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


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FRONT SEAT OUTER BELT FOR DRIVER SIDE (DRIVER SIDE FRONT PRETENSIONER SQUIB)

CHECK CONNECTOR

CHECK FLOOR WIRE

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

DTC No.
DTC Detection Condition
Trouble Area
B1900/73
When one of following conditions is met:
  1. Center airbag sensor receives line short circuit signal 5 times in driver side front pretensioner squib circuit during primary check
  2. Driver side front pretensioner squib malfunction
  3. Center airbag sensor malfunction
  1. Front seat outer belt for driver side (driver side front pretensioner squib)
  2. Center airbag sensor assembly
  3. Floor wire
B1901/73
When one of following conditions is met:
  1. Center airbag sensor receives open circuit signal in driver side front pretensioner squib circuit for 2 seconds
  2. Driver side front pretensioner squib malfunction
  3. Center airbag sensor malfunction
  1. Front seat outer belt for driver side (driver side front pretensioner squib)
  2. Center airbag sensor assembly
  3. Floor wire
B1902/73
When one of following conditions is met:
  1. Center airbag sensor receives short circuit to ground signal in driver side front pretensioner squib circuit for 0.5 seconds
  2. Driver side front pretensioner squib malfunction
  3. Center airbag sensor malfunction
  1. Front seat outer belt for driver side (driver side front pretensioner squib)
  2. Center airbag sensor assembly
  3. Floor wire
B1903/73
When one of following conditions is met:
  1. Center airbag sensor receives short circuit to B+ signal in driver side front pretensioner squib circuit for 0.5 seconds
  2. Driver side front pretensioner squib malfunction
  3. Center airbag sensor malfunction
  1. Front seat outer belt for driver side (driver side front pretensioner squib)
  2. Center airbag sensor assembly
  3. Floor wire

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Supplemental Restraint System.Airbag System. Dtc B1900/73 Short In Front Driver Side Pretensioner Squib Circuit


INSPECTION PROCEDURE

1.CHECK FRONT SEAT OUTER BELT FOR DRIVER SIDE (DRIVER SIDE FRONT PRETENSIONER SQUIB)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Supplemental Restraint System.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 connector from the driver side front seat outer belt.

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

SST
09843-18060
CAUTION:
Never connect a tester to the driver side front pretensioner squib 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.
  2. Insert SST straight into the terminals of the connector.

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

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

  1. Clear the DTCs (Toyota Fortuner RM000000YVY004X.html).

  1. Turn the ignition switch OFF.

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

  1. Check for DTCs (Toyota Fortuner RM000000YVY004X.html).

    OK:
    DTC B1900, B1901, B1902, B1903 or 73 is not output.
    HINT:
    DTCs other than DTC B1900, B1901, B1902, B1903 or 73 may be output at this time, but they are not related to this check.


OK
REPLACE FRONT SEAT OUTER BELT FOR DRIVER SIDE (DRIVER SIDE FRONT PRETENSIONER SQUIB)
NG


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 (resistance 2.1 Ω) from the floor wire.

  1. Check that the floor wire connector (on the driver side front seat outer belt) is not damaged.

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


NG
REPAIR OR REPLACE FLOOR WIRE
OK


3.CHECK FLOOR WIRE
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Supplemental Restraint System.Airbag System. Dtc B1900/73 Short In Front Driver Side Pretensioner Squib Circuit

  1. Disconnect the connector from the center airbag sensor.

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

  1. Turn the ignition switch ON.

  1. Measure the voltage of the wire harness side connector.

    Standard voltage:
    Tester Connection
    		Specified Condition
    F20-1 (R+) - Body ground
    		Below 1 V
    F20-2 (R-) - Body ground
    		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 of the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Specified Condition
    F20-1 (R+) - F20-2 (R-)
    		Below 1 Ω
    F20-1 (R+) - Body ground
    		1 MΩ or higher
    F20-2 (R-) - Body ground
    		1 MΩ or higher

  1. Release the activation prevention mechanism built into connector B (Toyota Fortuner RM000000YVX004X.html).

  1. Measure the resistance of the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Specified Condition
    F20-1 (R+) - F20-2 (R-)
    		1 MΩ or higher


NG
REPAIR OR REPLACE FLOOR WIRE
OK

REPLACE CENTER AIRBAG SENSOR ASSEMBLY