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Home >> Toyota >> 2008 >> Matrix Base, Automatic >> Repair and Diagnosis (Single Page) >> Restraints >> Air Bag, SRS >> Supplemental Restraint System >> Occupant Classification System >> DTC B1795 Occupant Classification ECU Malfunction >> Inspection Procedure
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Inspection Procedure

  1. CHECK DTC 
    1. Turn the ignition switch to the ON position, and wait for at least 10 seconds.
    2. Check the DTCs (See DTC CHECK / CLEAR  ).

      Result: 

      A: 

      DTCs B1771 and B1795 are output. 

      B: 

      DTC B1795 is output. 

      HINT:

      Codes other than DTC B1771 and B1795 may be output at this time, but they are not related to this check.

    A: Go TO DTC B1771 

    B: Go to next step 

  2. CHECK FUSE 
    1. Measure the resistance of the ECU-B fuse.

      Standard resistance: 

      Below 1 Ω 

    NG: REPLACE FUSE 

    OK: Go to next step 

  3. CHECK WIRE HARNESS (SOURCE VOLTAGE) 
    1. Turn the ignition switch to the LOCK position.
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Disconnect the connector from the occupant classification ECU.
    4. Fig 1: Identifying Occupant Classification ECU Connector Terminals
      G05236553Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Connect the negative (-) terminal cable to the battery.
    6. Turn the ignition switch to the ON position.
    7. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED VOLTAGE CONDITION

      Tester connection Condition Specified condition
      O4-1 (+B) - Body ground Always 10 to 14 V
      O4-7 (IG) - Body ground Ignition switch ON 10 to 14 V
    8. Turn the ignition switch to the LOCK position.
    9. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED RESISTANCE CONDITION

      Tester connection Condition Specified condition
      O4-3 (GND) - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE WIRE HARNESS 

    OK: Go to next step 

  4. REPLACE OCCUPANT CLASSIFICATION ECU 
    1. Turn the ignition switch to the LOCK position.
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Replace the occupant classification ECU (See REMOVAL  ).

      HINT:

      Perform the inspection using parts from a normal vehicle if possible.

    NEXT: Go to next step 

  5. PERFORM ZERO POINT CALIBRATION 
    1. Connect the negative (-) terminal cable to the battery.
    2. Connect Techstream to the DLC3.
    3. Turn the ignition switch to the ON position.
    4. Using Techstream, perform "Zero point calibration" (See INITIALIZATION  ).

      OK: 

      The "COMPLETED" is displayed. 

    NEXT: Go to next step 

  6. PERFORM SENSITIVITY CHECK 
    1. Using Techstream, perform "Sensitivity check" (See INITIALIZATION  ).

      Standard values: 

      27 to 33 kg (59.52 to 72.75 lb) 

    NEXT : END