Occupant Classification System (For Sedan) Diagnosis System

Vehicle Interior. Yaris. Ncp93, 131
Supplemental Restraint Systems. Yaris. Ncp93, 131

  1. SYMPTOM SIMULATION

  1. FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR

  1. PASSENGER AIRBAG ON/OFF INDICATOR CHECK

Occupant Classification System (For Sedan) -- Diagnosis System



SYMPTOM SIMULATION
HINT:
The most difficult case in troubleshooting is when no symptoms occur. In such cases, a thorough customer problem analysis must be carried out. Then the same or similar conditions and environment in which the problem occurred in the customer's vehicle should be simulated. Regardless of the technician's experience or skill, if troubleshooting proceeds without confirmation of the problem symptoms, something important is likely to be overlooked and incorrect guesses may be made at some points in the repair operation.
This leads to a standstill in troubleshooting.


    Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan).Occupant Classification System (For Sedan) Diagnosis System

  1. Vibration method: When vibration seems to be the major cause.

    HINT:
    Perform the simulation method only during the primary check period (for approximately 6 seconds after the ignition switch is turned to the on position).

    1. Slightly vibrate the part of the sensor considered to be the cause of the problem with your fingers and check whether the malfunction occurs.

      HINT:
      Shaking the relays too strongly may result in open relays.

    2. Slightly shake the connector vertically and horizontally.

    3. Slightly shake the wire harness vertically and horizontally.
      The connector joint and fulcrum of the vibration are the major areas to be checked thoroughly.

  2. Simulation method for DTC B1795: Turn the ignition switch from the lock to the on position, hold for 10 seconds, and then back to the lock position again 50 times in a row.

    HINT:
    DTC B1795 is output if the occupant classification ECU receives the ignition switch lock-on-lock signal 50 times in a row when a malfunction occurs in the power circuit for the occupant classification system.

FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR

  1. Initial check

    1. Turn the ignition switch to the on position.

    2. The passenger airbag ON/OFF indicator (ON and OFF) comes on for approximately 4 seconds, then goes off for approximately 2 seconds.

    3. Approximately 6 seconds after the ignition switch is turned to the on position, the passenger airbag ON/OFF indicator will be ON/OFF depending on the conditions listed below.

      Condition
      		ON Indicator
      		OFF Indicator
      Vacant
      		OFF
      		OFF
      Adult is seated
      		ON
      		OFF
      Child is seated
      		OFF
      		ON
      Child restraint system is set
      		OFF
      		ON
      Front passenger occupant classification system failure
      		OFF
      		ON
      HINT:

      1. The passenger airbag ON/OFF indicator operates based on the timing chart below in order to check the indicator light circuit.


        Yaris. Ncp93, 131.Supplemental Restraint Systems.Airbag System (For Sedan).Occupant Classification System (For Sedan) Diagnosis System

      2. When the occupant classification system has trouble, both the SRS warning light and the passenger airbag ON/OFF indicator (OFF) come on. In this case, check the DTCs in the airbag system first.

PASSENGER AIRBAG ON/OFF INDICATOR CHECK


    Yaris. Ncp93, 131

  1. Turn the ignition switch to ON.

  2. Check that the passenger airbag ON/OFF indicator (ON and OFF) comes on for approximately 4 seconds, then goes off for approximately 2 seconds.

    HINT:
    Refer to the table in the previous step regarding the passenger airbag ON/OFF indicator when approximately 6 seconds have elapsed after the ignition switch is turned to the on position.