Supplemental Restraint Systems. Dtc B1620/21 Side Airbag Sensor Rh Circuit Malfunction

The side airbag sensor RH circuit consists of the center airbag sensor assembly, side airbag sensor RH, door side airbag sensor RH* and rear airbag sensor RH.
The side airbag sensor RH, door side airbag sensor RH* and rear airbag sensor RH detect impacts to the vehicle and send signals to the center airbag sensor assembly to determine if the airbags should be deployed.
DTC B1620/21 is recorded when a malfunction is detected in the side airbag sensor RH circuit.

DTC No.	DTC Detection Condition	Trouble Area
B1620/21	The center airbag sensor assembly receives a 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 RH circuit for 2 seconds. Side airbag sensor RH malfunction Rear airbag sensor RH malfunction Center airbag sensor assembly malfunction	No. 2 floor wire Side airbag sensor RH Rear airbag sensor RH Center airbag sensor assembly

*: w/ Daytime Running Light

WIRING DIAGRAM

Corolla. Zre142 Aze141.Supplemental Restraint Systems.Airbag System.
Dtc
B1620/21 Side Airbag Sensor Rh Circuit Malfunction

INSPECTION PROCEDURE

1.CHECK 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 assembly, side airbag sensor RH and rear airbag sensor RH.
OK:
The connectors are properly connected.
HINT:
If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

Disconnect the connectors from the center airbag sensor assembly, side airbag sensor RH and rear airbag sensor RH.

Check that the terminals of the connectors are not damaged.
OK:
The terminals are not deformed or damaged.

REPLACE NO. 2 FLOOR WIRE

OK

2.CHECK NO. 2 FLOOR WIRE (OPEN)

Using SST, connect terminals 8 (BBR+) and 11 (BBR-) of connector B.

NOTICE:
Do not forcibly insert SST into the terminals of the connector when connecting.

SST: 09843-18040

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
M4-4 (BBR+) - M4-3 (BBR-)
Always
Below 1 Ω

Disconnect SST from connector B.

REPLACE NO. 2 FLOOR WIRE

OK

3.CHECK NO. 2 FLOOR WIRE (SHORT)

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
M4-4 (BBR+) - M4-3 (BBR-)
Always
1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

OK

4.CHECK NO. 2 FLOOR WIRE (SHORT TO B+)

Connect the cable to the negative (-) battery terminal.

Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
M4-4 (BBR+) - Body ground
Ignition switch ON
Below 1 V
M4-3 (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.

REPLACE NO. 2 FLOOR WIRE

OK

5.CHECK NO. 2 FLOOR WIRE (SHORT TO GROUND)

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
M4-4 (BBR+) - Body ground
Always
1 MΩ or higher
M4-3 (BBR-) - Body ground
Always
1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

OK

6.CHECK NO. 2 FLOOR WIRE (OPEN)

w/ Daytime Running Light
1. Using SST, connect terminals 4 (BCR+) and 3 (BCR-) of connector C.
  
  NOTICE:
  Do not forcibly insert SST into the terminals of the connector when connecting.
2. Measure the resistance according to the value(s) in the table below.
  Standard Resistance:
  Tester Connection
  Condition
  Specified Condition
  M4-1 (BCR+) - M4-2 (BCR-)
  Always
  Below 1 Ω

SST: 09843-18040

w/o Daytime Running Light
1. Using SST, connect terminals 2 (BCR+) and 1 (BCR-) of connector C.
  
  NOTICE:
  Do not forcibly insert SST into the terminals of the connector when connecting.
2. Measure the resistance according to the value(s) in the table below.
  Standard Resistance:
  Tester Connection
  Condition
  Specified Condition
  M4-1 (BCR+) - M4-2 (BCR-)
  Always
  Below 1 Ω

SST: 09843-18040

Disconnect SST from connector C.

REPLACE NO. 2 FLOOR WIRE

OK

7.CHECK NO. 2 FLOOR WIRE (SHORT)

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
M4-1 (BCR+) - M4-2 (BCR-)
Always
1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

OK

8.CHECK NO. 2 FLOOR WIRE (SHORT TO B+)

Connect the cable to the negative (-) battery terminal.

Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
M4-1 (BCR+) - Body ground
Ignition switch ON
Below 1 V
M4-2 (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.

REPLACE NO. 2 FLOOR WIRE

OK

9.CHECK NO. 2 FLOOR WIRE (SHORT TO GROUND)

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
M4-1 (BCR+) - Body ground
Always
1 MΩ or higher
M4-2 (BCR-) - Body ground
Always
1 MΩ or higher

REPLACE NO. 2 FLOOR WIRE

OK

10.CHECK SIDE AIRBAG SENSOR RH

Connect the connectors to the center airbag sensor assembly and rear airbag sensor RH.

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

Connect the cable to the negative (-) battery terminal.

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

Clear the DTCs stored in the memory (COROLLA_ZRE142 RM000000XFE0H1X.html).

Turn the ignition switch off.

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

Check for DTCs (COROLLA_ZRE142 RM000000XFE0H1X.html).
Result:
Result
Proceed to
DTC B1620/21 is output.
A
DTC B1625/22 is output.
B
DTCs B1620/21 and B1625/22 are not output.
C
HINT:
Codes other than DTCs B1620/21 and B1625/22 may be output at this time, but they are not related to this check.

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 LH and RH to their original positions and connect the connectors.

REPLACE SIDE AIRBAG SENSOR RH (COROLLA_ZRE142 RM000000UWN09NX.html)

USE SIMULATION METHOD TO CHECK (COROLLA_ZRE142 RM000000XFD0GSX.html)

A

11.CHECK REAR AIRBAG SENSOR RH

Disconnect the connector from the rear airbag sensor RH.

Connect the cable to the negative (-) battery terminal.

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

Clear the DTCs stored in the memory (COROLLA_ZRE142 RM000000XFE0H1X.html).

Turn the ignition switch off.

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

Check for DTCs (COROLLA_ZRE142 RM000000XFE0H1X.html).
OK:
DTC B1620/21 is not output.
HINT:
Codes other than DTC B1620/21 may be output at this time, but they are not related to this check.

REPLACE CENTER AIRBAG SENSOR ASSEMBLY (COROLLA_ZRE142 RM000000UWV074X.html)

REPLACE REAR AIRBAG SENSOR RH (COROLLA_ZRE142 RM000000UWR08QX.html)

Tester Connection	Condition	Specified Condition
M4-4 (BBR+) - M4-3 (BBR-)	Always	Below 1 Ω

Tester Connection	Switch Condition	Specified Condition
M4-4 (BBR+) - Body ground	Ignition switch ON	Below 1 V
M4-3 (BBR-) - Body ground	Ignition switch ON	Below 1 V

Result	Proceed to
DTC B1620/21 is output.	A
DTC B1625/22 is output.	B
DTCs B1620/21 and B1625/22 are not output.	C