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DTC B2284: Brake Signal Malfunction: Procedure

  1. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH) 
    1. Use the Data List to check if the stop light switch is functioning properly.
      MAIN BODY

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light SW Stop light switch/ON or OFF ON: Brake pedal depressed
      OFF: Brake pedal released      		 -

      OK

      ON (brake pedal depressed) appears on screen.

    NG → REPLACE MAIN BODY ECU 

    OK: Go to next step 

  2. INSPECT FUSE (STOP) 
    1. Remove the STOP fuse from the main body ECU.
    2. Measure the resistance of the fuse.

      Standard resistance

      Tester Connection Condition Specified Condition
      STOP fuse Always Below 1 Ω

    NG → REPLACE FUSE 

    OK: Go to next step 

  3. INSPECT STOP LIGHT SWITCH 
    1. Remove the stop light switch. Refer to REMOVAL .
      Fig 1: Identifying Connector Terminals Of Stop Light Switch
      GTY288269Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Switch Condition Specified Condition
      1 - 2 Stop light switch pin not pushed Below 1 Ω
      3 - 4 Stop light switch pin not pushed 10 kΩ or higher
      1 - 2 Stop light switch pin pushed 10 kΩ or higher
      3 - 4 Stop light switch pin pushed Below 1 Ω

    NG → See step   6 

    OK: Go to next step 

  4. CHECK WIRE HARNESS (STOP LIGHT SWITCH - MAIN BODY ECU AND BATTERY) 
    Fig 2: Identifying A35 Stop Light Switch And DH Main Body ECU Connectors
    GTY288256Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A35 stop light switch connector.
    2. Disconnect the DH main body ECU connector.
    3. Measure the voltage and resistance according to the value(s) in the table below.

      Standard voltage

      Tester Connection Condition Specified Condition
      A35-2 - Body ground Always 11 to 14 V

      Standard resistance

      Tester Connection Condition Specified Condition
      A35-1 - DH-15 (STP) Always Below 1 Ω
      A35-1 or DH-15 (STP) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  5. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH) 
    1. Use the Data List to check if the stop light switch is functioning properly.
      BODY NO. 4

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light Switch Stop light switch/ON or OFF ON: Brake pedal depressed
      OFF: Brake pedal released      		 -

      OK

      ON (brake pedal depressed) appears on screen.

    NG → REPLACE MAIN BODY ECU 

    OK → See step   7 

  6. REPLACE STOP LIGHT SWITCH. Refer to  REMOVAL 
  7. GO TO LIGHTING SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
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