Toyota 4Runner: Rear Airbag Sensor Assembly RH Initialization Incomplete (B1633/81,B1638/82)

DESCRIPTION

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, side airbag sensor LH or RH and rear airbag sensor LH or RH.

The 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 B1633 or B1638 is stored when a malfunction is detected in the circuit for the rear collision sensor LH or RH (to determine deployment of the curtain shield airbag LH or RH).

DTC Code	DTC Detection Condition	Trouble Area
B1633/81	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 rear collision sensor RH (to determine deployment of the curtain shield airbag RH) for 2 seconds. A rear airbag sensor RH malfunction. A side airbag sensor RH malfunction. A center airbag sensor malfunction.	Floor wire Rear airbag sensor RH Side airbag sensor assembly RH Center airbag sensor assembly
B1638/82	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 rear collision sensor LH (to determine deployment of the curtain shield airbag LH) for 2 seconds. A rear airbag sensor LH malfunction. A side airbag sensor LH malfunction. A center airbag sensor malfunction.	No. 2 floor wire Rear airbag sensor LH Side airbag sensor assembly LH Center airbag sensor assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected (See page ).

PROCEDURE

1.	CHECK FOR DTC

(a) Turn the ignition switch off.

HINT:

If a communication error occurs, DTCs for both the LH and RH sides will be stored simultaneously. The malfunctioning area can be identified by turning the ignition switch off and then to ON again.

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

(c) Check for DTCs (See page ).

Result

Result	Proceed to
DTC B1633 and B1638 are not output	A
DTC B1638 is output	B
DTC B1633 is output	C

HINT:

Codes other than DTC B1633 and B1638 may be output at this time, but they are not related to this check.

A

USE SIMULATION METHOD TO CHECK

B

GO TO STEP 7

C

2.	CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition switch off.

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

(c) Check that the connectors are properly connected to the center airbag sensor and rear airbag sensor RH.

OK:

The connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY

OK

3.	CHECK CONNECTORS

(a) Disconnect the connectors from the center airbag sensor and rear airbag sensor RH.

(b) 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

NG

REPLACE FLOOR WIRE

OK

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

(a) 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)

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
N9-4 (BBR+) - Body ground	Ignition switch ON	Below 1 V
N9-3 (BBR-) - Body ground	Ignition switch ON	Below 1 V

(c) Turn the ignition switch off.

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

(e) Using a service wire, connect terminals 17 (BBR+) and 18 (BBR-) of connector B.

NOTICE:

Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N9-4 (BBR+) - N9-3 (BBR-)	Always	Below 1 Ω

(g) Disconnect the service wire from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N9-4 (BBR+) - N9-3 (BBR-)	Always	1 MΩ or higher
N9-4 (BBR+) - Body ground	Always	1 MΩ or higher
N9-3 (BBR-) - Body ground	Always	1 MΩ or higher

NG

REPLACE FLOOR WIRE

OK

5.	CHECK REAR AIRBAG SENSOR RH

(a) Connect the connector to the center airbag sensor.

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

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

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

(e) Clear the DTCs stored in memory (See page
).

(f) Turn the ignition switch off.

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

(h) Check for DTCs (See page ).

Result

Result	Proceed to
DTC B1633 and B1638 are not output	A
DTC B1638 is output	B
DTC B1633 is output	C

HINT:

Codes other than DTC B1633 and B1638 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

(i) Turn the ignition switch off.

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

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

A

USE SIMULATION METHOD TO CHECK

B

REPLACE REAR AIRBAG SENSOR RH

C

6.	CHECK SIDE AIRBAG SENSOR RH

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

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

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

(d) Clear the DTCs stored in memory (See page
).

(e) Turn the ignition switch off.

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

(g) Check for DTCs (See page ).

Result

Result	Proceed to
DTC B1633 and B1638 are not output	A
DTC B1638 is output	B
DTC B1633 is output	C

HINT:

Codes other than DTC B1633 and B1638 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

(h) Turn the ignition switch off.

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

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

C

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

A

USE SIMULATION METHOD TO CHECK

B

REPLACE SIDE AIRBAG SENSOR ASSEMBLY RH

7.	CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition switch off.

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

(c) Check that the connectors are properly connected to the center airbag sensor and rear airbag sensor LH.

OK:

The connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY

OK

8.	CHECK CONNECTORS

(a) Disconnect the connectors from the center airbag sensor and rear airbag sensor LH.

(b) 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

NG

REPLACE NO. 2 FLOOR WIRE

OK

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

(a) 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)

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
O8-4 (BBL+) - Body ground	Ignition switch ON	Below 1 V
O8-3 (BBL-) - Body ground	Ignition switch ON	Below 1 V

(c) Turn the ignition switch off.

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

(e) Using a service wire, connect terminals 24 (BBL+) and 23 (BBL-) of connector B.

NOTICE:

Do not forcibly insert the service wire into the terminals of the connector when connecting a service wire.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O8-4 (BBL+) - O8-3 (BBL-)	Always	Below 1 Ω

(g) Disconnect the service wire from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O8-4 (BBL+) - O8-3 (BBL-)	Always	1 MΩ or higher
O8-4 (BBL+) - Body ground	Always	1 MΩ or higher
O8-3 (BBL-) - Body ground	Always	1 MΩ or higher

NG

REPLACE NO. 2 FLOOR WIRE

OK

10.	CHECK REAR AIRBAG SENSOR LH

(a) Connect the connector to the center airbag sensor.

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

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

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

(e) Clear the DTCs stored in memory (See page
).

(f) Turn the ignition switch off.

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

(h) Check for DTCs (See page ).

Result

Result	Proceed to
DTC B1633 and B1638 are not output	A
DTC B1633 is output	B
DTC B1638 is output	C

HINT:

Codes other than DTC B1633 and B1638 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

(i) Turn the ignition switch off.

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

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

A

USE SIMULATION METHOD TO CHECK

B

REPLACE REAR AIRBAG SENSOR LH

C

11.	CHECK SIDE AIRBAG SENSOR LH

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

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

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

(d) Clear the DTCs stored in memory (See page
).

(e) Turn the ignition switch off.

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

(g) Check for DTCs (See page ).

Result

Result	Proceed to
DTC B1633 and B1638 are not output	A
DTC B1633 is output	B
DTC B1638 is output	C

HINT:

Codes other than DTC B1633 and B1638 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

(h) Turn the ignition switch off.

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

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

C

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

A

USE SIMULATION METHOD TO CHECK

B

REPLACE SIDE AIRBAG SENSOR ASSEMBLY LH