DTC B1920/77: Short in Rear Pretensioner Squib RH Circuit; DTC B1921/77: Open in Rear Pretensioner Squib RH Circuit; DTC B1922/77: Short to GND in Rear Pretensioner Squib RH Circuit; DTC B1923/77: Short to B+ in Rear Pretensioner Squib RH Circuit (03/2012 - 07/2012): Procedure

CHECK CONNECTORS

Turn the engine switch off.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the cable from the negative (-) battery terminal.
NOTE:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
Check that the connectors are properly connected to the rear seat outer belt assembly RH and center airbag sensor assembly.
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 rear seat outer belt assembly RH and center airbag sensor assembly.
Check that the terminals of the connectors are not damaged.
OK

The terminals are not deformed or damaged.
Check that the floor wire connector (on the rear seat outer belt assembly RH side) is not damaged.
OK

The lock button is not disengaged, and the claw of the lock is not deformed or damaged.

Check that the short spring for the floor wire with the activation prevention mechanism is not deformed or damaged.

The short spring is not deformed or damaged.

TEXT IN ILLUSTRATION

*1	Rear Pretensioner Squib RH
*2	Center Airbag Sensor Assembly
*3	Floor Wire

NG → REPLACE FLOOR WIRE

OK: Go to next step

CHECK REAR SEAT OUTER BELT ASSEMBLY RH (REAR PRETENSIONER SQUIB RH)

Connect the connector to the center airbag sensor assembly.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Connect SST (resistance 2.1 Ω) to connector C.
WARNING:
Never connect the tester to the rear seat outer belt assembly RH (rear pretensioner squib RH) for measurement, as this may lead to a serious injury due to airbag deployment.
NOTE:
- Do not forcibly insert SST into the terminals of the connector when connecting.
- Insert SST straight into the terminals of the connector.
- SST: 09843-18061
Connect the cable to the negative (-) battery terminal.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Clear the DTCs stored in the memory. Refer to DTC CHECK / CLEAR [03/2012 - ] .
Turn the engine switch off.
Turn the engine switch on (IG), and wait for at least 60 seconds.

Check for DTCs. Refer to DTC CHECK / CLEAR [03/2012 - ] .

DTC B1920, B1921, B1922, B1923, or 77 is not output.

TEXT IN ILLUSTRATION

*1	Rear Pretensioner Squib RH
*2	Center Airbag Sensor Assembly
*3	Front view of wire harness connector (to Rear Seat Outer Belt Assembly RH)
*4	Connector C

HINT:

Codes other than DTC B1920, B1921, B1922, B1923, and 77 may be output at this time, but they are not related to this check.

NG → See step 3

OK → See step 7

CHECK FLOOR WIRE (REAR PRETENSIONER SQUIB RH CIRCUIT)

Turn the engine switch off.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the cable from the negative (-) battery terminal.
NOTE:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
Disconnect SST from connector C.
Disconnect the floor wire from the center airbag sensor assembly.

Check for a short to B+ in the circuit.

Connect the cable to the negative (-) battery terminal.
Turn the engine switch on (IG).

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

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
O21-1 (RR+) - Body ground	Engine switch on (IG)	Below 1 V
O21-2 (RR-) - Body ground	Engine switch on (IG)	Below 1 V

Check for an open in the circuit.

Turn the engine switch off.
Disconnect the cable from the negative (-) battery terminal.
NOTE:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
O21-1 (RR+) - O21-2 (RR-)	Always	Below 1 Ω

Check for a short to ground in the circuit.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
O21-1 (RR+) - Body ground	Always	1 MΩ or higher
O21-2 (RR-) - Body ground	Always	1 MΩ or higher

Check for a short in the circuit.

Release the activation prevention mechanism built into connector B. Refer to DIAGNOSIS SYSTEM [03/2012 - ] .

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

Standard Resistance

Tester Connection	Condition	Specified Condition
O21-1 (RR+) - O21-2 (RR-)	Always	1 MΩ or higher

TEXT IN ILLUSTRATION

*1	Rear Pretensioner Squib RH
*2	Center Airbag Sensor Assembly
*3	Floor Wire
*4	Front view of wire harness connector (to Rear Seat Outer Belt Assembly RH)
*5	Connector C

NG → REPLACE FLOOR WIRE

OK: Go to next step

CHECK CENTER AIRBAG SENSOR ASSEMBLY

Restore the released activation prevention mechanism of connector B to the original condition.

Connect the connectors to the rear seat outer belt assembly RH and center airbag sensor assembly.
Connect the cable to the negative (-) battery terminal.
Turn the engine switch on (IG), and wait for at least 60 seconds.
Clear the DTCs stored in the memory. Refer to DTC CHECK / CLEAR [03/2012 - ] .
Turn the engine switch off.
Turn the engine switch on (IG), and wait for at least 60 seconds.

Check for DTCs. Refer to DTC CHECK / CLEAR [03/2012 - ] .

DTC B1920, B1921, B1922, B1923, or 77 is not output.

TEXT IN ILLUSTRATION

*1	Rear Pretensioner Squib RH
*2	Center Airbag Sensor Assembly

HINT:

Codes other than DTC B1920, B1921, B1922, B1923, and 77 may be output at this time, but they are not related to this check.

NG → See step 6

OK → See step 5

USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [03/2012 - 07/2012]
REPLACE CENTER AIRBAG SENSOR ASSEMBLY. Refer to REMOVAL [03/2012 - 07/2012]
REPLACE REAR SEAT OUTER BELT ASSEMBLY RH. Refer to REMOVAL [03/2012 - 07/2012]