-

age becomes 9.5 V or less.*

2

Fusible link block

ABS No. 3 fuse

ABS motor relay

ABS motor relay circuit

C0274/14

Condition below continues for 4 sec. or more:

When the motor relay is OFF, there is open circuit in MT

terminal of ABS ECU.

ABS motor relay circuit

WIRING DIAGRAM

055XP-02

F13036

LOCK

(-)

(+)

23

24

2

05-262

-

DIAGNOSTICS

ABS WITH EBD SYSTEM

415

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

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

(a)

Select the item ”ABS MOT RELAY” in the ACTIVE TEST and operate the ABS motor relay on the hand-
held tester.

(b)

Check the operation sound of the ABS motor relay when operating it with the hand-held tester.
OK:
The operation sound of the pump motor should be heard.

NG

CHECK AND REPLACE BRAKE ACTUATOR
ASSY

OK

2

CHECK TERMINAL VOLTAGE(+BM AND GND OF SKID CONTROL ECU)

(a)

Disconnect the skid control ECU connector.

(b)

Measure the voltage between terminals 23 and 2 or 24 of
the skid control ECU connector.
OK: 11 - 14 V

NG

CHECK AND REPAIR HARNESS AND
CONNECTOR

OK

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

F41938

Battery

1

+BS

Skid Control ECU with Actuator

7

S1

1E

1A

1

Engine 
Room 
J/B

ABS No. 3

L

B-G

Solenoid 

Relay

SFLH

SRLH

SFRR

SRRR

SFLR

SRLR

SFRH

SRRH

1

2

Engine 
Room 
R/B

ALT

1

2

1

1

B-G

FL 
MAIN

-

DIAGNOSTICS

ABS WITH EBD SYSTEM

05-263

416

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

C0278/11 OPEN CIRCUIT IN ABS SOLENOID RELAY

CIRCUIT

DTC

C0279/12 SHORT CIRCUIT IN ABS SOLENOID RELAY

CIRCUIT

CIRCUIT DESCRIPTION

This relay supplies power to each ABS solenoid. After the ignition switch is turned ON, if the initial check is
OK, the relay turns on.

DTC No.

DTC Detection Condition

Trouble Area

C0278/11

Condition 1. or 2. continues for 0.2 sec. or more:

1. IG1 terminal voltage of skid control ECU is 9.5 - 18.5 V,

and when the solenoid relay is ON.*

1

2. With solenoid relay ON driving, when IG terminal of skid

control ECU is less than 9.5 V.*

1

Fusible link block

ABS No. 2 fuse

ABS solenoid relay

ABS solenoid relay circuit

C0279/12

Immediately after IG switch has been turned ON, when the

solenoid relay is OFF.*

2

ABS solenoid relay circuit

*

1

 Solenoid relay contact OFF condition:

All of solenoid terminal voltage is half of IG terminal voltage or less than.
*

2 

Solenoid relay contact ON condition:

All of solenoid terminal voltage is half of IG terminal voltage or more.

WIRING DIAGRAM

055XQ-02

F13037

LOCK

(-)

(+)

2

24

1

05-264

-

DIAGNOSTICS

ABS WITH EBD SYSTEM

417

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

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(ABS SOLENOID RELAY
OPERATION)

(a)

Select the item ”ABS SOL RELAY” in the ACTIVE TEST and operate the ABS solenoid relay on the
hand-held tester.

(b)

Check the operation sound of the ABS solenoid relay when operating it with the hand-held tester.
OK: The operation sound of the ABS solenoid should be heard.

OK

CHECK AND REPLACE BRAKE ACTUATOR
ASSY

NG

2

CHECK TERMINAL VOLTAGE(+BS AND GND OF SKID CONTROL ECU)

(a)

Disconnect the skid control ECU connector.

(b)

Measure the voltage between terminals 1 and 2 or 24 of
the skid control ECU connector.
OK: 11 - 14 V

NG

CHECK AND REPAIR HARNESS AND
CONNECTOR

OK

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