Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJQR
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1825/56-B1828/56; Short in Side Squib LH Circuit; 2016 - 2020 MY Sienna [12/2015 -        ]

DTC

B1825/56

Short in Side Squib LH Circuit

DTC

B1826/56

Open in Side Squib LH Circuit

DTC

B1827/56

Short to GND in Side Squib LH Circuit

DTC

B1828/56

Short to B+ in Side Squib LH Circuit

DESCRIPTION

The side squib LH circuit consists of the center airbag sensor assembly and the front seat side airbag assembly LH.

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

These DTCs are recorded when a malfunction is detected in the side squib LH circuit.

DTC No.

DTC Detection Condition

Trouble Area

B1825/56

When one of following conditions is met:

  • The center airbag sensor assembly receives a line short circuit signal 5 times in the side squib LH circuit during primary check.
  • Side squib LH malfunction
  • Center airbag sensor assembly malfunction
  • Floor wire
  • Front seat side airbag assembly LH (Side squib LH)
  • Center airbag sensor assembly

B1826/56

When one of following conditions is met:

  • The center airbag sensor assembly receives an open circuit signal in the side squib LH circuit for 2 seconds.
  • Side squib LH malfunction
  • Center airbag sensor assembly malfunction
  • Floor wire
  • Front seat side airbag assembly LH (Side squib LH)
  • Center airbag sensor assembly

B1827/56

When one of following conditions is met:

  • The center airbag sensor assembly receives a short circuit to ground signal in the side squib LH circuit for 0.5 seconds.
  • Side squib LH malfunction
  • Center airbag sensor assembly malfunction
  • Floor wire
  • Front seat side airbag assembly LH (Side squib LH)
  • Center airbag sensor assembly

B1828/56

When one of following conditions is met:

  • The center airbag sensor assembly receives a short circuit to B+ signal in the side squib LH circuit for 0.5 seconds.
  • Side squib LH malfunction
  • Center airbag sensor assembly malfunction
  • Floor wire
  • Front seat side airbag assembly LH (Side squib LH)
  • 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 various types of roads (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 side airbag assembly LH.

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 side airbag assembly LH.

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

OK:

The terminal is not deformed or damaged.

NG

REPLACE FLOOR WIRE

OK

2.

CHECK FRONT SEAT SIDE AIRBAG ASSEMBLY LH (SIDE SQUIB LH)

SST: 09843-18061

(a) Connect SST (resistance: 2.1 Ω) to connector C.

CAUTION:

Never connect the tester to the front seat side airbag assembly LH (side squib LH) 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 SST.
  • Insert SST straight into the terminals of the connector.

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

OK:

DTC B1825/56, B1826/56, B1827/56 or B1828/56 is not output.

Text in Illustration

*1

Side Squib LH

*2

Center Airbag Sensor Assembly

*3

Connector C

*a

Front view of wire harness connector

(to Side Squib LH)

HINT:

DTCs other than B1825/56, B1826/56, B1827/56 and B1828/56 may be output at this time, but they are not related to this check.

OK

REPLACE FRONT SEAT SIDE AIRBAG ASSEMBLY LH (SIDE SQUIB LH)

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 SST from connector C.

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

OK:

The connector is properly connected.

(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 floor wire connector with the activation prevention mechanism is not deformed or damaged.

OK:

The short spring is not deformed or damaged.

NG

REPLACE FLOOR WIRE

OK

4.

CHECK FLOOR WIRE (SIDE SQUIB LH - 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

K23-1 (SFL+) - Body ground

Ignition switch ON

Below 1 V

K23-2 (SFL-) - Body ground

Ignition switch ON

Below 1 V

Text in Illustration

*1

Side Squib LH

*2

Center Airbag Sensor Assembly

*3

Floor Wire

*4

Connector C

*a

Front view of wire harness connector

(to Side Squib LH)

(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

K23-1 (SFL+) - K23-2 (SFL-)

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

K23-1 (SFL+) - K23-2 (SFL-)

Always

1 MΩ or higher

K23-1 (SFL+) - Body ground

Always

1 MΩ or higher

K23-2 (SFL-) - Body ground

Always

1 MΩ or higher

NG

REPLACE FLOOR WIRE

OK

5.

CHECK CENTER AIRBAG SENSOR ASSEMBLY

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

(b) Connect the connectors to the front seat side airbag assembly LH and the center airbag sensor assembly.

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

OK:

DTC B1825/56, B1826/56, B1827/56 or B1828/56 is not output.

Text in Illustration

*1

Side Squib LH

*2

Center Airbag Sensor Assembly

HINT:

DTCs other than B1825/56, B1826/56, B1827/56 and B1828/56 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