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DTC B2284: Brake Signal Malfunction [07/2015 - ]: Procedure

  1. READ VALUE USING TECHSTREAM 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Power Source Control / Data List.
    5. Read the Data List according to the display on the Techstream.
      POWER SOURCE CONTROL

      Tester Display Measurement Item/Range Normal Condition Specified Condition
      Stop Light Switch1 Stop light switch1/ON or OFF ON: Brake pedal depressed
      OFF: Brake pedal released
      • Use this item to determine whether the stop light switch is malfunctioning.
      • The hybrid control system cannot be started when this item is OFF.
      • When this item is malfunctioning, the hybrid control system can be started by pressing and holding the power switch for a certain period of time.

      OK

      The Techstream display changes correctly in response to the brake pedal operation.

    Result:  OK

    OK 

    GO TO BRAKE CONTROL SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) 

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [07/2015 - ]

    Result:  NG

    NG 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE) 

    See step  1

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR IN CIRCUIT CONNECTED TO POWER SOURCE 

    Result:  OK

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (GROUND) 

    See step  2

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY) 
    1. Disconnect the A28 stop light switch assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A70-18 (STP1) - A28-2 (L) Always Below 1 Ω
      A70-18 (STP1) or A28-2 (L) - Body ground Always 10 kΩ or higher
    3. Reconnect the A28 stop light switch assembly connector.
    4. Disconnect the A70 certification ECU (Smart key ECU assembly) connector.
      GTY644655Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A70-18 (STP1) - Body ground Brake pedal released 1 V or less
      Brake pedal depressed 9 V or higher
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Certification ECU (Smart Key ECU Assembly))

    Result:  OK

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

    Refer to REMOVAL [07/2015 - ]

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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