Toyota Tacoma (2015-2018) Service Manual: Side Airbag Sensor RH Circuit Malfunction (B1620/21)

DESCRIPTION

The side airbag sensor assembly RH consists of parts such as the safing sensor, the diagnostic circuit and the lateral deceleration sensor.

When the airbag sensor assembly receives signals from the lateral deceleration sensor, it determines whether or not the SRS should be activated.

DTC B1620/21 is set when a malfunction is detected in the side airbag sensor assembly RH and rear airbag sensor RH circuit.

DTC No.	DTC Detecting Conditions	Trouble Areas
B1620/21	The airbag sensor assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the side airbag sensor assembly RH and rear airbag sensor RH circuit for 2 seconds Side airbag sensor assembly RH malfunction Rear airbag sensor RH malfunction Airbag sensor assembly malfunction	Side airbag sensor assembly RH Rear airbag sensor RH Airbag sensor assembly Floor wire

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work (See page ).

PROCEDURE

1.	CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition switch off.

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

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

OK:

The connectors are properly connected.

NG

CONNECT CONNECTORS

OK

2.	CHECK CONNECTORS

(a) Check that the connectors (on the airbag sensor assembly side and side airbag sensor assembly RH side) are not damaged (See page ).

OK:

The connectors are not deformed or damaged.

NG

REPLACE WIRE HARNESS

OK

3.	CHECK FLOOR WIRE (FOR OPEN)

(a) Disconnect the connectors from the airbag sensor assembly and the side airbag sensor assembly RH.

(b) Using service wire, connect S12-4 (BBR+) and S12-3 (BBR-) of connector C.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A23-8 (BBR+) - A23-11 (BBR-)	Always	Below 1 Ω

Text in Illustration

*1	Side Airbag Sensor Assembly RH
*2	Floor Wire
*3	Airbag Sensor Assembly
*4	Service Wire

NG

REPLACE FLOOR WIRE

OK

4.	CHECK FLOOR WIRE (FOR SHORT)

(a) Disconnect the service wire from connector C.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A23-8 (BBR+) - A23-11 (BBR-)	Always	1 MΩ or Higher

Text in Illustration

*1	Side Airbag Sensor Assembly RH
*2	Floor Wire
*3	Airbag Sensor Assembly

NG

REPLACE FLOOR WIRE

OK

5.	CHECK FLOOR WIRE (TO B+)

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

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A23-8 (BBR+) - Body ground	Ignition switch ON	Below 1 V
A23-11 (BBR-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Side Airbag Sensor Assembly RH
*2	Floor Wire
*3	Airbag Sensor Assembly

NG

REPLACE FLOOR WIRE

OK

6.	CHECK FLOOR WIRE (TO GROUND)

(a) Turn the ignition switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A23-8 (BBR+) - Body ground	Always	1 MΩ or Higher
A23-11 (BBR-) - Body ground	Always	1 MΩ or Higher

Text in Illustration

*1	Side Airbag Sensor Assembly RH
*2	Floor Wire
*3	Airbag Sensor Assembly

NG

REPLACE FLOOR WIRE

OK

7.	CHECK SIDE AIRBAG SENSOR ASSEMBLY RH

(a) Connect the connectors to the airbag sensor assembly.

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

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

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

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

(f) Turn the ignition switch off.

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

(h) Check for DTCs (See page ).

Result

Result	Proceed to
DTC B1620/21 is output.	A
DTC B1625/22 is output.	B
Neither DTC B1620/21 nor B1625/22 is output.	C

B

REPLACE REAR AIRBAG SENSOR RH

C

USE SIMULATION METHOD TO CHECK

A

8.	CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition switch off.

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

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

OK:

The connectors are properly connected.

NG

CONNECT CONNECTORS

OK

9.	CHECK CONNECTORS

(a) Check that the connectors (on the side airbag sensor assembly RH side and rear airbag sensor RH side) are not damaged (See page ).

OK:

The connectors are not deformed or damaged.

NG

REPLACE WIRE HARNESS

OK

10.	CHECK FLOOR WIRE (FOR OPEN)

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

(b) Using service wire, connect S14-1 (BCR-) and S14-2 (BCR+) of connector C.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
S12-1 (BCR+) - S12-2 (BCR-)	Always	Below 1 Ω

Text in Illustration

*1	Rear Airbag Sensor RH
*2	Side Airbag Sensor Assembly RH
*3	Service Wire

NG

REPLACE FLOOR WIRE

OK

11.	CHECK FLOOR WIRE (FOR SHORT)

(a) Disconnect the service wire from connector C.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
S12-1 (BCR+) - S12-2 (BCR-)	Always	1 MΩ or Higher

Text in Illustration

*1	Rear Airbag Sensor RH
*2	Side Airbag Sensor Assembly RH

NG

REPLACE FLOOR WIRE

OK

12.	CHECK FLOOR WIRE (TO B+)

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

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
S12-1 (BCR+) - Body ground	Ignition switch ON	Below 1 V
S12-2 (BCR-) - Body ground	Ignition switch ON	Below 1 V

Text in Illustration

*1	Rear Airbag Sensor RH
*2	Side Airbag Sensor Assembly RH

NG

REPLACE FLOOR WIRE

OK

13.	CHECK FLOOR WIRE (TO GROUND)

(a) Turn the ignition switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
S12-1 (BCR+) - Body ground	Always	1 MΩ or Higher
S12-2 (BCR-) - Body ground	Always	1 MΩ or Higher

Text in Illustration

*1	Rear Airbag Sensor RH
*2	Side Airbag Sensor Assembly RH

NG

REPLACE FLOOR WIRE

OK

14.

CHECK DTC

(a) Connect the connectors to the airbag sensor assembly.

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

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

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

(e) Turn the ignition switch off.

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

(g) Check for DTCs (See page ).

OK:

DTC B1620/21 is not output.

HINT:

DTCs other than B1620/21 may be output at this time, but they are not related to this check.

Result

Result	Proceed to
NG	A
OK	B

B

REPLACE REAR AIRBAG SENSOR RH

A

15.	CHECK SIDE AIRBAG SENSOR ASSEMBLY RH

(a) Turn the ignition switch off.

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

(c) Replace the airbag sensor assembly (See page ).

HINT:

Perform the inspection using parts from a normal vehicle when possible.

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

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

(f) Clear any DTCs stored in the memory (See page ).

(g) Turn the ignition switch off.

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

(i) Check for DTCs (See page ).

OK:

DTC B1620/21 is not output.

HINT:

DTCs other than B1620/21 may be output at this time, but they are not related to this check.

OK

END

NG

REPLACE SIDE AIRBAG SENSOR ASSEMBLY RH