DTC    B1782    Rear Occupant Classification Sensor LH Circuit Malfunction

for Preparation Click here

DESCRIPTION

HINT:

1. When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1782 of the occupant classification system.
   
2. Use the Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.
   

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

1. After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work (Click here).
   
2. When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected (Click here).
   

HINT:

1. If troubleshooting (wire harness inspection) is difficult to perform, remove the front seat RH installation bolts to see the undersurface of the seat cushion.
   
2. In the above case, hold the seat so that it does not fall down. Holding the seat for a long period of time may cause problems, such as seat rail deformation. Hold the seat up only for as long as necessary.
   

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

2. Clear any DTCs stored in the memory (Click here).
   

   HINT:

   1. First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
      
   2. Use the Techstream to clear the DTCs of the occupant classification 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. Using the Techstream, check for DTCs of the occupant classification ECU (Click here).
   

   OK:

   DTC B1782 is not output.
   

   HINT:

   DTCs other than DTC B1782 may be output at this time, but they are not related to this check.

NG	Go to step 2

OK
USE SIMULATION METHOD TO CHECK (Click here)

1. Turn the ignition switch off.
   

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

3. Check that the connectors are properly connected to the occupant classification ECU and the rear occupant detection sensor LH.
   

   OK:

   Connectors are properly connected.
   

NG	CONNECT CONNECTOR

OK

1. Check that the connectors (on the occupant classification ECU side and rear occupant detection sensor LH side) are not damaged (Click here).
   

   OK:

   Connectors are not deformed or damaged.
   

NG	REPLACE FRONT SEAT WIRE RH

OK

1. Disconnect the connectors from the occupant classification ECU and the rear occupant detection sensor LH.
   

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

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

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

   Standard voltage:

   Tester Connection	Switch Condition	Specified Condition
   Y1-3 (SGD3) - Body ground	Ignition switch ON	Below 1 V
   Y1-5 (SVC3) - Body ground
   Y1-9 (SIG3) - Body ground

5. Turn the ignition switch off.
   

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

7. Using service wires, connect terminals 1 (SVC3) and 3 (SGD3), and connect terminals 2 (SIG3) and 3 (SGD3) of connector C.
   

   NOTICE:

   Do not forcibly insert the service wires into the terminals of the connector.

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

   Standard resistance:

   Tester Connection	Condition	Specified Condition
   Y1-5 (SVC3) - Y1-3 (SGD3)	Always	Below 1 Ω
   Y1-9 (SIG3) - Y1-3 (SGD3)

9. Disconnect the service wires from connector C.
   

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

    Standard resistance:

    Tester Connection	Condition	Specified Condition
    Y1-5 (SVC3) - Y1-3 (SGD3)	Always	1 MΩ or higher
    Y1-9 (SIG3) - Y1-3 (SGD3)
    Y1-5 (SVC3) - Y1-9 (SIG3)
    Y1-3 (SGD3) - Body ground
    Y1-5 (SVC3) - Body ground
    Y1-9 (SIG3) - Body ground

NG	REPLACE FRONT SEAT WIRE RH

OK

1. Connect the connectors to the occupant classification ECU and the rear occupant detection sensor LH.
   

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

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

4. Clear any DTCs stored in the memory (Click here).
   

   HINT:

   1. First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
      
   2. Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
      

5. Turn the ignition switch off.
   

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

7. Using the Techstream, check for DTCs of the occupant classification ECU (Click here).
   

   OK:

   DTC B1782 is not output.
   

   HINT:

   DTCs other than DTC B1782 may be output at this time, but they are not related to this check.

NG	Go to step 6

OK
USE SIMULATION METHOD TO CHECK (Click here)

1. Turn the ignition switch off.
   

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

3. Replace the occupant classification ECU.
   

   1. for Manual Seat (Click here)
      
   2. for Power Seat (Click here)
      

   HINT:

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

NEXT

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

2. Connect the Techstream to the DLC3.
   

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

4. Using the Techstream, perform the zero point calibration (Click here).
   

NG	Go to step 10

OK

1. Using the Techstream, perform the sensitivity check (Click here).
   

   Standard range:

   27 to 33 kg (59.5 to 72.8 lb)
   

NG	Go to step 10

OK

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

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

   HINT:

   1. First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
      
   2. Use the Techstream to clear the DTCs of the occupant classification 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. Using the Techstream, check for DTCs of the occupant classification ECU (Click here).
   

   OK:

   DTC B1782 is not output.
   

   HINT:

   DTCs other than DTC B1782 may be output at this time, but they are not related to this check.

NG	Go to step 10

OK
END

1. Turn the ignition switch off.
   

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

3. Replace the front seat frame with adjuster RH (Click here).
   

   HINT:

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

NEXT

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

2. Connect the Techstream to the DLC3.
   

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

4. Using the Techstream, perform the zero point calibration (Click here).
   

NEXT

1. Using the Techstream, perform the sensitivity check (Click here).
   

   Standard range:

   27 to 33 kg (59.5 to 72.8 lb)
   

NEXT
END