Dtc B1782 Rear Occupant Classification Sensor Lh Circuit Malfunction

Vehicle Interior. Yaris. Ncp93, 131
Supplemental Restraint Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FOR DTC

CHECK CONNECTION OF CONNECTOR

CHECK CONNECTOR

CHECK FRONT SEAT WIRE RH

CHECK FOR DTC

REPLACE SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY

PERFORM ZERO POINT CALIBRATION AND SENSITIVITY CHECK

DTC B1782 Rear Occupant Classification Sensor LH Circuit Malfunction


DESCRIPTION

The rear occupant classification sensor LH circuit consists of the occupant classification ECU and the rear occupant classification sensor LH.
DTC B1782 is stored when a malfunction is detected in the rear occupant classification sensor LH circuit.

DTC Code
DTC Detection Condition
Trouble Area
B1782
One of following conditions is met:
  1. Occupant classification ECU receives line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in rear occupant classification sensor LH circuit for 2 seconds
  2. Rear occupant classification sensor LH malfunction
  1. Separate type front seat cushion spring assembly (Rear occupant classification sensor LH)
  2. Front seat wire RH
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


Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan). Dtc B1782 Rear Occupant Classification Sensor Lh Circuit Malfunction


INSPECTION PROCEDURE

HINT:
  1. If troubleshooting (wire harness inspection) is difficult to perform, remove the front seat assembly 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.CHECK FOR DTC

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

  1. Clear any DTCs stored in the memory (YARIS_NCP93 RM0000010VK072X.html).

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

  1. Turn the ignition switch off.

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

  1. Using the Techstream, check for DTCs of the occupant classification ECU (YARIS_NCP93 RM0000010VK072X.html).

    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 (YARIS_NCP93 RM0000010VJ076X.html)

2.CHECK CONNECTION OF 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 connectors are properly connected to the occupant classification ECU and the rear occupant classification sensor LH.

    OK:
    Connectors are properly connected.


NG
CONNECT CONNECTORS PROPERLY
OK


3.CHECK CONNECTOR

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

    OK:
    Connectors are not deformed or damaged.


NG
REPLACE FRONT SEAT WIRE RH (YARIS_NCP93 RM000001WB001FX.html)
OK


4.CHECK FRONT SEAT WIRE RH

Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan). Dtc B1782 Rear Occupant Classification Sensor Lh Circuit Malfunction


Text in Illustration
*1
Rear Occupant Classification Sensor LH
*2
Occupant Classification ECU
*3
Front Seat Wire RH
*4
Service Wire
*a
Front view of wire harness connector
(to Occupant Classification ECU)
*b
Front view of wire harness connector
(to Rear Occupant Classification Sensor LH)
*c
Connector B
*d
Connector C

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

  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
    X3-1 - Body ground
    		Ignition switch ON
    		Below 1 V
    X3-3 - Body ground
    X3-5 - Body ground

  1. Turn the ignition switch off.

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

  1. 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.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    X3-1 - X3-5
    		Always
    		Below 1 Ω
    X3-3 - X3-5

  1. Disconnect the service wires from connector C.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    X3-1 - X3-5
    		Always
    		1 MΩ or higher
    X3-1 - X3-3
    X3-3 - X3-5
    X3-1 - Body ground
    X3-3 - Body ground
    X3-5 - Body ground


NG
REPLACE FRONT SEAT WIRE RH (YARIS_NCP93 RM000001WB001FX.html)
OK


5.CHECK FOR DTC

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

  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 any DTCs stored in the memory (YARIS_NCP93 RM0000010VK072X.html).

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

  1. Turn the ignition switch off.

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

  1. Using the Techstream, check for DTCs of the occupant classification ECU (YARIS_NCP93 RM0000010VK072X.html).

    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 (YARIS_NCP93 RM0000010VJ076X.html)

6.REPLACE SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY

  1. Turn the ignition switch off.

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

  1. Replace the separate type front seat cushion spring assembly (YARIS_NCP93 RM000001WB001FX.html).

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

NEXT


7.PERFORM ZERO POINT CALIBRATION AND SENSITIVITY CHECK

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

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Using the Techstream, perform Zero Point Calibration and Sensitivity Check (YARIS_NCP93 RM0000010VN073X.html).


NEXT

END