Combination LEXUS LS430 2003 Factory Manual PDF

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

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

Fig. 73: Identifying B5 And A25 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 )
6.INSPECT COMBINATION METER ASSY
a. Disconnect the clock assy connector.
b. Measure the voltage according to the value (s) in the table below.
Standard
VOLTAGE SPECIFICATIONS
NG: Go to step 8
Fig. 74: Identifying C12 Connector Terminals
Terminal NoConditionSpecified condition
C12-9 - Body groundIgnition switch ON, Passenger seat belt is unfastened10 to 14 V

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE CLOCK ASSY
8.CHECK HARNESS AND CONNECTOR (CLOCK ASSY - COMBINATION METER ASSY)
(SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
a. Disconnect the C10 and C12 connectors.
b. Measure the resistance according to the value (s) in the table below.
Standard
C10 AND C12 CONNECTORS RESISTANCE SPECIFICATIONS
Tester ConnectionConditionSpecified Condition
C12-9 - C10-7AlwaysBelow 1 ohms
C12-9 - Body groundAlways10 kohms or higher

Fig. 76: Identifying C10 And C12 Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
9.INSPECT COMBINATION METER ASSY
a. Disconnect the combination meter connectors.
b. Measure the voltage according to the value (s) in the table below.
Standard
COMBINATION METER CONNECTOR TERMINALS VOLTAGE SPECIFICATIONS
NG: Go to step 11
Fig. 77: Identifying Combination Meter Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Terminal NoConditionSpecified condition
C12-9 - Body groundIgnition switch ON, Passenger seat belt is unfastened10 to 14 V

OK: REPLACE MULTI-DISPLAY
11.CHECK HARNESS AND CONNECTOR (MULTI-DISPLAY - COMBINATION METER ASSY)
(SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
a. Disconnect the M4 and C12 connectors.
b. Measure the resistance according to the value (s) in the table below.
Standard
M4 AND C12 CONNECTORS RESISTANCE SPECIFICATIONS
Tester ConnectionConditionSpecified Condition
C12-9 - M4-21AlwaysBelow 1 ohms
C12-9 - Body groundAlways10 kohms or higher

Fig. 79: Identifying M4 And C12 Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
WIRING DIAGRAM
Fig. 80: ODO/TRIP Switch Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE OF HAND-HELD TESTER
a. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
METER:
DATA LIST REFERENCE
ItemMeasurement Item/ Range (Display)Normal ConditionDiagnostic Note
ODO/TRIP SWODO/TRIP switch is ON / OFFON: Switch is pushed
OFF: Switch is released-
TRIP RESET SWTRIP RESET switch is ON / OFFON: Switch is pushed
OFF: Switch is released-

OK:
Switch condition (ON/OFF) can be switched by actual operation.
NG: Go to step 2
OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL
)
2.INSPECT TRIP SWITCH
a. Disconnect the trip switch connector.
b. Measure the resistance according to the value (s) in the table below.
Standard
TRIP SWITCH CONNECTOR RESISTANCE SPECIFICATIONS
NG: REPLACE TRIP SWITCH
Terminal NoConditionSpecified condition
T10-1 - T10-2ODO/TRIP switch OFF --> ON10 kohms or higher --> Below 1 ohms
T10-3 - T10-2RESET switch OFF --> ON10 kohms or higher --> Below 1 ohms

Fig. 81: Identifying Trip Switch Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: GO TO NEXT STEP
3.CHECK HARNESS AND CONNECTOR (TRIP SWITCH - COMBINATION METER ASSY)
(SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
a. Disconnect the C12 and T10 connectors.
b. Measure the resistance according to the value (s) in the table below.
Standard
C12 AND T10 CONNECTORS RESISTANCE SPECIFICATIONS
Tester ConnectionConditionSpecified Condition
C12-7 - T10-1AlwaysBelow 1 ohms
C12-8 - T10-3AlwaysBelow 1 ohms
C12-10 - T10-2AlwaysBelow 1 ohms
C12-7 - Body groundAlways10 kohms or higher
C12-8 - Body groundAlways10 kohms or higher
C12-10 - Body groundAlways10 kohms or higher