Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJRV
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1783; Rear Occupant Classification Sensor RH Circuit Malfunction; 2016 - 2020 MY Sienna [12/2015 -        ]

DTC

B1783

Rear Occupant Classification Sensor RH Circuit Malfunction

DESCRIPTION

The rear occupant classification sensor RH circuit consists of the occupant classification ECU and the rear occupant classification sensor RH.

DTC B1783 is stored when a malfunction is detected in the rear occupant classification sensor RH circuit.

DTC Code

DTC Detection Condition

Trouble Area

B1783

One of following conditions is met:

  • 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 RH circuit for 2 seconds
  • Rear occupant classification sensor RH malfunction
  • Occupant classification ECU malfunction
  • Front seat cushion spring assembly RH (Rear occupant classification sensor RH)
  • Front seat wire RH
  • Occupant classification ECU

HINT:

  • When DTC B1650/32 is detected as a result of troubleshooting the airbag system, perform troubleshooting for DTC B1783 of the occupant classification system.
  • Use the Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

  • If troubleshooting (wire harness inspection) is difficult to perform, remove the front seat RH installation bolts to see the undersurface of the seat cushion.
  • 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.

PROCEDURE

1.

CHECK FOR DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Clear any DTCs stored in the memory (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR ).

HINT:

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

(c) Turn the ignition switch off.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Using the Techstream, check for DTCs of the occupant classification ECU (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR ).

OK:

DTC B1783 is not output.

HINT:

DTCs other than DTC B1783 may be output at this time, but they are not related to this check.

OK

USE SIMULATION METHOD TO CHECK

NG

2.

CHECK CONNECTION OF CONNECTOR

(a) Turn the ignition switch off.

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

(c) Check that the connectors are properly connected to the occupant classification ECU and the rear occupant classification sensor RH.

OK:

Connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY

OK

3.

CHECK CONNECTOR

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

OK:

Connectors are not deformed or damaged.

NG

REPLACE FRONT SEAT WIRE RH

OK

4.

CHECK FRONT SEAT WIRE RH

Text in Illustration

*1

Rear Occupant Classification Sensor RH

*2

Occupant Classification ECU

*3

Front Seat Wire RH

*4

Front view of wire harness connector

(to Occupant Classification ECU)

*5

Front view of wire harness connector

(to Rear Occupant Classification Sensor RH)

*6

Connector B

*7

Connector C

*8

Service Wire

(a) Disconnect the connectors from the occupant classification ECU and the rear occupant classification sensor RH.

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

(c) Turn the ignition switch to ON, and wait for at least 60 seconds.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

X7-4 (SGD4) - Body ground

Ignition switch ON

Below 1 V

X7-6 (SVC4) - Body ground

X7-10 (SIG4) - Body ground

(e) Turn the ignition switch off.

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

(g) Using service wires, connect terminals 1 (SVC4) and 3 (SGD4), and connect terminals 2 (SIG4) and 3 (SGD4) of connector C.

NOTICE:

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

X7-6 (SVC4) - X7-4 (SGD4)

Always

Below 1 Ω

X7-10 (SIG4) - X7-4 (SGD4)

(i) Disconnect the service wires from connector C.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

X7-6 (SVC4) - X7-4 (SGD4)

Always

1 MΩ or higher

X7-10 (SIG4) - X7-4 (SGD4)

X7-6 (SVC4) - X7-10 (SIG4)

X7-4 (SGD4) - Body ground

X7-6 (SVC4) - Body ground

X7-10 (SIG4) - Body ground

NG

REPLACE FRONT SEAT WIRE RH

OK

5.

CHECK FOR DTC

(a) Connect the connectors to the occupant classification ECU and the rear occupant classification sensor RH.

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

(c) Turn the ignition switch to ON, and wait for at least 60 seconds.

(d) Clear any DTCs stored in the memory (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR ).

HINT:

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

(e) Turn the ignition switch off.

(f) Turn the ignition switch to ON, and wait for at least 60 seconds.

(g) Using the Techstream, check for DTCs of the occupant classification ECU (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR ).

OK:

DTC B1783 is not output.

HINT:

DTCs other than DTC B1783 may be output at this time, but they are not related to this check.

OK

USE SIMULATION METHOD TO CHECK

NG

6.

REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the ignition switch off.

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

(c) Replace the occupant classification ECU (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION ECU: REMOVAL ).

HINT:

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

NEXT

7.

PERFORM ZERO POINT CALIBRATION

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

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON, and wait for at least 60 seconds.

(d) Using the Techstream, perform the zero point calibration (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION ).

NG

GO TO STEP 10

OK

8.

PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION ).

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

NG

GO TO STEP 10

OK

9.

CHECK FOR DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Clear any DTCs stored in the memory (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR ).

HINT:

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

(c) Turn the ignition switch off.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Using the Techstream, check for DTCs of the occupant classification ECU (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR ).

OK:

DTC B1783 is not output.

HINT:

DTCs other than DTC B1783 may be output at this time, but they are not related to this check.

OK

END

NG

10.

REPLACE FRONT SEAT CUSHION SPRING ASSEMBLY RH

(a) Turn the ignition switch off.

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

(c) Replace the front seat cushion spring assembly RH.

  • for Manual seat (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SEAT: FRONT SEAT ASSEMBLY(for Manual Seat): REMOVAL ).
  • for Power seat (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SEAT: FRONT SEAT ASSEMBLY(for Power Seat): REMOVAL ).

HINT:

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

NEXT

11.

PERFORM ZERO POINT CALIBRATION

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

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON, and wait for at least 60 seconds.

(d) Using the Techstream, perform the zero point calibration (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION ).

NEXT

12.

PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION ).

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

NEXT

END