Toyota RAV4 manuals

Toyota Sienna Service Manual: Front Occupant Classification Sensor LH Collision Detection

DTC B1785 Front Occupant Classification Sensor LH Collision Detection

DESCRIPTION

DTC B1785 is output when the occupant classification ECU receives a collision detection signal sent by the front occupant classification sensor LH if an accident occurs.

DTC B1785 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 B1785 can be cleared by "Zero point calibration" and "Sensitivity check".

Therefore, if DTC B1785 is output, first perform "Zero point calibration" and "Sensitivity check".

DTC No.

DTC Detecting Condition

Trouble Area

B1785

  • Front seat assembly RH malfunction
  • Occupant classification ECU malfunction
  • Front occupant classification sensor LH detected a large load
  • Front seat assembly RH (Front occupant classification sensor LH)
  • 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 B1785 is not output. HINT: Codes other than DTC B1785 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.

  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 B1785 is not output. HINT: Codes other than DTC B1785 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

Rear Occupant Classification Sensor RH Circuit Malfunction
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 occup ...

Front Occupant Classification Sensor RH Collision Detection
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 ...

Other materials:

Removal
1. DISCHARGE REFRIGERANT FROM REFRIGERATION SYSTEM SST 07110-58060 (07117-58080, 07117-58090, 07117-78050, 07117-88060, 07117-88070, 07117-88080) HINT: See page AC-172. 2. REMOVE REAR DOOR SCUFF PLATE RH (See page IR-7) 3. REMOVE BACK DOOR SCUFF PLATE (See page IR- 8) 4. REMOVE QUARTER TR ...

Unlock Warning Switch Circuit
DESCRIPTION The unlock warning switch detects if the key is in the ignition key cylinder. The unlock warning switch turns on when the key is inserted into the ignition key cylinder and turns off when the key is removed from the cylinder. The body ECU is connected to the unlock warning swit ...

Intake Air Temperature Circuit/ Intake Air Temperature Circuit Low Input/ Intake Air Temperature Circuit High Input
DTC P0110 Intake Air Temperature Circuit DTC P0112 Intake Air Temperature Circuit Low Input DTC P0113 Intake Air Temperature Circuit High Input DESCRIPTION The Intake Air Temperature (IAT) sensor, mounted on the Mass Air Flow (MAF) meter, monitors the IAT. The IAT sensor has a built-in ther ...

В© 2011-2019 Copyright www.tsienna.net