OCCUPANT CLASSIFICATION SYSTEM, Diagnostic DTC:B1787

DESCRIPTION

DTC B1787 is stored when the occupant detection ECU receives a collision detection signal, which is sent by the rear occupant classification sensor LH when an accident occurs.

DTC B1787 is also stored when the separate type front seat cushion spring assembly*1 and front seat adjuster assembly RH*2 is subjected to a strong impact, even if an actual accident has not occurred.

However, when the occupant detection ECU outputs a collision detection signal, even if the vehicle has not been in a collision, DTC B1787 can be cleared by conducting the zero point calibration and sensitivity check.

Therefore, if DTC B1787 is output, first perform the zero point calibration and sensitivity check.

• *1: for RHD

• *2: for LHD

CAUTION / NOTICE / HINT

PROCEDURE

1. Click here

   CHECK DTC

   
   

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

   2. Clear the DTCs.

      Click here

      
      
      1. Body Electrical > Occupant Detection > Clear DTCs
      2. 
         
      3. 
         
      Tip:
      

      • First clear the DTCs stored in the occupant detection ECU, and then clear the DTCs stored in the airbag sensor assembly.

      • Use the GTS to clear the DTCs of the occupant detection ECU, otherwise the DTCs cannot be cleared.

   3. Turn the ignition switch off.

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

   5. Check for DTCs.

      Click here

      
      
      1. Body Electrical > Occupant Detection > Trouble Codes
      2. 
         
      3. 
         

      Result
      Proceed to DTC B1787 is not output DTC B1787 is output

      Tip:

      DTCs other than DTC B1787 may be output at this time, but they are not related to this check.

   
   
   • DTC B1787 is not output

     USE SIMULATION METHOD TO CHECKClick here

   • DTC B1787 is outputClick here
2. Click here

   PERFORM ZERO POINT CALIBRATION

   
   

   1. Perform the zero point calibration.

      Click here

      Result
      Result Proceed to "Zero Point Calibration is complete." is displayed A "Zero Point Calibration is complete." is not displayed (for RHD) B "Zero Point Calibration is complete." is not displayed (for LHD) C

   
   
   • AClick here
   • BClick here
   • CClick here
3. Click here

   PERFORM SENSITIVITY CHECK

   
   

   1. Perform the sensitivity check.

      Click here

      Standard
      27 to 33 kg (59.5 to 72.8 lb)

      Result
      Proceed to OK NG (for RHD) NG (for LHD)

   
   
   • OKClick here
   • NG (for RHD)Click here

     GO TO STEP 5

   • NG (for LHD)Click here

     GO TO STEP 12

4. Click here

   CHECK DTC

   
   

   1. Clear the DTCs.

      Click here

      
      
      1. Body Electrical > Occupant Detection > Clear DTCs
      2. 
         
      3. 
         
      Tip:
      

      • First clear the DTCs stored in the occupant detection ECU, and then clear the DTCs stored in the airbag sensor assembly.

      • Use the GTS to clear the DTCs of the occupant detection ECU, otherwise the DTCs cannot be cleared.

   2. Turn the ignition switch off.

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

   4. Check for DTCs.

      Click here

      
      
      1. Body Electrical > Occupant Detection > Trouble Codes
      2. 
         
      3. 
         

      Result
      Proceed to DTC B1787 is not output DTC B1787 is output (for RHD) DTC B1787 is output (for LHD)

      Tip:

      DTCs other than DTC B1787 may be output at this time, but they are not related to this check.

   
   
   • DTC B1787 is not output

     END

   • DTC B1787 is output (for RHD)Click here

     GO TO STEP 5

   • DTC B1787 is output (for LHD)Click here

     GO TO STEP 12

5. Click here

   REPLACE SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY (REAR OCCUPANT CLASSIFICATION SENSOR LH)

   
   

   1. Turn the ignition switch off.

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

   3. Replace the separate type front seat cushion spring assembly.

      for Manual Seat:Click here

      for Power Seat:Click here

      Tip:

      Perform the inspection using parts from a normal vehicle when possible.

      Result
      Proceed to NEXT

   
   
   • NEXTClick here
6. Click here

   PERFORM ZERO POINT CALIBRATION

   
   

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

   2. Turn the ignition switch to ON.

   3. Perform the zero point calibration.

      Click here

      Result
      Proceed to "Zero Point Calibration is complete." is displayed "Zero Point Calibration is complete." is not displayed

   
   
   • "Zero Point Calibration is complete." is displayedClick here
   • "Zero Point Calibration is complete." is not displayedClick here
7. Click here

   PERFORM SENSITIVITY CHECK

   
   

   1. Perform the sensitivity check.

      Click here

      Standard
      27 to 33 kg (59.5 to 72.8 lb)

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NGClick here

     GO TO STEP 9

8. Click here

   CHECK DTC

   
   

   1. Clear the DTCs.

      Click here

      
      
      1. Body Electrical > Occupant Detection > Clear DTCs
      2. 
         
      3. 
         
      Tip:
      

      • First clear the DTCs stored in the occupant detection ECU, and then clear the DTCs stored in the airbag sensor assembly.

      • Use the GTS to clear the DTCs of the occupant detection ECU, otherwise the DTCs cannot be cleared.

   2. Turn the ignition switch off.

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

   4. Check for DTCs.

      Click here

      
      
      1. Body Electrical > Occupant Detection > Trouble Codes
      2. 
         
      3. 
         

      Result
      Proceed to DTC B1787 is not output DTC B1787 is output

      Tip:

      DTCs other than DTC B1787 may be output at this time, but they are not related to this check.

   
   
   • DTC B1787 is not output

     END (SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY [REAR OCCUPANT CLASSIFICATION SENSOR LH] WAS DEFECTIVE)

   • DTC B1787 is outputClick here

     GO TO STEP 9

9. Click here

   REPLACE OCCUPANT DETECTION ECU

   
   

   1. Turn the ignition switch off.

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

   3. Replace the occupant detection ECU.

      Click here

      Tip:

      Perform the inspection using parts from a normal vehicle when possible.

      Result
      Proceed to NEXT

   
   
   • NEXTClick here
10. Click here

    PERFORM ZERO POINT CALIBRATION

    
    

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

    2. Turn the ignition switch to ON.

    3. Perform the zero point calibration.

       Click here

       Result
       Proceed to "Zero Point Calibration is complete." is displayed

    
    
    • "Zero Point Calibration is complete." is displayedClick here
11. Click here

    PERFORM SENSITIVITY CHECK

    
    

    1. Perform the sensitivity check.

       Click here

       Standard
       27 to 33 kg (59.5 to 72.8 lb)

       Result
       Proceed to NEXT

    
    
    • NEXT

      END (OCCUPANT DETECTION ECU WAS DEFECTIVE)

12. Click here

    REPLACE FRONT SEAT ADJUSTER ASSEMBLY RH (REAR OCCUPANT CLASSIFICATION SENSOR LH)

    
    

    1. Turn the ignition switch off.

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

    3. Replace the front seat adjuster assembly RH.

       for Manual Seat:Click here

       for Power Seat:Click here

       Tip:

       Perform the inspection using parts from a normal vehicle when possible.

       Result
       Proceed to NEXT

    
    
    • NEXTClick here
13. Click here

    PERFORM ZERO POINT CALIBRATION

    
    

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

    2. Turn the ignition switch to ON.

    3. Perform the zero point calibration.

       Click here

       Result
       Proceed to "Zero Point Calibration is complete." is displayed "Zero Point Calibration is complete." is not displayed

    
    
    • "Zero Point Calibration is complete." is displayedClick here
    • "Zero Point Calibration is complete." is not displayedClick here
14. Click here

    PERFORM SENSITIVITY CHECK

    
    

    1. Perform the sensitivity check.

       Click here

       Standard
       27 to 33 kg (59.5 to 72.8 lb)

       Result
       Proceed to OK NG

    
    
    • OKClick here
    • NGClick here

      GO TO STEP 16

15. Click here

    CHECK DTC

    
    

    1. Clear the DTCs.

       Click here

       
       
       1. Body Electrical > Occupant Detection > Clear DTCs
       2. 
          
       3. 
          
       Tip:
       

       • First clear the DTCs stored in the occupant detection ECU, and then clear the DTCs stored in the airbag sensor assembly.

       • Use the GTS to clear the DTCs of the occupant detection ECU, otherwise the DTCs cannot be cleared.

    2. Turn the ignition switch off.

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

    4. Check for DTCs.

       Click here

       
       
       1. Body Electrical > Occupant Detection > Trouble Codes
       2. 
          
       3. 
          

       Result
       Proceed to DTC B1787 is not output DTC B1787 is output

       Tip:

       DTCs other than DTC B1787 may be output at this time, but they are not related to this check.

    
    
    • DTC B1787 is not output

      END (FRONT SEAT ADJUSTER ASSEMBLY RH [REAR OCCUPANT CLASSIFICATION SENSOR LH] WAS DEFECTIVE)

    • DTC B1787 is outputClick here

      GO TO STEP 16

16. Click here

    REPLACE OCCUPANT DETECTION ECU

    
    

    1. Turn the ignition switch off.

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

    3. Replace the occupant detection ECU.

       Click here

       Tip:

       Perform the inspection using parts from a normal vehicle when possible.

       Result
       Proceed to NEXT

    
    
    • NEXTClick here
17. Click here

    PERFORM ZERO POINT CALIBRATION

    
    

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

    2. Turn the ignition switch to ON.

    3. Perform the zero point calibration.

       Click here

       Result
       Proceed to "Zero Point Calibration is complete." is displayed

    
    
    • "Zero Point Calibration is complete." is displayedClick here
18. Click here

    PERFORM SENSITIVITY CHECK

    
    

    1. Perform the sensitivity check.

       Click here

       Standard
       27 to 33 kg (59.5 to 72.8 lb)

       Result
       Proceed to NEXT

    
    
    • NEXT

      END (OCCUPANT DETECTION ECU WAS DEFECTIVE)