Lexus ES300 (2002 year). Manual - part 306

F07812

SM1-

SRC2

SM2-

SRC1

SM2+

SRM2

SRM1

SM1+

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-343

496

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

INSPECTION PROCEDURE

1

INSPECT ABS & TRACTION ACTUATOR ASSY(SRM1, SRM2, SCR1, SCR2, SM1,
SM2 SOLENOID)

(a)

Disconnect the brake actuator connector.

(b)

Check continuity between terminals SM1+ - SM1-, and
terminals SM2+ - SM2- of brake actuator.
OK: Continuity

HINT:
Resistance of each solenoid: 8.1 - 9.1 

Ω

(c)

Check continuity between terminal BS and terminals
SRC1, SRC2, SRM1 and SRM2 of brake actuator.
OK: Continuity

HINT:
Resistance of each solenoid
SRC1, SRC2: 8.1 - 9.1 

Ω

SRM1, SRM2: 4.9 - 5.5 

Ω

NG

REPLACE ABS & TRACTION ACTUATOR ASSY

OK

2

CHECK HARNESS AND CONNECTOR(ABS & TRACTION ACTUATOR  ASSY  -
SKID CONTROL ECU ASSY)(See page 

01-31

)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

3

CHECK SKID CONTROL ECU TERMINAL VOLTAGE(SR TERMINAL)

(a)

Remove the skid control ECU with connectors still connected.

(b)

Turn the ignition switch ON, measure between terminal SR and GND.
OK: 1V or less

NG

CHECK AND REPAIR HARNESS AND ABS
SOLENOID RELAY

OK

4

RECONFIRM DTC(See page 

05-288

)

A

Malfunction Code

B

Normal Code

B

END

A

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DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

497

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

5

CHECK CONTACT CONDITION(EACH CONNECTION)

NG

CHECK AND REPAIR HARNESS AND
CONNECTOR

OK

CHECK AND REPLACE SKID CONTROL ECU ASSY

F41985

Skid Control ECU

3

Battery

IA

FL MAIN

B-G

AM1

IG1

5

2

Engine 
Room R/B

Driver Side J/B

Engine Room J/B

1

AM1

ECU-IG

ECU-B

2P

2L

2A

2A

2R

2E

2F

7

2

8

1D

1A

6

6

8

2

IF4

21

22

S8

+BI

W-R

B-Y

W

W

1

2

1

1

1

1

2

B-G

3B

3B

S7

S6

S6

S6

18

27

24

6

P

V

P

Y-R

10

9

3

D

SS1+

SS1-

+BO

TRIG

I14 
Ignition SW

S9
Steering Sensor

Passenger Side J/B

A

A

W-B

W

28

68

ALT

W-B

B-G

R

W-R

2

4

SS1+

SS1-

BAT

TRIG

IG

ESS

1

2

B-R

J4
J/C

D.C.C

IG Relay

W-B

IB

A

J1
J/C

11

D

J3
J/C

W-R

B-G

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

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2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

C1231/31 MALFUNCTION IN STEERING ANGLE

SENSOR CIRCUIT

DTC

C1335/35 STEERING ANGLE SENSOR CIRCUIT

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1231/31

When ECU IG1 terminal voltage is 9.5 V or more, ECU
does not receive data from the steering angle sensor for 1
sec. or more.

Steering angle sensor

Steering angle sensor circuit

+BI circuit

C1335/35

Detection of either condition 1. or 2.:
1. When the ECU IG1 terminal voltage is 9.5 V or more,

data transmission from the steering angle sensor is im-

possible for 1 sec or more

Steering angle sensor

C1335/35

possible for 1 sec. or more.

2. Immediately after the terminal BAT is connected and

when IG1 terminal voltage is 9.5 V or more, open circuit

of terminal TRIG continues for 15 sec. or more.

Steering angle sensor

Steering angle sensor circuit

WIRING DIAGRM

0529N-03

F40906

ON

GND

GND

GND

GND

+B1

F43002

ON

2 (-)

9 (+)

1 (+)

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DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

499

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

INSPECTION PROCEDURE

1

INSPECT SKID CONTROL ECU TERMINAL VOLTAGE(+BI TERMINAL)

(a)

Remove the skid control ECU with the connector still con-
nected.

(b)

Turn the ignition switch ON.

(c)

Measure voltage between terminal +BI and GND of skid
control ECU and body ground.
OK: 10 - 14 V

OK

CHECK AND REPLACE SKID CONTROL ECU
ASSY

NG

2

CHECK HARNESS AND CONNECTOR(STEERING ANGLE SENSOR - SKID
CONTROL ECU ASSY)

(a)

Remove the steering wheel and column lower cover (See
page 

50-8

).

(b)

Disconnect the steering sensor connector.

(c)

Turn the ignition switch ON.

(d)

Measure voltage between terminal 1 and 2, 2 and 9 of the
steering sensor harness side connector.
OK: 10 - 14 V

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK