Seat Belt. Seat Belt Warning System Driver Side Seat Belt Warning Light Does Not Operate

When the ignition switch ON, the center airbag sensor assembly*1 (main body ECU [cowl side junction block LH]*2) transmits front seat inner belt state signals to the combination meter assembly through the CAN. If the driver seat belt is not fastened, the combination meter assembly blinks the driver side seat belt warning light. If the seat belt is fastened, the warning light goes off.

*1: w/ Airbag System
*2: w/o Airbag System

WIRING DIAGRAM

Land Cruiser. Urj200, 202 Grj200 Vdj200.Seat Belt.Seat Belt Tension Reducer System.Seat Belt Warning System Driver Side Seat Belt Warning Light Does Not Operate

INSPECTION PROCEDURE

1.CHECK VEHICLE TYPE

Check vehicle type.
Result
Result
Proceed to
w/ Airbag System
A
w/o Airbag System
B

Go to step 7

A

2.CHECK FOR DTC

Check for DTCs.
Result
Result
Proceed to
DTC is not output
A
CAN system DTC is output (for LHD)
B
CAN system DTC is output (for RHD)
C
Airbag system DTC is output
D

Go to CAN COMMUNICATION SYSTEM (Click here)

Go to AIRBAG SYSTEM (Click here)

A

3.READ VALUE USING INTELLIGENT TESTER (DRIVER SIDE BUCKLE SWITCH)

Check the Data List for proper functioning of the driver side seat belt buckle switch.

SRS Airbag
Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Driver Buckle SW	Driver side seat belt / Set, Unset or NG	Set: Driver side seat belt is fastened Unset: Driver side seat belt is unfastened	NG: Data is not determined

Result
Result	Proceed to
Set or Unset is displayed on the tester screen according to the driver side seat belt condition	A
Set or Unset is not displayed normally on the tester screen according to the driver side seat belt condition	B
NG is displayed on the tester screen	C

REPLACE FRONT SEAT INNER BELT ASSEMBLY (for Driver Side) (Click here)

REPLACE CENTER AIRBAG SENSOR ASSEMBLY (Click here)

A

4.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DRIVER SIDE SEAT BELT WARNING LIGHT)

Operate the intelligent tester according to the display and select Active Test.

Combination Meter
Item
Test Part
Control Range
Diagnostic Note
Driver Side Seat Belt
Driver side seat belt warning light
ON/OFF
Confirm that the vehicle is stopped and the engine is idling.
OK:
Driver side seat belt warning light condition can be switched by Active Test.

Combination Meter
Item	Test Part	Control Range	Diagnostic Note
Driver Side Seat Belt	Driver side seat belt warning light	ON/OFF	Confirm that the vehicle is stopped and the engine is idling.

Result
Result	Proceed to
OK	A
NG (w/ Multi-information Display)	B
NG (w/o Multi-information Display)	C

REPLACE COMBINATION METER (Click here)

A

5.REPLACE CENTER AIRBAG SENSOR ASSEMBLY

Temporarily replace the center airbag sensor assembly with a new one (Click here).

NEXT

6.CHECK DRIVER SIDE SEAT BELT WARNING LIGHT

Check the driver side seat belt warning light function (Click here).
OK:
Driver side seat belt warning light operates normally.
Result
Result
Proceed to
OK
A
NG (w/ Multi-information Display)
B
NG (w/o Multi-information Display)
C

REPLACE COMBINATION METER ASSEMBLY (Click here)

END (CENTER AIRBAG SENSOR ASSEMBLY IS DEFECTIVE)

7.CHECK FOR DTC

Check for DTCs.

Result
Result	Proceed to
DTC is not output	A
CAN system DTC is output (for LHD)	B
CAN system DTC is output (for RHD)	C

Go to CAN COMMUNICATION SYSTEM (Click here)

A

8.READ VALUE USING INTELLIGENT TESTER (DRIVER SIDE BUCKLE SWITCH)

Check the Data List for proper functioning of the driver side seat belt buckle switch.

Main Body
Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
D Seat Buckle SW	Driver side seat belt / ON or OFF	ON: Driver side seat belt is fastened OFF: Driver side seat belt is unfastened	-

OK:: The display is as specified in the normal condition column.

Go to step 10

OK

9.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DRIVER SIDE SEAT BELT WARNING LIGHT)

Operate the intelligent tester according to the steps on the display and select Active Test.

Combination Meter
Item
Test Part
Control Range
Diagnostic Note
Driver Side Seat Belt
Driver side seat belt warning light
ON/OFF
Confirm that the vehicle is stopped and the engine is idling.
OK:
Driver side seat belt warning light condition can be switched by Active Test.

REPLACE COMBINATION METER ASSEMBLY (Click here)

REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

10.INSPECT FRONT SEAT INNER BELT ASSEMBLY (for Driver Side)

Remove the front seat inner belt assembly (for Driver Side) (Click here).

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Switch Condition
Specified Condition
12 - 9
Seat belt unfastened (buckle switch is off)
Below 1 Ω
Seat belt fastened (buckle switch is on)
10 kΩ or higher

REPLACE FRONT SEAT INNER BELT ASSEMBLY (for Driver Side) (Click here)

OK

11.CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT - COMBINATION METER AND BODY GROUND)

Disconnect the K43*1 or L49*2 front seat inner belt assembly (for Driver Side) connector.
1. *1: for LHD
2. *2: for RHD

Disconnect the E1 main body ECU (cowl side junction block LH) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:
for LHD:
Tester Connection
Condition
Specified Condition
K43-12 - E1-7 (DBKL)
Always
Below 1 Ω
K43-12 or E1-7 (DBKL) - Body ground
Always
10 kΩ or higher
K43-9 - Body ground
Always
Below 1 Ω
for RHD:
Tester Connection
Condition
Specified Condition
L49-12 - E1-7 (DBKL)
Always
Below 1 Ω
L49-12 or E1-7 (DBKL) - Body ground
Always
10 kΩ or higher
L49-9 - Body ground
Always
Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

Tester Connection	Switch Condition	Specified Condition
12 - 9	Seat belt unfastened (buckle switch is off)	Below 1 Ω
12 - 9	Seat belt fastened (buckle switch is on)	10 kΩ or higher

Tester Connection	Condition	Specified Condition
K43-12 - E1-7 (DBKL)	Always	Below 1 Ω
K43-12 or E1-7 (DBKL) - Body ground	Always	10 kΩ or higher
K43-9 - Body ground	Always	Below 1 Ω