Last Modified: 11-29-2007 1.6 C
Service Category: Vehicle Interior Section: Supplemental Restraint Systems
Model Year: 2008 Model: Sequoia Doc ID: RM00000157V00AX
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DESCRIPTION (2008 Sequoia)

DTC

B1783

Rear Occupant Classification Sensor RH Circuit Malfunction

DESCRIPTION

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

DTC B1783 is stored when a malfunction is detected in the rear occupant detection 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 detection sensor RH circuit for 2 seconds
  • Rear occupant detection sensor RH malfunction
  • Occupant classification ECU malfunction
  • Front seat assembly RH (Rear occupant detection sensor RH)
  • Front seat wire 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



INSPECTION PROCEDURE

NOTICE:

After the ignition switch is turned off, the navigation system requires approximately 90 seconds to record various types of memory and settings. As a result, after turning the ignition switch off, wait 90 seconds or more before disconnecting the cable from the negative (-) battery terminal.

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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR (2008 Sequoia) .

HINT:

  • First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
  • 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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR (2008 Sequoia) .

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

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 detection sensor RH.

OK:

Connectors are properly connected.

OK

3.

CHECK CONNECTOR

(a) Check that the connectors (on the occupant classification ECU side and rear occupant detection sensor RH side) are not damaged INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE (2008 Sequoia) .

OK:

Connectors are not deformed or damaged.

OK

4.

CHECK FRONT SEAT WIRE RH



(a) Disconnect the connectors from the occupant classification ECU and the rear occupant detection 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

W1-4 (SGD4) - Body ground

Ignition switch ON

Below 1 V

W1-6 (SVC4) - Body ground

W1-10 (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

W1-6 (SVC4) - W1-4 (SGD4)

Always

Below 1 Ω

W1-10 (SIG4) - W1-4 (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

W1-6 (SVC4) - W1-4 (SGD4)

Always

1 MΩ or higher

W1-10 (SIG4) - W1-4 (SGD4)

W1-6 (SVC4) - W1-10 (SIG4)

W1-4 (SGD4) - Body ground

W1-6 (SVC4) - Body ground

W1-10 (SIG4) - Body ground

OK

5.

CHECK FOR DTC

(a) Connect the connectors to the occupant classification ECU and the rear occupant detection 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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR (2008 Sequoia) .

HINT:

  • First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
  • 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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR (2008 Sequoia) .

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

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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION ECU: REMOVAL (2008 Sequoia) .

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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION (2008 Sequoia) .

OK

8.

PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION (2008 Sequoia) .

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR (2008 Sequoia) .

HINT:

  • First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
  • 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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: DTC CHECK / CLEAR (2008 Sequoia) .

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

10.

REPLACE FRONT SEAT 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 assembly RH.

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 SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION (2008 Sequoia) .

NEXT

12.

PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: INITIALIZATION (2008 Sequoia) .

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

NEXT