LEXUS LS430 2003 Factory Repair Manual

OK:
Needle indication is normal.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
2.READ VALUE OF HAND-HELD TESTER (ENGINE COOLANT)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
ENGINE:
DATA LIST REFERENCE
OK:
Coolant temperature displayed on the tester is between 80°C (176°F) and 95°C (203°F) after
warning up.
NG: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
OK: GO TO NEXT STEP
3.REPLACE COMBINATION METER ASSY
OK:
Normal operation
NG: GO TO ENGINE CONTROL SYSTEM (SEE REPLACEMENT
)
OK: END
WIRING DIAGRAM
ItemTest DetailsDiagnostic Note
COOLANT TEMPLOW /NORMAL /HI-
ItemMeasurement Item/ Range
(Display)Normal ConditionDiagnostic Note
COOLANT
TEMPCoolant Temperature / Min.: -
40°C (-40°F), Max.: 140°C
(284 °F)After warming up: 80
to 95°C (176 to 203°
F)If the value is "-40°C (-40°F)" or
"140°C (284°F)", sensor circuit is
open or shorted.

Fig. 65: Driver'S Seat Belt Warning Lamp Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
If there is an open in the ground circuit (Airbag sensor assy center), the airbag sensor assy center outputs DTCs.
Perform troubleshooting with the "Supplemental Restraint System" 05-1026.
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
METER:
ACTIVE TEST REFERENCE
OK:
Switch condition (ON/OFF) can be switched by ACTIVE TEST.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
ItemTest DetailsDiagnostic Note
D-BELT
REMINDIndicat. Lamp D-SEAT BELT
(OFF/ON)Confirm that the vehicle is stopped and engine
idling

2.READ VALUE OF HAND-HELD TESTER (DRIVER SEAT BELT)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
SRS AIRBAG:
Fig. 66: SRS Airbag Data List Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK:
Indicator lamp (ON/OFF) can be switched by actual operation.
NG: Go to step 3
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
3.INSPECT FRONT SEAT INNER BELT ASSY (DRIVER SIDE)
a. Disconnect the connector from the front seat inner belt assy (Driver Side).
b. Measure the resistance according to the value (s) in the table below.
Standard
RESISTANCE SPECIFICATIONS
NG: REPLACE FRONT SEAT INNER BELT ASSY (DRIVER SIDE)
Terminal NoConditionSpecified condition
B4-2 - B4-5Seat belt is fastenedApprox. 330 ohms
B4-2 - B4-5Seat belt is unfastenedApprox. 1,330 ohms

Fig. 67: Identifying Front Seat Inner Belt Assy (Driver Side) Connector Front View
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO NEXT STEP
4.CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT ASSY - BODY
GROUND) (SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
a. Disconnect the connector from the front seat inner belt assy (Driver Side).
b. Measure the resistance according to the value (s) in the table below.
Standard
RESISTANCE SPECIFICATIONS
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester ConnectionConditionSpecified Condition
B4-5 - Body groundAlwaysBelow 1 ohms

Fig. 68: Identifying Front Seat Inner Belt Assy (Driver Side) Connector Wire Harness View
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO NEXT STEP
5.CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT ASSY - DRIVER SIDE
JUNCTION BLOCK) (SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
a. Disconnect the B4, A23 connectors.
b. Measure the resistance according to the value (s) in the table below.
Standard
B4 AND A23 CONNECTORS RESISTANCE SPECIFICATIONS
Tester ConnectionConditionSpecified Condition
B4-2 - A23-10AlwaysBelow 1 ohms
A23-10 - Body groundAlways10 kohms or higher

Fig. 69: Identifying B4 And A23 Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIRBAG SENSOR ASSY CENTER (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
WIRING DIAGRAM
Fig. 70: Passenger'S Seat Belt Warning Lamp Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
Displa
y except for the seat belt warning indicator are shown in the navigation system (see HOW TO

PROCEED WITH TROUBLESHOOTING) and A/C system (see HOW TO PROCEED WITH
TROUBLESHOOTING ).
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
Standard
ACTIVE TEST REFERENCE
OK:
Indicator lamp (ON/OFF) can be switched by ACTIVE TEST.
NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
OK: GO TO NEXT STEP
2.READ VALUE OF HAND-HELD TESTER (FRONT PASSENGER SEAT BELT)
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
SRS AIRBAG:
DATA LIST ITEM REFERENCE
OK:
Switch condition (ON/OFF) can be switched by actual operation.
RESULT:
RESULT REFERENCE
B: Go to step 6
ItemTest DetailsDiagnostic Note
P-BELT
REMINDIndicat. Lamp P-SEAT BELT
(OFF/ON)Confirm that the vehicle is stopped and engine
idling
ItemMeasurement Item/ Range
(Display)Normal ConditionDiagnostic
Note
P SEAT
BUCKLPassenger seat belt buckle switch
is ON /OFFON: Seat belt is fastened OFF: Seat
belt is unfastened-
NGA
OK (w/o LEXUS Navigation)B
K (w/ LEXUS Navigation)C

C: Go to step 9
A: GO TO NEXT STEP
3.INSPECT FRONT SEAT INNER BELT ASSY (PASSENGER SIDE)
a. Disconnect the connector from the front seat inner belt assy (FR Passenger Side).
b. Measure the resistance according to the value (s) in the table below.
Standard
RESISTANCE SPECIFICATIONS
NG: REPLACE FRONT SEAT INNER BELT ASSY (PASSENGER SIDE)
Fig. 71: Identifying Front Seat Inner Belt Assy (Passenger Side) Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO NEXT STEP
Terminal NoConditionSpecified condition
B5-2 - B5-5Seat belt is fastenedApprox. 330 ohms
B5-2 - B5-5Seat belt is unfastenedApprox. 1,330 ohms

4.CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT ASSY - BODY
GROUND) (SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
a. Disconnect the connector from the front seat inner belt assy (FR Passenger Side).
b. Measure the resistance according to the value (s) in the table below.
Standard
RESISTANCE SPECIFICATIONS
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Fig. 72: Identifying Front Seat Inner Belt Assy (Passenger Side) Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO NEXT STEP
5.CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT ASSY - AIRBAG
SENSOR ASSY CENTER) (SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
Tester ConnectionConditionSpecified Condition
B5-5 - Body groundAlwaysBelow 1 ohms