AIRBAG SYSTEM, Diagnostic DTC:B1900/73, B1901/73, B1902/73, B1903/73

DESCRIPTION

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

This 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.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK FRONT SEAT OUTER BELT ASSEMBLY (DRIVER SIDE FRONT PRETENSIONER SQUIB)

   
   

   1. 

      Turn the ignition switch to the LOCK position.

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

   3. LHD

      
      

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

   4. RHD

      
      

      1. Disconnect the connector from the front seat outer belt assembly RH.

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

      CAUTION:

      Never connect a tester to the front seat outer belt assembly (Driver side front pretensioner squib) for measurement, as this may lead to a serious injury due to airbag deployment.

      Note

      
      

      • Do not forcibly insert the SST into the terminals of the connector.

      • Insert the SST straight into the terminals of the connector.

      SST

      09843-18060

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

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

   8. Clear the DTCs stored in memory Click here.

   9. Turn the ignition switch to the LOCK position.

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

   11. Check the DTCs Click here.

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

       Tech Tips

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

   
   

   OK

   REPLACE FRONT SEAT OUTER BELT ASSEMBLY LH (LHD)

   OK

   REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH (RHD)

   NG

2. CHECK CONNECTOR

   
   

   1. Turn the ignition switch to the LOCK position.

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

   3. Disconnect the SST from connector "C".

   4. Check that the engine room main wire connector (on the front seat outer belt assembly side) 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 ENGINE ROOM MAIN WIRE

   OK

3. CHECK ENGINE ROOM MAIN WIRE (DRIVER SIDE FRONT PRETENSIONER SQUIB CIRCUIT)

   
   

   1. 

      Disconnect the connectors from the center airbag sensor assembly.

   2. Check for short to B+ in the circuit.

      
      

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

      2. Turn the ignition switch to the ON position.

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

         Voltage
         Tester connection Condition Specified condition B23-1 (L+) - Body ground (LHD) Ignition switch ON Below 1 V B23-2 (L-) - Body ground (LHD) Ignition switch ON Below 1 V B25-1 (R+) - Body ground (RHD) Ignition switch ON Below 1 V B25-2 (R-) - Body ground (RHD) Ignition switch ON Below 1 V

   3. Check for open in the circuit.

      
      

      1. Turn the ignition switch to the LOCK position.

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

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

         Resistance
         Tester connection Condition Specified condition B23-1 (L+) - B23-2 (L-) (LHD) Always Below 1 Ω B25-1 (R+) - B25-2 (R-) (RHD) Always Below 1 Ω

   4. Check for short to ground in the circuit.

      
      

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

         Resistance
         Tester connection Condition Specified condition B23-1 (L+) - Body ground (LHD) Always 1 MΩ or higher B23-2 (L-) - Body ground (LHD) Always 1 MΩ or higher B25-1 (R+) - Body ground (RHD) Always 1 MΩ or higher B25-2 (R-) - Body ground (RHD) Always 1 MΩ or higher

   5. Check for short in the circuit.

      
      

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

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

         Resistance
         Tester connection Condition Specified condition B23-1 (L+) - B23-2 (L-) (LHD) Always 1 MΩ or higher B25-1 (R+) - B25-2 (R-) (RHD) Always 1 MΩ or higher

   
   

   NG

   REPAIR OR REPLACE ENGINE ROOM MAIN WIRE

   OK

4. CHECK CENTER AIRBAG SENSOR ASSEMBLY

   
   

   1. 

      Connect the connectors to the front seat outer belt assembly and the center airbag sensor assembly.

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

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

   4. Clear the DTCs stored in memory Click here.

   5. Turn the ignition switch to the LOCK position.

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

   7. Check the DTCs Click here.

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

      Tech Tips

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

   
   

   NG

   REPLACE CENTER AIRBAG SENSOR ASSEMBLY

   OK

   USE SIMULATION METHOD TO CHECK