Supplemental Restraint Systems. Dtc B1786 Front Occupant Classification Sensor Rh Collision Detection

Vehicle Interior. Yaris. Ncp93, 131

Supplemental Restraint Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ZERO POINT CALIBRATION

PERFORM SENSITIVITY CHECK

CHECK DTC

REPLACE FRONT SEAT ASSEMBLY RH

PERFORM ZERO POINT CALIBRATION

PERFORM SENSITIVITY CHECK

CHECK DTC

REPLACE OCCUPANT CLASSIFICATION ECU

PERFORM ZERO POINT CALIBRATION

PERFORM SENSITIVITY CHECK

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 when 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 front occupant classification sensor RH outputs a collision detection signal, even if the vehicle is not in a collision, DTC B1786 can be cleared by performing the zero point calibration and sensitivity check.
Therefore, when DTC B1786 is output, first perform the 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 detects large load	Occupant classification ECU Front seat assembly RH (Front occupant classification sensor RH)

WIRING DIAGRAM

YARIS_NCP93 RM0000010V803CX.html.

INSPECTION PROCEDURE

1.PERFORM ZERO POINT CALIBRATION

Connect the Techstream to the DLC3.

Turn the ignition switch to the on position.

Using the Techstream, perform the zero point calibration (YARIS_NCP93 RM0000010VN06EX.html).
OK:
COMPLETED is displayed.

Go to step 4

OK

2.PERFORM SENSITIVITY CHECK

Using the Techstream, perform the sensitivity check (YARIS_NCP93 RM0000010VN06EX.html).
1. Confirm that nothing is placed on the passenger seat.
2. Confirm that the beginning sensor reading is within the standard range.
  Standard range:
  -3.2 to 3.2 kg (-7 to 7 lb)
3. Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
4. Confirm that the sensitivity is within the standard range.
  Standard range:
  27 to 33 kg (59.52 to 72.75 lb)
  HINT:
  When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).

Go to step 4

OK

3.CHECK DTC

Turn the ignition switch to the on position.

Clear the DTCs stored in the memory (YARIS_NCP93 RM0000010VK06DX.html).
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 (YARIS_NCP93 RM0000010VK06DX.html).
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.

USE SIMULATION METHOD TO CHECK

NG

4.REPLACE FRONT SEAT ASSEMBLY RH

Turn the ignition switch to the lock position.

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

Replace the front seat assembly RH (YARIS_NCP93 RM000002AK600CX.html ).
HINT:
Perform the inspection using parts from a normal vehicle if possible.

NEXT

5.PERFORM ZERO POINT CALIBRATION

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

Connect the Techstream to the DLC3.

Turn the ignition switch to the on position.

Using the Techstream, perform the zero point calibration (YARIS_NCP93 RM0000010VN06EX.html).
OK:
COMPLETED is displayed.

Go to step 8

OK

6.PERFORM SENSITIVITY CHECK

Using the Techstream, perform the sensitivity check (YARIS_NCP93 RM0000010VN06EX.html).
1. Confirm that nothing is placed on the passenger seat.
2. Confirm that the beginning sensor reading is within the standard range.
  Standard range:
  -3.2 to 3.2 kg (-7 to 7 lb)
3. Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
4. Confirm that the sensitivity is within the standard range.
  Standard range:
  27 to 33 kg (59.52 to 72.75 lb)
  HINT:
  When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).

Go to step 8

OK

7.CHECK DTC

Turn the ignition switch to the on position.

Clear the DTCs stored in the memory (YARIS_NCP93 RM0000010VK06DX.html).
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 (YARIS_NCP93 RM0000010VK06DX.html).
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.

USE SIMULATION METHOD TO CHECK

NG

8.REPLACE OCCUPANT CLASSIFICATION ECU

Turn the ignition switch to the lock position.

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

Replace the occupant classification ECU (YARIS_NCP93 RM0000012DU00KX.html).

NEXT

9.PERFORM ZERO POINT CALIBRATION

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

Connect the Techstream to the DLC3.

Turn the ignition switch to the on position.

Using the Techstream, perform the zero point calibration (YARIS_NCP93 RM0000010VN06EX.html).
OK:
COMPLETED is displayed.

NEXT

10.PERFORM SENSITIVITY CHECK

Using the Techstream, perform the sensitivity check (YARIS_NCP93 RM0000010VK06DX.html).
1. Confirm that nothing is placed on the passenger seat.
2. Confirm that the beginning sensor reading is within the standard range.
  Standard range:
  -3.2 to 3.2 kg (-7 to 7 lb)
3. Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
4. Confirm that the sensitivity is within the standard range.
  Standard range:
  27 to 33 kg (59.52 to 72.75 lb)
  HINT:
  When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).

END