DTC    B1875/67    Short in Passenger Side Front Seat Cushion Squib Circuit

DTC    B1876/67    Open in Passenger Side Front Seat Cushion Squib Circuit

DTC    B1877/67    Short to GND in Passenger Side Front Seat Cushion Squib Circuit

DTC    B1878/67    Short to B+ in Passenger Side Front Seat Cushion Squib Circuit

for Preparation Click here


DESCRIPTION

The seat cushion squib circuit consists of the center airbag sensor assembly and the SRS seat cushion airbag assembly.
This circuit instructs the SRS to deploy when deployment conditions are met.
These DTCs are recorded when a malfunction is detected in the seat cushion squib circuit.

DTC No.
DTC Detection Condition
Trouble Area
B1875/67
When one of following conditions is met:
  1. The center airbag sensor assembly receives a line short circuit signal 5 times in the seat cushion squib circuit during primary check.
  2. Seat cushion squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. SRS seat cushion airbag assembly (Seat cushion squib)
  3. Center airbag sensor assembly
B1876/67
When one of following conditions is met:
  1. The center airbag sensor assembly receives an open circuit signal in the seat cushion squib circuit for 2 seconds.
  2. Seat cushion squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. SRS seat cushion airbag assembly (Seat cushion squib)
  3. Center airbag sensor assembly
B1877/67
When one of following conditions is met:
  1. The center airbag sensor assembly receives a short circuit to ground signal in the seat cushion squib circuit for 0.5 seconds.
  2. Seat cushion squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. SRS seat cushion airbag assembly (Seat cushion squib)
  3. Center airbag sensor assembly
B1878/67
When one of following conditions is met:
  1. The center airbag sensor assembly receives a short circuit to B+ signal in the seat cushion squib circuit for 0.5 seconds.
  2. Seat cushion squib malfunction
  3. Center airbag sensor assembly malfunction
  1. Floor wire
  2. SRS seat cushion airbag assembly (Seat cushion squib)
  3. Center airbag sensor assembly

WIRING DIAGRAM


C157591E99


INSPECTION PROCEDURE

HINT:
  1. Perform the simulation method by selecting Check Mode (signal check) with the intelligent tester (Click here).
  2. 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 (Click here).

1.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. Check that the connector is properly connected to the SRS seat cushion airbag assembly.

    OK:
    The connector is properly connected.

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

  1. Disconnect the connector from the SRS seat cushion airbag assembly.

  1. 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 SRS SEAT CUSHION AIRBAG ASSEMBLY (SEAT CUSHION SQUIB)
C196978E01
SST
09843-18061  

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

    CAUTION:
    Never connect the tester to the SRS seat cushion airbag assembly (seat cushion 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 SST.
    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 to ON, and wait for at least 60 seconds.

  1. Clear the DTCs stored in the memory (Click here).

  1. Turn the ignition switch off.

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

  1. Check for DTCs (Click here).

    OK:
    DTC B1875, B1876, B1877, B1878 or 67 is not output.

    Text in Illustration 
    *1
    		Seat Cushion Squib
    *2
    		Center Airbag Sensor Assembly
    *3
    		Front view of wire harness connector
    (to Seat Cushion Squib)
    *4
    		Connector C
    *5
    		Color: Black

    HINT:
    DTCs other than B1875, B1876, B1877, B1878 and 67 may be output at this time, but they are not related to this check.



NG
Go to step 3
OK

REPLACE FRONT SEAT ASSEMBLY (PASSENGER SIDE) (Click here)  

3.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. Check that the connector is properly connected to the center airbag sensor assembly.

    OK:
    The connector is properly connected.

  1. Disconnect the connector from the center airbag sensor assembly.

  1. Check that the terminal of the connector is not damaged.

    OK:
    The terminal is not deformed or damaged.

  1. 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 (SEAT CUSHION SQUIB - CENTER AIRBAG SENSOR ASSEMBLY)
C196979E01

  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
    G20-1 (FCP-) - Body ground
    		Ignition switch ON
    		Below 1 V
    G20-2 (FCP+) - Body ground
    		Ignition switch ON
    		Below 1 V

    Text in Illustration 
    *1
    		Seat Cushion Squib
    *2
    		Floor Wire
    *3
    		Center Airbag Sensor Assembly
    *4
    		Front view of wire harness connector
    (to Seat Cushion Squib)
    *5
    		Connector C

  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
    G20-1 (FCP-) - G20-2 (FCP+)
    		Always
    		Below 1 Ω

  1. Release the activation prevention mechanism built into connector B (Click here).

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    G20-1 (FCP-) - G20-2 (FCP+)
    		Always
    		1 MΩ or higher
    G20-1 (FCP-) - Body ground
    		Always
    		1 MΩ or higher
    G20-2 (FCP+) - Body ground
    		Always
    		1 MΩ or higher



NG
REPLACE FLOOR WIRE
OK


5.CHECK CENTER AIRBAG SENSOR ASSEMBLY
C146261E35

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

  1. Connect the connectors to the SRS seat cushion airbag assembly and the center airbag sensor assembly.

  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 stored in the memory (Click here).

  1. Turn the ignition switch off.

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

  1. Check for DTCs (Click here).

    OK:
    DTC B1875, B1876, B1877, B1878 or 67 is not output.

    Text in Illustration 
    *1
    		Seat Cushion Squib
    *2
    		Center Airbag Sensor Assembly

    HINT:
    DTCs other than B1875, B1876, B1877, B1878 and 67 may be output at this time, but they are not related to this check.



NG
REPLACE CENTER AIRBAG SENSOR ASSEMBLY (Click here)
OK

USE SIMULATION METHOD TO CHECK (Click here)