Supplemental Restraint Systems. Dtc B1642/81 Lost Communication With Side Satellite Sensor Bus Rh

The circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH) is composed of the center airbag sensor, rear airbag sensor LH or RH and side airbag sensor LH or RH.
The side airbag sensor LH or RH and rear airbag sensor LH or RH detect impacts to the vehicle and send signals to the center airbag sensor to determine if the airbag should be deployed.
DTC B1642/81 or B1647/82 is stored when a malfunction is detected in the circuit for the side collision sensor LH or RH (to determine deployment of the front seat side airbag LH or RH and curtain shield airbag LH or RH).

DTC Code	DTC Detection Condition	Trouble Area
B1642/81	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 circuit for the side collision sensor RH (to determine deployment of the front seat side airbag RH and curtain shield airbag RH) for 2 seconds. A side airbag sensor RH malfunction. A rear airbag sensor RH malfunction. A center airbag sensor malfunction.	Floor wire Front door wire RH Side airbag sensor assembly RH Rear airbag sensor RH Center airbag sensor assembly
B1647/82	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 circuit for the side collision sensor LH (to determine deployment of the front seat side airbag LH and curtain shield airbag LH) for 2 seconds. A side airbag sensor LH malfunction. A rear airbag sensor LH malfunction. A center airbag sensor malfunction.	No. 2 floor wire Front door wire LH Side airbag sensor assembly LH Rear airbag sensor LH 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
B1642/81 Lost Communication With Side Satellite Sensor Bus Rh

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 FOR DTC

Turn the ignition switch off.

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

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
Result
Result
Proceed to
DTC B1642 and B1647 are not output
A
DTC B1647 is output
B
DTC B1642 is output
C
HINT:
Codes other than DTC B1642 and B1647 may be output at this time, but they are not related to this check.

Result
Result	Proceed to
DTC B1642 and B1647 are not output	A
DTC B1647 is output	B
DTC B1642 is output	C

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

Go to step 11

C

2.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 rear airbag sensor RH.
OK:
The connectors are properly connected.

CONNECT CONNECTORS PROPERLY

OK

3.CHECK CONNECTORS

Disconnect the connectors from the center airbag sensor and rear airbag sensor RH.

Check that the connectors (on the center airbag sensor side and rear airbag sensor RH side) are not damaged.
OK:
The connectors are not deformed or damaged.
Text in Illustration
*1
Rear Airbag Sensor RH
*2
Center Airbag Sensor

Text in Illustration
*1	Rear Airbag Sensor RH
*2	Center Airbag Sensor

REPLACE FLOOR WIRE

OK

4.CHECK FLOOR WIRE (CENTER AIRBAG SENSOR - REAR AIRBAG SENSOR RH)

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

Text in Illustration
*1	Rear Airbag Sensor RH	*2	Center Airbag Sensor
*3	Floor Wire	*4	Connector C
*5	Connector B	*6	Service Wire
*a	Rear view of wire harness connector (to Rear Airbag Sensor 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
Q4-4 (BBR+) - Body ground
Ignition switch ON
Below 1 V
Q4-3 (BBR-) - 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.

Using a service wire, connect terminals 8 (BBR+) and 11 (BBR-) of connector B.
NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
Q4-4 (BBR+) - Q4-3 (BBR-)
Always
Below 1 Ω

Disconnect the service wire from connector B.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
Q4-4 (BBR+) - Q4-3 (BBR-)
Always
1 MΩ or higher
Q4-4 (BBR+) - Body ground
Always
1 MΩ or higher
Q4-3 (BBR-) - Body ground
Always
1 MΩ or higher

REPLACE FLOOR WIRE

OK

5.CHECK CONNECTION OF CONNECTOR

Check that the connector is properly connected to the side airbag sensor RH.
OK:
The connector is properly connected.

CONNECT CONNECTOR PROPERLY

OK

6.CHECK CONNECTORS

Disconnect the connector from the side airbag sensor RH.

Check that the connector (on the side airbag sensor RH side) is not damaged.
OK:
The connector is not deformed or damaged.
Text in Illustration
*1
Side Airbag Sensor RH
*2
Rear Airbag Sensor RH

Text in Illustration
*1	Side Airbag Sensor RH
*2	Rear Airbag Sensor RH

REPLACE HARNESS AND CONNECTOR

OK

7.CHECK SIDE AIRBAG SENSOR RH CIRCUIT

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

Text in Illustration
*1	Side Airbag Sensor RH	*2	Rear Airbag Sensor RH
*3	Connector E	*4	Connector B
*5	Service Wire	-	-
*a	Rear view of wire harness connector (to Side Airbag Sensor RH)	*b	Rear view of wire harness connector (to Rear Airbag Sensor RH)

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
Q4-1 (BCR+) - Body ground
Ignition switch ON
Below 1 V
Q4-2 (BCR-) - 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.

Using a service wire, connect terminals 2 (BCR+) and 1 (BCR-) of connector E.
NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
Q4-1 (BCR+) - Q4-2 (BCR-)
Always
Below 1 Ω

Disconnect the service wire from connector E.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
Q4-1 (BCR+) - Q4-2 (BCR-)
Always
1 MΩ or higher
Q4-1 (BCR+) - Body ground
Always
1 MΩ or higher
Q4-2 (BCR-) - Body ground
Always
1 MΩ or higher

Go to step 10

OK

8.CHECK REAR AIRBAG SENSOR RH

Connect the connectors to the center airbag sensor and side airbag sensor RH.

Interchange the rear airbag sensor LH with RH and connect the connectors to them.

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 stored in memory (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 90 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
Result
Result
Proceed to
DTC B1642 and B1647 are not output
A
DTC B1647 is output (for 3 Door)
B
DTC B1647 is output (for 5 Door)
C
DTC B1642 is output
D
HINT:
Codes other than DTC B1642 and B1647 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Rear Airbag Sensor LH
*2
Center Airbag Sensor

Turn the ignition switch off.

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

Return the rear airbag sensor LH and RH to their original positions and connect the connectors to them.

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

REPLACE REAR AIRBAG SENSOR RH (for 3 Door) (LandCruiser RM000003YQN01LX.html)

REPLACE REAR AIRBAG SENSOR RH (for 5 Door) (LandCruiser RM000003YQN01KX.html)

D

9.CHECK SIDE AIRBAG SENSOR RH

Interchange the side airbag sensor RH with LH and connect the connectors to them.

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 stored in memory (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 90 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
Result
Result
Proceed to
DTC B1642 and B1647 are not output
A
DTC B1647 is output
B
DTC B1642 is output
C
HINT:
Codes other than DTC B1642 and B1647 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Side Airbag Sensor LH
*2
Rear Airbag Sensor RH

Turn the ignition switch off.

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

Return the side airbag sensor RH and LH to their original positions and connect the connectors to them.

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

REPLACE SIDE AIRBAG SENSOR ASSEMBLY RH (LandCruiser RM000003YQJ019X.html)

REPLACE CENTER AIRBAG SENSOR ASSEMBLY (LandCruiser RM000003YQB01BX.html)

10.CHECK FLOOR WIRE (REAR AIRBAG SENSOR RH - FRONT DOOR WIRE RH)

Disconnect the floor wire connector from the front door wire RH.

Text in Illustration
*1	Side Airbag Sensor RH	*2	Rear Airbag Sensor RH
*3	Front Door Wire RH	*4	Floor Wire
*5	Connector C	*6	Connector B
*7	Service Wire	-	-
*a	Front view of wire harness connector (to Front Door Wire RH)	*b	Rear view of wire harness connector (to Rear Airbag Sensor RH)

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

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
Q4-1 (BCR+) - Body ground
Ignition switch ON
Below 1 V
Q4-2 (BCR-) - 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.

Using a service wire, connect terminals 1 (BCR+) and 2 (BCR-) of connector C.
NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
Q4-1 (BCR+) - Q4-2 (BCR-)
Always
Below 1 Ω

Disconnect the service wire from connector C.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
Q4-1 (BCR+) - Q4-2 (BCR-)
Always
1 MΩ or higher
Q4-1 (BCR+) - Body ground
Always
1 MΩ or higher
Q4-2 (BCR-) - Body ground
Always
1 MΩ or higher

REPLACE FLOOR WIRE

REPLACE FRONT DOOR WIRE RH

11.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 rear airbag sensor LH.
OK:
The connectors are properly connected.

CONNECT CONNECTORS PROPERLY

OK

12.CHECK CONNECTORS

Disconnect the connectors from the center airbag sensor and rear airbag sensor LH.

Check that the connectors (on the center airbag sensor side and rear airbag sensor LH side) are not damaged.
OK:
The connectors are not deformed or damaged.
Text in Illustration
*1
Rear Airbag Sensor LH
*2
Center Airbag Sensor

REPLACE NO. 2 FLOOR WIRE

OK

13.CHECK NO. 2 FLOOR WIRE (CENTER AIRBAG SENSOR - REAR AIRBAG SENSOR LH)

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

Text in Illustration
*1	Rear Airbag Sensor LH	*2	Center Airbag Sensor
*3	No. 2 Floor Wire	*4	Connector C
*5	Connector B	*6	Service Wire
*a	Rear view of wire harness connector (to Rear Airbag Sensor 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
R4-4 (BBL+) - Body ground
Ignition switch ON
Below 1 V
R4-3 (BBL-) - 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.

Using a service wire, connect terminals 8 (BBL+) and 15 (BBL-) of connector B.
NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
R4-4 (BBL+) - R4-3 (BBL-)
Always
Below 1 Ω

Disconnect the service wire from connector B.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
R4-4 (BBL+) - R4-3 (BBL-)
Always
1 MΩ or higher
R4-4 (BBL+) - Body ground
Always
1 MΩ or higher
R4-3 (BBL-) - Body ground
Always
1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

OK

14.CHECK CONNECTION OF CONNECTOR

Check that the connector is properly connected to the side airbag sensor LH.
OK:
The connector is properly connected.

CONNECT CONNECTOR PROPERLY

OK

15.CHECK CONNECTORS

Disconnect the connector from the side airbag sensor LH.

Check that the connector (on the side airbag sensor LH side) is not damaged.
OK:
The connector is not deformed or damaged.
Text in Illustration
*1
Side Airbag Sensor LH
*2
Rear Airbag Sensor LH

REPLACE HARNESS AND CONNECTOR

OK

16.CHECK SIDE AIRBAG SENSOR LH CIRCUIT

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

Text in Illustration
*1	Side Airbag Sensor LH	*2	Rear Airbag Sensor LH
*3	Connector E	*4	Connector B
*5	Service Wire	-	-
*a	Rear view of wire harness connector (to Side Airbag Sensor LH)	*b	Rear view of wire harness connector (to Rear Airbag Sensor LH)

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
R4-1 (BCL+) - Body ground
Ignition switch ON
Below 1 V
R4-2 (BCL-) - 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.

Using a service wire, connect terminals 2 (BCL+) and 1 (BCL-) of connector E.
NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
R4-1 (BCL+) - R4-2 (BCL-)
Always
Below 1 Ω

Disconnect the service wire from connector E.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
R4-1 (BCL+) - R4-2 (BCL-)
Always
1 MΩ or higher
R4-1 (BCL+) - Body ground
Always
1 MΩ or higher
R4-2 (BCL-) - Body ground
Always
1 MΩ or higher

Go to step 19

OK

17.CHECK REAR AIRBAG SENSOR LH

Connect the connectors to the center airbag sensor and side airbag sensor LH.

Interchange the rear airbag sensor LH with RH and connect the connectors to them.

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 stored in memory (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 90 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
Result
Result
Proceed to
DTC B1642 and B1647 are not output
A
DTC B1642 is output (for 3 Door)
B
DTC B1642 is output (for 5 Door)
C
DTC B1647 is output
D
HINT:
Codes other than DTC B1642 and B1647 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Rear Airbag Sensor RH
*2
Center Airbag Sensor

Turn the ignition switch off.

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

Return the rear airbag sensor LH and RH to their original positions and connect the connectors to them.

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

REPLACE REAR AIRBAG SENSOR LH (for 3 Door) (LandCruiser RM000003YQN01LX.html)

REPLACE REAR AIRBAG SENSOR LH (for 5 Door) (LandCruiser RM000003YQN01KX.html)

D

18.CHECK SIDE AIRBAG SENSOR LH

Interchange the side airbag sensor RH with LH and connect the connectors to them.

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 stored in memory (LandCruiser RM000000XFE0NGX.html).

Turn the ignition switch off.

Turn the ignition switch to ON, and wait for at least 90 seconds.

Check for DTCs (LandCruiser RM000000XFE0NGX.html).
Result
Result
Proceed to
DTC B1642 and B1647 are not output
A
DTC B1642 is output
B
DTC B1647 is output
C
HINT:
Codes other than DTC B1642 and B1647 may be output at this time, but they are not related to this check.
Text in Illustration
*1
Side Airbag Sensor RH
*2
Rear Airbag Sensor LH

Turn the ignition switch off.

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

Return the side airbag sensor RH and LH to their original positions and connect the connectors to them.

USE SIMULATION METHOD TO CHECK (LandCruiser RM000000XFD0N3X.html)

REPLACE SIDE AIRBAG SENSOR ASSEMBLY LH (LandCruiser RM000003YQJ019X.html)

REPLACE CENTER AIRBAG SENSOR ASSEMBLY (LandCruiser RM000003YQB01BX.html)

19.CHECK NO. 2 FLOOR WIRE (REAR AIRBAG SENSOR LH - FRONT DOOR WIRE LH)

Disconnect the No. 2 floor wire connector from the front door wire LH.

Text in Illustration
*1	Side Airbag Sensor LH	*2	Rear Airbag Sensor LH
*3	Front Door Wire LH	*4	No. 2 Floor Wire
*5	Connector C	*6	Connector B
*7	Service Wire	-	-
*a	Front view of wire harness connector (to Front Door Wire LH)	*b	Rear view of wire harness connector (to Rear Airbag Sensor LH)

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

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
R4-1 (BCL+) - Body ground
Ignition switch ON
Below 1 V
R4-2 (BCL-) - 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.

Using a service wire, connect terminals 2 (BCL+) and 1 (BCL-) of connector C.
NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
R4-1 (BCL+) - R4-2 (BCL-)
Always
Below 1 Ω

Disconnect the service wire from connector C.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
R4-1 (BCL+) - R4-2 (BCL-)
Always
1 MΩ or higher
R4-1 (BCL+) - Body ground
Always
1 MΩ or higher
R4-2 (BCL-) - Body ground
Always
1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

REPLACE FRONT DOOR WIRE LH

Tester Connection	Switch Condition	Specified Condition
Q4-4 (BBR+) - Body ground	Ignition switch ON	Below 1 V
Q4-3 (BBR-) - Body ground	Ignition switch ON	Below 1 V

Tester Connection	Condition	Specified Condition
Q4-4 (BBR+) - Q4-3 (BBR-)	Always	Below 1 Ω