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DTC B2284: Brake Signal Malfunction: Procedure

  1. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Power Source Control / Data List.
    5. According to the display on the Techstream, read the Data List.
      POWER SOURCE CONTROL

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

      OK

      ON (brake pedal depressed) or OFF (brake pedal released) appears on the screen according to the stop light switch condition.

    NG → See step   2 

    OK → See step   5 

  2. CHECK HARNESS AND CONNECTOR (BATTERY - POWER MANAGEMENT CONTROL ECU) See step   1 

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

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BODY GROUND) See step   2 

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - STOP LIGHT SWITCH ASSEMBLY) 
    1. Disconnect the A35 power management control ECU connector.
    2. Disconnect the A2 stop light switch assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A35-11 (STP1) - A2-1 Always Below 1 Ω
      A35-11 (STP1) or A2-1 - Body ground Always 10 kΩ or higher
    4. Reconnect the A2 stop light switch assembly connector.
    5. Measure the voltage according to the value(s) in the table below.
      Fig 1: Checking A35 Power Management Control ECU Connector Terminals
      GTY300388Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Voltage

      Tester Connection Condition Specified Condition
      A35-11 (STP1) - Body ground Brake pedal not depressed Below 1 V
      Brake pedal depressed ([Voltage at terminal AM21 or AM22] minus 2.0 V) or higher
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   6 

  5. GO TO SFI SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  6. REPLACE POWER MANAGEMENT CONTROL ECU. Refer to  REMOVAL 
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