Inspection Procedure

HINT:

If there is an open in the passenger side buckle switch circuit (front seat inner belt assembly circuit), the occupant classification ECU outputs DTCs. Perform troubleshooting with the "Occupant Classification System" (See DIAGNOSTIC TROUBLE CODE CHART ).

1. CHECK DTC 
   1. Check for DTCs.

      Result 

      RESULT REFERENCE
      
      

      Result	Proceed to
      DTC B1771 is not output	A
      DTC B1771 is output	B (See DTC B1771 PASSENGER SIDE BUCKLE SWITCH CIRCUIT MALFUNCTION )

   B: GO TO OCCUPANT CLASSIFICATION SYSTEM

   A: Go to next step 

2. CHECK HARNESS AND CONNECTOR (COMBINATION METER - A/C CONTROL ASSEMBLY) 
   1. Disconnect the A7 and C6 connectors.
   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      A7-38 (SEAT) - C6-24	Always	Below 1 Ω
      C6-24 - Body ground	Always	10 kΩ or higher

      Fig 1: Identifying Combination Meter And A/C Control Assembly Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: Go to next step 

3. INSPECT A/C CONTROL ASSEMBLY 
   1. Reconnect the A7 connector.
   2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      C6-24 - Body ground	Turn the ignition switch to the ON position	11 to 14 V

   Fig 2: Identifying C6 Combination Meter Terminals
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE A/C CONTROL ASSEMBLY 

   OK: Go to next step 

4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - CENTER AIRBAG SENSOR ASSEMBLY) 
   1. Disconnect the A12 connector.
   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      C6-22 - A12-13 (PBEW)	Always	Below 1 Ω
      C6-22 - Body ground	Always	10 kΩ or higher

      Fig 3: Identifying Combination Meter And Center Airbag Sensor Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: Go to next step 

5. INSPECT COMBINATION METER ASSEMBLY 
   1. Reconnect the C6 connector.
   2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      C6-22 - Body ground	Turn the ignition switch to the ON position	8 to 16 V

      Fig 4: Identifying C6 Combination Meter Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE COMBINATION METER ASSEMBLY 

   OK: Go to next step 

6. INSPECT CENTER AIRBAG SENSOR ASSEMBLY 
   1. Reconnect the A12 connector.
   2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      A12-13 (PBEW) - Body ground	Turn the ignition switch to the ON position, sit on the front passenger seat, and front passenger seat belt is unfastened	Below 1 V
      A12-13 (PBEW) - Body ground	Turn the ignition switch to the ON position, sit on the front passenger seat, and front passenger seat belt is fastened	8 to 16 V

      Fig 5: Identifying Center Airbag Sensor Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE CENTER AIRBAG SENSOR ASSEMBLY 

   OK: REPLACE COMBINATION METER ASSEMBLY