Supplemental Restraint Systems. Dtc B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction

The seat belt buckle switch LH or RH circuit consists of the center airbag sensor and front seat inner belt LH or RH.
DTC B1655/37 is stored when a malfunction is detected in the seat belt buckle switch LH or RH circuit.

DTC Code	DTC Detection Condition	Trouble Area
B1655/37	One of the following conditions is met: The center airbag sensor detects a line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the seat belt buckle switch circuit for 2 seconds. A front seat inner belt malfunction. A center airbag sensor malfunction.	No. 2 floor wire Front seat inner belt assembly LH (Seat belt buckle switch LH) (for LHD) Front seat inner belt assembly RH (Seat belt buckle switch RH) (for RHD) Center airbag sensor assembly

WIRING DIAGRAM

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Supplemental Restraint Systems.Airbag System.
Dtc
B1655/37 Driver Side Seat Belt Buckle Switch Circuit Malfunction

INSPECTION PROCEDURE

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (LandCruiser RM000003YMD00TX.html).
When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).

1.CHECK VEHICLE TYPE

Check vehicle type.
Result
Result
Proceed to
for RHD
A
for LHD
B

Result
Result	Proceed to
for RHD	A
for LHD	B

Go to step 9

B

2.CHECK FOR DTC

Turn the ignition switch to ON.

Clear the DTCs (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
OK:
DTC B1655 is not output.
HINT:
Codes other than DTC B1655 may be output at this time, but they are not related to this check.

Go to step 3

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

3.CHECK CONNECTION OF CONNECTORS

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

Check that the connectors are properly connected to the center airbag sensor and front seat inner belt LH.
OK:
The connectors are properly connected.

CONNECT CONNECTORS PROPERLY

OK

4.CHECK CONNECTORS

Disconnect the connectors from the center airbag sensor and front seat inner belt LH.

Check that the connectors (on the center airbag sensor side and front seat inner belt LH side) are not damaged.
OK:
The connectors are not deformed or damaged.
Text in Illustration
*1
Front Seat Inner Belt LH
*2
Center Airbag Sensor

Text in Illustration
*1	Front Seat Inner Belt LH
*2	Center Airbag Sensor

REPLACE NO. 2 FLOOR WIRE

OK

5.CHECK NO. 2 FLOOR WIRE (CENTER AIRBAG SENSOR - FRONT SEAT INNER BELT LH)

Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

Text in Illustration
*1	Front Seat Inner Belt LH	*2	Center Airbag Sensor
*3	No. 2 Floor Wire	*4	Connector C
*5	Connector B	-	-
*a	Front view of wire harness connector (to Front Seat Inner Belt LH)	*b	Rear view of wire harness connector (to Center Airbag Sensor)

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
R48-2 (LBE+) - Body ground
Ignition switch ON
Below 1 V
R48-1 (LBE-) - Body ground
Ignition switch ON
Below 1 V

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
R48-2 (LBE+) - R1-11 (DBE+)	Always	Below 1 Ω
R48-1 (LBE-) - R1-12 (DBE-)	Always	Below 1 Ω
R48-2 (LBE+) - Body ground	Always	1 MΩ or higher
R48-1 (LBE-) - Body ground	Always	1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

OK

6.CHECK FRONT SEAT INNER BELT LH (SEAT BELT BUCKLE SWITCH)

Connect the connectors to the center airbag sensor and front seat inner belt LH.

Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Clear the DTCs (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
OK:
DTC B1655 is not output.
HINT:
Codes other than DTC B1655 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Front Seat Inner Belt LH
*2
Center Airbag Sensor

Text in Illustration
*1	Front Seat Inner Belt LH
*2	Center Airbag Sensor

Go to step 7

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

7.REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

Replace the front seat inner belt LH (LandCruiser RM000003RQO025X.html).
HINT:
Perform the inspection using parts from a normally functioning vehicle if possible.

NEXT

8.CHECK CENTER AIRBAG SENSOR

Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Clear the DTCs (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
OK:
DTC B1655 is not output.
HINT:
Codes other than DTC B1655 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Front Seat Inner Belt LH
*2
Center Airbag Sensor

Text in Illustration
*1	Front Seat Inner Belt LH
*2	Center Airbag Sensor

REPLACE CENTER AIRBAG SENSOR ASSEMBLY (LandCruiser RM000003YQB01BX.html)

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH (LandCruiser RM000003RQO025X.html)

9.CHECK FOR DTC

Turn the ignition switch to ON.

Clear the DTCs (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
OK:
DTC B1655 is not output.
HINT:
Codes other than DTC B1655 may be output at this time, but they are not related to this check.

Go to step 10

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

10.CHECK CONNECTION OF CONNECTORS

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

Check that the connectors are properly connected to the center airbag sensor and front seat inner belt RH.
OK:
The connectors are properly connected.

CONNECT CONNECTORS PROPERLY

OK

11.CHECK CONNECTORS

Disconnect the connectors from the center airbag sensor and front seat inner belt RH.

Check that the connectors (on the center airbag sensor side and front seat inner belt RH side) are not damaged.
OK:
The connectors are not deformed or damaged.
Text in Illustration
*1
Front Seat Inner Belt RH
*2
Center Airbag Sensor

REPLACE NO. 2 FLOOR WIRE

OK

12.CHECK NO. 2 FLOOR WIRE (CENTER AIRBAG SENSOR - FRONT SEAT INNER BELT RH)

Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

Text in Illustration
*1	Front Seat Inner Belt RH	*2	Center Airbag Sensor
*3	No. 2 Floor Wire	*4	Connector C
*5	Connector B	-	-
*a	Front view of wire harness connector (to Front Seat Inner Belt RH)	*b	Rear view of wire harness connector (to Center Airbag Sensor)

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
Q34-2 (RBE+) - Body ground
Ignition switch ON
Below 1 V
Q34-1 (RBE-) - Body ground
Ignition switch ON
Below 1 V

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Q34-2 (RBE+) - Q25-11 (DBE+)	Always	Below 1 Ω
Q34-1 (RBE-) - Q25-12 (DBE-)	Always	Below 1 Ω
Q34-2 (RBE+) - Body ground	Always	1 MΩ or higher
Q34-1 (RBE-) - Body ground	Always	1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

OK

13.CHECK FRONT SEAT INNER BELT RH (SEAT BELT BUCKLE SWITCH)

Connect the connectors to the center airbag sensor and front seat inner belt LH.

Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Clear the DTCs (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
OK:
DTC B1655 is not output.
HINT:
Codes other than DTC B1655 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Front Seat Inner Belt LH
*2
Center Airbag Sensor

Go to step 14

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

14.REPLACE FRONT SEAT INNER BELT ASSEMBLY RH

Turn the ignition switch off.

Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

Replace the front seat inner belt LH (LandCruiser RM000003RQO025X.html).
HINT:
Perform the inspection using parts from a normally functioning vehicle if possible.

NEXT

15.CHECK CENTER AIRBAG SENSOR

Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Clear the DTCs (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 60 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
OK:
DTC B1655 is not output.
HINT:
Codes other than DTC B1655 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Front Seat Inner Belt RH
*2
Center Airbag Sensor

REPLACE CENTER AIRBAG SENSOR ASSEMBLY (LandCruiser RM000003YQB01BX.html)

REPLACE FRONT SEAT INNER BELT ASSEMBLY RH (LandCruiser RM000003RQO025X.html)

Tester Connection	Switch Condition	Specified Condition
R48-2 (LBE+) - Body ground	Ignition switch ON	Below 1 V
R48-1 (LBE-) - Body ground	Ignition switch ON	Below 1 V