Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJQS
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1900/73-B1903/73; Short in Front Pretensioner Squib RH Circuit; 2016 - 2020 MY Sienna [12/2015 -        ]

DTC

B1900/73

Short in Front Pretensioner Squib RH Circuit

DTC

B1901/73

Open in Front Pretensioner Squib RH Circuit

DTC

B1902/73

Short to GND in Front Pretensioner Squib RH Circuit

DTC

B1903/73

Short to B+ in Front Pretensioner Squib RH Circuit

DESCRIPTION

The front pretensioner squib RH circuit consists of the center airbag sensor assembly and the front seat outer belt assembly RH.

This circuit signals the SRS to deploy when deployment conditions are met.

These DTCs are recorded when a malfunction is detected in the front pretensioner squib RH circuit.

DTC No.

DTC Detection Condition

Trouble Area

B1900/73

When one of following conditions is met:

  • Center airbag sensor assembly detects line short circuit signal in front pretensioner squib RH circuit 5 times during primary check.
  • Front pretensioner squib RH malfunction
  • Center airbag sensor assembly malfunction
  • No. 2 floor wire
  • Front seat outer belt assembly RH (Front pretensioner squib RH)
  • Center airbag sensor assembly

B1901/73

When one of following conditions is met:

  • Center airbag sensor assembly detects open circuit signal in front pretensioner squib RH circuit for 2 seconds.
  • Front pretensioner squib RH malfunction
  • Center airbag sensor assembly malfunction
  • No. 2 floor wire
  • Front seat outer belt assembly RH (Front pretensioner squib RH)
  • Center airbag sensor assembly

B1902/73

When one of following conditions is met:

  • Center airbag sensor assembly detects short circuit to ground signal in front pretensioner squib RH circuit for 0.5 seconds.
  • Front pretensioner squib RH malfunction
  • Center airbag sensor assembly malfunction
  • No. 2 floor wire
  • Front seat outer belt assembly RH (Front pretensioner squib RH)
  • Center airbag sensor assembly

B1903/73

When one of following conditions is met:

  • Center airbag sensor assembly detects short circuit to B+ signal in front pretensioner squib RH circuit for 0.5 seconds.
  • Front pretensioner squib RH malfunction
  • Center airbag sensor assembly malfunction
  • No. 2 floor wire
  • Front seat outer belt assembly RH (Front pretensioner squib RH)
  • Center airbag sensor assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

  • Perform the simulation method by selecting Check Mode (signal check) with the Techstream (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: CHECK MODE PROCEDURE ).
  • After selecting Check Mode (signal check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city street or rough road (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DIAGNOSIS SYSTEM ).

PROCEDURE

1.

CHECK CONNECTOR

(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 connector is properly connected to the front seat outer belt assembly RH.

OK:

The connector is properly connected.

HINT:

If the connector is not connected securely, reconnect the connector and proceed to the next inspection.

(d) Disconnect the connector from the front seat outer belt assembly RH.

(e) Check that the No. 2 floor wire connector (on the front seat outer belt assembly RH) is not damaged.

OK:

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

NG

REPLACE NO. 2 FLOOR WIRE

OK

2.

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

SST: 09843-18061

(a) Disconnect the connector from the front seat outer belt assembly RH.

(b) Connect SST (resistance 2.1 Ω) to connector C.

CAUTION:

Never connect a tester to the front seat outer belt assembly RH for measurement, as this may lead to a serious injury due to airbag deployment.

NOTICE:

  • Do not forcibly insert SST into the terminals of the connector when connecting.
  • Insert SST straight into the terminals of the connector.

(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 the memory (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DTC CHECK / CLEAR ).

(f) Turn the ignition switch off.

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

(h) Check the DTCs (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DTC CHECK / CLEAR ).

OK:

DTC B1900/73, B1901/73, B1902/73 or B1903/73 is not output.

Text in Illustration

*1

Front Pretensioner Squib RH

*2

Center Airbag Sensor Assembly

*3

Connector C

*a

Front view of wire harness connector

(to Front Pretensioner Squib RH)

HINT:

DTCs other than B1900/73, B1901/73, B1902/73 and B1903/73 may be output at this time, but they are not related to this check.

OK

REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH (FRONT PRETENSIONER SQUIB RH)

NG

3.

CHECK CONNECTOR

(a) Turn the ignition switch off.

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

(c) Disconnect the SST from connector C.

(d) Check that the connector is properly connected to the center airbag sensor assembly.

OK:

The connector is properly connected.

HINT:

If the connector is not connected securely, reconnect the connector and proceed to the next inspection.

(e) Disconnect the connector from the center airbag sensor assembly.

(f) Check that the terminal of the connector is not damaged.

OK:

The terminal is not deformed or damaged.

(g) Check that the short spring for the No. 2 floor wire connector with the activation prevention mechanism is not deformed or damaged.

OK:

The short spring is not deformed or damaged.

NG

REPLACE NO. 2 FLOOR WIRE

OK

4.

CHECK NO. 2 FLOOR WIRE (FRONT PRETENSIONER SQUIB RH - CENTER AIRBAG SENSOR ASSEMBLY)

(a) Connect the cable to the negative battery terminal, 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

L9-1 (R+) - Body ground

Ignition switch ON

Below 1 V

L9-2 (R-) - Body ground

Ignition switch ON

Below 1 V

Text in Illustration

*1

Front Pretensioner Squib RH

*2

Center Airbag Sensor Assembly

*3

No. 2 Floor Wire

*4

Connector C

*a

Front view of wire harness connector

(to Front Pretensioner Squib RH)

(d) Turn the ignition switch off.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

L9-1 (R+) - L9-2 (R-)

Always

Below 1 Ω

(g) Release the activation prevention mechanism built into connector B (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DIAGNOSIS SYSTEM ).

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

L9-1 (R+) - L9-2 (R-)

Always

1 MΩ or higher

L9-1 (R+) - Body ground

Always

1 MΩ or higher

L9-2 (R-) - Body ground

Always

1 MΩ or higher

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

NG

REPLACE NO. 2 FLOOR WIRE

OK

5.

CHECK CENTER AIRBAG SENSOR ASSEMBLY

(a) Connect the connectors to the front seat outer belt assembly RH and the center airbag sensor assembly.

(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 the memory (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DTC CHECK / CLEAR ).

(e) Turn the ignition switch off.

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

(g) Check the DTCs (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DTC CHECK / CLEAR ).

OK:

DTC B1900/73, B1901/73, B1902/73 or B1903/73 is not output.

Text in Illustration

*1

Front Pretensioner Squib RH

*2

Center Airbag Sensor Assembly

HINT:

DTCs other than B1900/73, B1901/73, B1902/73 and B1903/73 may be output at this time, but they are not related to this check.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE CENTER AIRBAG SENSOR ASSEMBLY