Diagnosis System

1. Check the DLC3 (See HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS ).

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 the environment in which the problem occurred in the customer's vehicle should be simulated No matter how experienced or skilled a technician may be, if he proceeds to troubleshooting without confirming the problem symptoms, he will likely overlook something important and make a wrong guess at some points in the repair operation This leads to a standstill in troubleshooting

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

   HINT

   Perform the simulation method only during the primary check period of approximately 6 seconds after the engine switch is turned on (IG).

   1. Slightly vibrate the part of the sensor considered to be the problem cause 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

      Fig 1: Shaking Connector Vertically And Horizontally

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Initial check.
   1. Turn the engine switch on (IG)
   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 engine switch is turned on (IG), the passenger airbag ON/OFF indicator will show ON or OFF depending on the conditions listed below.
      FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR
      
      

      Front Passenger Seat Condition	Passenger Airbag ON/OFF Indicator		SRS Warning Light
      	ON Indicator	OFF Indicator
      Vacant	OFF	OFF	OFF
      Adult is seated	ON	OFF	OFF
      Child is seated	OFF	ON	OFF
      Child restraint system is set	OFF	ON	OFF
      Front passenger occupant classification failure	OFF	ON	ON

      HINT

      • The passenger airbag ON/OFF indicator is based on the timing chart below in order to check the indicator light circuit
      • 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
        Fig 2: Identifying Passenger Airbag ON/OFF Indicator Position

        Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Turn the engine switch on (IG)
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 the engine switch is turned on (IG) and approximately 6 seconds pass.

   Fig 3: Identifying Passenger Airbag ON/OFF Indicator

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002