Toyota Venza Quiz
Supplemental Restraint Systems

Rear Occupant Classification Sensor RH Circuit Malfunction (B1783)

In this manual: Supplemental Restraint Systems
Introduction — 15Maintenance — 8Audio / Video — 102Garage Door Opener — 8Navigation / Multi Info Display — 81Park Assist / Monitoring — 50Brake (front) — 7Brake (rear) — 7Brake Control / Dynamic Control Systems — 79Brake System (other) — 28Parking Brake — 22Axle And Differential — 44Drive Shaft / Propeller Shaft — 24Mf1a Transfer / 4wd / Awd — 46U660e Automatic Transmission / Transaxle — 1241ar-fe Cooling — 311ar-fe Emission Control — 101ar-fe Engine Control — 1331ar-fe Engine Mechanical — 441ar-fe Fuel — 311ar-fe Intake / Exhaust — 211ar-fe Lubrication — 111ar-fe Starting — 16Cruise Control — 241ar-fe Battery / Charging — 162gr-fe Battery / Charging — 17Networking — 67Power Distribution — 8Power Assist Systems — 34Steering Column — 37Steering Gear / Linkage — 29Alignment / Handling Diagnosis — 4Front Suspension — 39Rear Suspension — 35Tire / Wheel — 4Tire Pressure Monitoring — 35Door / Hatch — 83Exterior Panels / Trim — 56Horn — 4Lighting (ext) — 89Mirror (ext) — 36Sliding Roof / Convertible — 26Window / Glass — 87Wiper / Washer — 30Door Lock — 85Heating / Air Conditioning — 82Interior Panels / Trim — 20Lighting (int) — 37Meter / Gauge / Display — 41Mirror (int) — 9Power Outlets (int) — 10Seat — 84Seat Belt — 43Supplemental Restraint Systems — 131Theft Deterrent / Keyless Entry — 155
~7min read
1special tools
DESCRIPTION

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

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

DTC No.

DTC Detecting Condition

Trouble Area

B1783
  • The occupant classification ECU receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the rear occupant classification sensor RH circuit for 2 seconds.
  • Rear occupant classification sensor RH malfunction
  • Occupant classification ECU malfunction
  • Front seat frame with adjuster assembly RH (Rear occupant classification sensor RH)
  • Occupant classification ECU
  • Front seat wire RH

HINT:

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant classification ECU. When DTC B1783 is output, perform troubleshooting for the DTC.

WIRING DIAGRAM
CAUTION / NOTICE / HINT

HINT:

  • If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to see under the seat cushion.
  • In the above case, hold the seat so that it does not fall down. Hold the seat only as necessary because holding the seat for a long period of time may cause seat rail deformation.
PROCEDURE

  1. CHECK CONNECTORS

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

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

OK:

The connectors are properly connected.

HINT:

If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

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

(e) Check that the terminals of connectors are not damaged.

OK:

The terminals are not deformed or damaged.


NG

REPLACE FRONT SEAT WIRE RH
OK

  1. CHECK FRONT SEAT WIRE RH (SHORT TO B+)

(a) Connect the cable to the negative (-) battery terminal.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

S13-4 (SGD4) - Body ground

Ignition switch ON

Below 1 V

S13-6 (SVC4) - Body ground

Ignition switch ON

Below 1 V

S13-10 (SIG4) - Body ground

Ignition switch ON

Below 1 V
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

Connector B

NG

REPLACE FRONT SEAT WIRE RH
OK

  1. CHECK FRONT SEAT WIRE RH (OPEN)

(a) Turn the ignition switch off.


(b) Disconnect the cable from the negative (-) battery terminal.

(c) Using SST, connect terminals 1 (SVC4) and 3 (SGD4), and connect terminals 2 (SIG4) and 3 (SGD4) of connector C.

NOTICE:

Do not forcibly insert SST into the terminals of the connector when connecting.

SST: 09843-18040

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

S13-6 (SVC4) - S13-4 (SGD4)

Always

Below 1 Ω

S13-10 (SIG4) - S13-4 (SGD4)

Always

Below 1 Ω
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

-

-

NG

REPLACE FRONT SEAT WIRE RH
OK

  1. CHECK FRONT SEAT WIRE RH (SHORT)

(a) Disconnect SST from connector C.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

S13-6 (SVC4) - S13-4 (SGD4)

Always

1 MΩ or higher

S13-10 (SIG4) - S13-4 (SGD4)

Always

1 MΩ or higher

S13-6 (SVC4) - S13-10 (SIG4)

Always

1 MΩ or higher
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

Connector B

NG

REPLACE FRONT SEAT WIRE RH
OK

  1. CHECK FRONT SEAT WIRE RH (SHORT TO GROUND)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

S13-4 (SGD4) - Body ground

Always

1 MΩ or higher

S13-6 (SVC4) - Body ground

Always

1 MΩ or higher

S13-10 (SIG4) - Body ground

Always

1 MΩ or higher
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

Connector B

NG

REPLACE FRONT SEAT WIRE RH
OK

  1. CHECK DTC

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

(b) Connect the cable to the negative (-) battery terminal.

(c) Turn the ignition switch to ON.

(d) Clear the DTCs stored in the occupant classification ECU (See page ).


(e) Clear the DTCs stored in the center airbag sensor assembly (See page ).


(f) Turn the ignition switch off.

(g) Turn the ignition switch to ON.

(h) Check for DTCs (See page ).


OK:

DTC B1783 is not output.

HINT:

Codes 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

  1. REPLACE OCCUPANT CLASSIFICATION ECU

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

(c) Replace the occupant classification ECU (See page ).


HINT:

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

NEXT

  1. PERFORM ZERO POINT CALIBRATION

(a) Connect the cable to the negative (-) battery terminal.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Using the Techstream, perform Zero Point Calibration (See page ).


OK:

"Zero Point Calibration is complete." is displayed.


NG

GO TO STEP 11
OK

  1. PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform Sensitivity Check (See page ).


Standard:

27 to 33 kg (59.5 to 72.8 lb)


NG

GO TO STEP 11
OK

  1. CHECK DTC

(a) Turn the ignition switch to ON.

(b) Clear the DTCs stored in the occupant classification ECU (See page ).


(c) Clear the DTCs stored in the center airbag sensor assembly (See page ).


(d) Turn the ignition switch off.

(e) Turn the ignition switch to ON.

(f) Check for DTCs (See page ).


OK:

DTC B1783 is not output.

HINT:

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


OK

END
NG

  1. REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

(c) Replace the front seat frame with adjuster assembly RH (See page for power seat or
for manual seat).


NEXT

  1. PERFORM ZERO POINT CALIBRATION

(a) Connect the cable to the negative (-) battery terminal.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Using the Techstream, perform Zero Point Calibration (See page ).


OK:

"Zero Point Calibration is complete." is displayed.

NEXT

  1. PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform Sensitivity Check (See page ).


Standard:

27 to 33 kg (59.5 to 72.8 lb)


NEXT

END

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