Dtc B1900/73 Short In Front Driver Side Pretensioner Squib Circuit

Vehicle Interior. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
Supplemental Restraint Systems. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FRONT SEAT OUTER BELT ASSEMBLY LH

CHECK CONNECTOR

CHECK NO. 2 FLOOR WIRE (FRONT SEAT OUTER BELT ASSEMBLY LH)

CHECK CENTER AIRBAG SENSOR

DTC B1900/73 Short in Front Driver Side Pretensioner Squib Circuit

DTC B1901/73 Open in Front Driver Side Pretensioner Squib Circuit

DTC B1902/73 Short to GND in Front Driver Side Pretensioner Squib Circuit

DTC B1903/73 Short to B+ in Front Driver Side Pretensioner Squib Circuit


DESCRIPTION

The front pretensioner squib circuit consists of the center airbag sensor and front seat outer belt assembly LH.
This circuit instructs the SRS to deploy when deployment conditions are met.
These DTCs are stored when a malfunction is detected in the front seat outer belt assembly LH circuit.

DTC Code
DTC Detection Condition
Trouble Area
B1900/73
One of the following conditions is met:
  1. The center airbag sensor detects a line short circuit signal 5 times in the front seat outer belt assembly LH circuit during the primary check.
  2. A front seat outer belt assembly LH malfunction.
  3. A center airbag sensor malfunction.
  1. No. 2 floor wire
  2. Front seat outer belt assembly LH
  3. Center airbag sensor assembly
B1901/73
One of the following conditions is met:
  1. The center airbag sensor detects an open circuit signal in the front seat outer belt assembly LH circuit for 2 seconds.
  2. A front seat outer belt assembly LH malfunction.
  3. A center airbag sensor malfunction.
B1902/73
One of the following conditions is met:
  1. The center airbag sensor detects a short circuit to ground signal in the front seat outer belt assembly LH circuit for 0.5 seconds.
  2. A front seat outer belt assembly LH malfunction.
  3. A center airbag sensor malfunction.
B1903/73
One of the following conditions is met:
  1. The center airbag sensor detects a short circuit to B+ signal in the front seat outer belt assembly LH circuit for 0.5 seconds.
  2. A front seat outer belt assembly LH malfunction.
  3. A center airbag sensor malfunction.

WIRING DIAGRAM


Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Supplemental Restraint Systems.Airbag System.
Dtc
  B1900/73  Short In Front Driver Side Pretensioner Squib Circuit


INSPECTION PROCEDURE

NOTICE:
  1. After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (HILUX_TGN26 RM000004QR1006X.html).
  2. When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected (HILUX_TGN26 RM000004QR3009X.html).
HINT:
To perform the simulation method, enter check mode (signal check) with the intelligent tester (HILUX_TGN26 RM000000XFF0AKX.html), and then wiggle each connector of the airbag system or drive the vehicle on various types of road (HILUX_TGN26 RM000000XFD0G9X.html).
1.CHECK FRONT SEAT OUTER BELT ASSEMBLY LH


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Supplemental Restraint Systems.Airbag System.
Dtc
  B1900/73  Short In Front Driver Side Pretensioner Squib Circuit
  1. Turn the ignition switch off.

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

  1. Disconnect the connectors from the front seat outer belt assembly LH.

  1. Connect the white wire side of SST (resistance: 2.1 Ω) to connector C.

    CAUTION:
    Never connect the tester to the front seat outer belt assemblyLH for measurement, as this may lead to a serious injury due to airbag deployment.
    NOTICE:
    1. Do not forcibly insert SST into the terminals of the connector when connecting SST.
    2. Insert SST straight into the terminals of the connector.
SST
09843-18061
  1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

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

  1. Clear the DTCs (HILUX_TGN26 RM000000XFE0GHX.html).

  1. Turn the ignition switch off.

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

  1. Check for DTCs (HILUX_TGN26 RM000000XFE0GHX.html).

    OK:
    DTC B1900/73, B1901/73, B1902/73 or B1903/73 is not output.
    HINT:
    Codes other than DTC B1900/73, B1901/73, B1902/73 and B1903/73 may be output at this time, but they are not related to this check.
    Text in Illustration
    *1
    Front Seat Outer Belt Assembly LH
    *2
    Center Airbag Sensor
    *3
    Connector C
    *4
    SST
    *a
    Front view of wire harness connector
    (to Front Seat Outer Belt Assembly LH)


NG
Go to step 2
OK

REPLACE FRONT SEAT OUTER BELT ASSEMBLY LH (HILUX_TGN26 RM00000120B06PX.html)

2.CHECK CONNECTOR
  1. Turn the ignition switch off.

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

  1. Disconnect SST from connector C.

  1. Disconnect the connectors from the center airbag sensor.



    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Supplemental Restraint Systems.Airbag System.
Dtc
  B1900/73  Short In Front Driver Side Pretensioner Squib Circuit
  1. Check that the connectors (on the center airbag sensor side and front seat outer belt assembly LH side) are not damaged.

    OK:
    The lock button is not disengaged, and the claw of the lock is not deformed or damaged.
    Text in Illustration
    *1
    Front Seat Outer Belt Assembly LH
    *2
    No. 2 Floor Wire
    *3
    Center Airbag Sensor


NG
REPLACE NO. 2 FLOOR WIRE
OK


3.CHECK NO. 2 FLOOR WIRE (FRONT SEAT OUTER BELT ASSEMBLY LH)


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Supplemental Restraint Systems.Airbag System.
Dtc
  B1900/73  Short In Front Driver Side Pretensioner Squib Circuit
  1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    Switch Condition
    Specified Condition
    K41-1 (L+) - Body ground
    Ignition switch ON
    Below 1 V
    K41-2 (L-) - Body ground
    Ignition switch ON
    Below 1 V
  1. Turn the ignition switch off.

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

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

    Standard Resistance:
    Tester Connection
    Condition
    Specified Condition
    K41-1 (L+) - K41-2 (L-)
    Always
    Below 1 Ω
  1. Release the activation prevention mechanism built into connector B (HILUX_TGN26 RM000000XFD0G9X.html).

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

    Standard Resistance:
    Tester Connection
    Condition
    Specified Condition
    K41-1 (L+) - K41-2 (L-)
    Always
    1 MΩ or higher
    K41-1 (L+) - Body ground
    Always
    1 MΩ or higher
    K41-2 (L-) - Body ground
    Always
    1 MΩ or higher
  1. Restore the released activation prevention mechanism of connector B to its original condition.

Text in Illustration
*1
Front Seat Outer Belt Assembly LH
*2
No. 2 Floor Wire
*3
Center Airbag Sensor
*4
Connector C
*a
Front view of wire harness connector
(to Front Seat Outer Belt Assembly LH)


NG
REPLACE NO. 2 FLOOR WIRE
OK


4.CHECK CENTER AIRBAG SENSOR


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.Supplemental Restraint Systems.Airbag System.
Dtc
  B1900/73  Short In Front Driver Side Pretensioner Squib Circuit
  1. Connect the connectors to the front seat outer belt assembly LH and center airbag sensor.

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

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

  1. Clear the DTCs (HILUX_TGN26 RM000000XFE0GHX.html).

  1. Turn the ignition switch off.

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

  1. Check for DTCs (HILUX_TGN26 RM000000XFE0GHX.html).

    OK:
    DTC B1900/73, B1901/73, B1902/73 or B1903/73 is not output.
    HINT:
    Codes other than DTC B1900/73, B1901/73, B1902/73 and B1903/73 may be output at this time, but they are not related to this check.
    Text in Illustration
    *1
    Front Seat Outer Belt Assembly LH
    *2
    Center Airbag Sensor


NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY (HILUX_TGN26 RM0000010IE013X.html)
OK

USE SIMULATION METHOD TO CHECK (HILUX_TGN26 RM000000XFD0G9X.html)