Toyota Sienna Quiz
Supplemental restraint system

Front Occupant Classification Sensor RH Collision Detection

In this manual: Supplemental restraint system
Introduction — 55Service specifications — 7Maintenance — 7Engine — 264U151e automatic transaxle — 108Transfer — 19Propeller shaft — 8Drive shaft — 14Differential — 16Axle — 18Suspension — 37Tire and wheel — 54Brake control — 141Parking brake — 16Steering Column — 11Power steering — 18Air conditioning — 106Supplemental restraint system — 146Seat belt — 22Theft deterrent — 14Engine immobiliser — 17Cruise control — 65Lighting — 61Wiper and washer — 13Door lock — 42Meter — 28Audio / visual — 94Navigation — 108Park assist / monitoring — 33Horn — 5Garage door opener — 42GR-FE Engine control system — 126Supplemental restraint system — 147Other system — 14Windshield / windowglass — 43Mirror — 23Instrument panel — 6Seat belt — 22Seat — 92Engine hood / door — 104Exterior — 39Interior — 5Sliding roof — 9Multiplex communication — 18Can communication — 23
24steps
~144min
4/5difficulty
Done 0 of 24

DTC B1786 Front Occupant Classification Sensor RH Collision Detection

DESCRIPTION

DTC B1786 is output when the occupant classification ECU receives a collision detection signal sent by the front occupant classification sensor RH if an accident occurs.

DTC B1786 is also output when the front seat assembly RH is subjected to a strong impact, even if an actual accident does not occur.

However, when the occupant classification ECU outputs a collision detection signal, even if the vehicle is not in a collision, DTC B1786 can be cleared by "Zero point calibration" and "Sensitivity check".

Therefore, if DTC B1786 is output, first perform "Zero point calibration" and "Sensitivity check".

DTC No.

DTC Detection Condition

Trouble Area

B1786
  • Front seat assembly RH malfunction
  • Occupant classification ECU malfunction
  • Front occupant classification sensor RH detected a large load
  • Front seat assembly RH (Front occupant classification sensor RH)
  • Occupant classification ECU

INSPECTION PROCEDURE

1 PERFORM ZERO POINT CALIBRATION

  1. Connect the intelligent tester to the DLC3.
  2. Turn the ignition switch to the ON position.
  3. Using the intelligent tester, perform "Zero point calibration" (28).

OK: "COMPLETED" is displayed

2 PERFORM SENSITIVITY CHECK

  1. Using the intelligent tester, perform "Sensitivity check" (28).

Standard value: 27 to 33 kg (59.52 to 72.75 lb

3 CHECK DTC

  1. Turn the ignition switch to the ON position.
  2. Clear the DTCs stored in the memory HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
  3. Turn the ignition switch to the LOCK position.
  4. Turn the ignition switch to the ON position.
  5. ) Check the DTCs (35).

OK: DTC B1786 is not output. HINT: Codes other than DTC B1786 may be output at this time, but they are not related to this check.

4 REPLACE FRONT SEAT ASSEMBLY RH

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
  3. Replace the front seat assembly RH ( for flat type, SE-48 for manual seat, SE-58 for power seat).

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

5 PERFORM ZERO POINT CALIBRATION

  1. Connect the negative (-) terminal cable to the battery.
  2. Connect the intelligent tester to the DLC3.
  3. Turn the ignition switch to the ON position.
  4. Using the intelligent tester, perform "Zero point calibration" (28).

OK: "COMPLETED" is displayed.

6 PERFORM SENSITIVITY CHECK

  1. Using the intelligent tester, perform "Sensitivity check" (28).

Standard value: 27 to 33 kg (59.52 to 72.75 lb)

7 CHECK DTC

  1. Turn the ignition switch to the ON position.
  2. Clear the DTCs stored in the memory.
HINT: First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
  • Turn the ignition switch to the LOCK position.
  • Turn the ignition switch to the ON position.
  • Check the DTCs (35).

    • OK: DTC B1786 is not output. HINT: Codes other than DTC B1786 may be output at this time, but they are not related to this check.

    8 REPLACE OCCUPANT CLASSIFICATION ECU

    1. Turn the ignition switch to the LOCK position.
    2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
    3. Replace the occupant classification ECU

    9 PERFORM ZERO POINT CALIBRATION

    1. Connect the negative (-) terminal cable to the battery.
    2. Connect the intelligent tester to the DLC3.
    3. Turn the ignition switch to the ON position.
    4. Using the intelligent tester, perform "Zero point calibration" (28).

    OK: "COMPLETED" is displayed.

    10 PERFORM SENSITIVITY CHECK

    1. Using the intelligent tester, perform "Sensitivity check" (28).

    Standard value: 27 to 33 kg (59.52 to 72.75 lb)

    END

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