Lexus ES300 (2002 year). Service manual - part 308

F41241

ECU-IG

GND4

F40456

GND1

GND2

GND3

IG1

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-351

504

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

INSPECTION PROCEDURE

1

INSPECT FUSE(ECU-IG OF DRIVER SIDE J/B)

(a)

Remove ECU-IG fuse from the driver side J/B.

(b)

Check continuity of ECU-IG fuse.
OK: Continuity

NG

INSPECT FOR SHORT CIRCUIT IN ALL
HARNESS AND COMPONENTS CONNECTED
TO ECU-IG FUSE

OK

2

INSPECT BATTERY(TERMINAL VOLTAGE)

(a)

Check the battery positive voltage.
OK: 10 - 14 V

NG

CHECK CHARGING SYSTEM
(See page 

19-1 1

)

OK

3

CHECK VOLTAGE OF ECU IG POWER SOURCE

IN CASE OF USING THE HAND-HELD TESTER:
(a)

Select the item ”IG VOLTAGE” in the DATA LIST and red its value displayed on the hand-held tester.

(b)

Check the voltage condition output from the ECU displayed on the hand-held tester.
OK: ”Normal” is displayed.

IN CASE OF NOT USING THE HAND-HELD TESTER:
(a)

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

(b)

Turn the ignition switch ON, measure voltage between
terminals IG1 and GND of skid control ECU connector.
OK: 10 - 14 V

OK

CHECK AND REPLACE SKID CONTROL ECU
ASSY

NG

05-352

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

505

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

4

CHECK CONTINUITY(SKID CONTROL ECU ASSY - BODY GROUND)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

CHECK AND REPAIR HARNESS AND CONNECTOR

F41986

Skid Control ECU

GL1

GL2

YAW

GYAW

YSS

W

B-Y

3

Passenger Side J/B

Battery

IA

FL MAIN

3B

6

4

2R

B-G

4

2

AM1

IG1

IG1

VYS

GL1

GL2

YAW2

VYS

GYAW

5

1

2

2E

2L

2A

2A

8

2

2

8

2

1

8

5

Y

L

W

R

B

S6

S6

S6

S6

S6

S6

S7

1

1

1

2

ALT

Engine Room R/B

B-G

W-B

B-R

3B

ECU-IG

AM1

I14
Ignition SW

IG Relay

Driver Side J/B

21

22

10

1

20

3

7

W

68

27

W

(Shielded)

S6

16

YD

Y1 
Yaw Rate Sensor

G

6

YD

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

05-353

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2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

DTC

C1243/43 MALFUNCTION IN DECELERATION SENSOR

DTC

C1245/45 MALFUNCTION IN DECELERATION SENSOR

DTC

C1336/39 ZERO POINT CALIBRATION OF

DECELERATION SENSOR UNDONE

CIRCUIT DESCRIPTION

DTC No.

DTC Detecting Condition

Trouble Area

C1243/43

While vehicle speed gets to 0 km/h (0 mph) from 30 km/h (18
mph), and the condition that GL1 and GL2 signals of ECU
terminals did not change 2 LSB or more continued in a 
sequence 16 times.

Deceleration sensor

C1245/45

At the vehicle speed of 30 km/h (18 mph) or more, and the
condition that the difference between acceleration and decel-
eration values of computation from deceleration sensor and
vehicle speed becomes more than 0.35 G continues for 60
sec. or more.

Deceleration sensor

Wire harness for deceleration sensor system

C1336/39

At the initial time after replacing the computer, or after erasing
the deceleration sensor memory by operating the terminals Ts
and CG of DLC3, the ignition is turned ON and the vehicle is
driven in any mode except for the test mode.

Deceleration sensor

Deceleration sensor circuit

Zero point calibration not done

WIRING DIAGRAM

055W1-02

05-354

-

DIAGNOSTICS

ABS WITH EBD & BA & TRAC & VSC SYSTEM

507

2002 LEXUS ES300 REPAIR MANUAL   (RM911U)

INSPECTION PROCEDURE

HINT:
After step 1 and 2, go to step 3 in case of using the hand-held tester, and go to step 5 in case of not using
the hand-held tester.

1

PERFORM DECELERATION SENSOR ZERO POINT CALIBRATION
(See page 

05-239

)

2

RECONFIRM DTC(See page 

05-288

)

A

Malfunction Code

B

Normal Code

B

END

A

3

READ VALUE OF HAND-HELD TESTER(DECELERATION SENSOR OUTPUT
VALUE)

(a)

Select the item ”DECELERAT SEN, DECELERAT SEN2” in the DATA LIST and read its value dis-
played on the hand-held tester.

(b)

Check that the deceleration value of the deceleration sensor observed in the hand-held tester is
changing when the vehicle is tilted.
OK:
Deceleration value must be changing.

OK

CHECK AND REPLACE SKID CONTROL ECU
ASSY

NG

4

CHECK HARNESS AND CONNECTOR(YAW RATE SENSOR(DECELERATION
SENSOR) - SKID CONTROL ECU ASSY)(See page 

01-31

)

NG

REPAIR OR REPLACE HARNESS OR
CONNECTOR

OK

REPLACE YAWRATE SENSOR