LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> GS 450h >> Repair and Diagnosis >> Engine Mechanical >> Starter >> Starting >> Smart Access System With Push-Button Start >> DTC B2284 Brake Signal Malfunction >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

  1. READ VALUE OF INTELLIGENT TESTER (STOP LIGHT SWITCH) 
    1. Check the DATA LIST for proper functioning of the stop light switch.

      Power source control ECU 

      POWER SOURCE CONTROL ECU - DATA LIST REFERENCE

      Item Measurement Item / Display (Range) Normal Condition
      STOP LAMP SW1 Stop light switch 1 / ON or OFF ON: Brake pedal depressed
      OFF: Brake pedal released

      OK: ON (brake pedal depressed) appears on screen. 

    OK: REPLACE POWER SOURCE CONTROL ECU 

    NG: GO TO Next Step 

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

      Standard resistance: Below 1 Ω 

    NG: REPLACE FUSE 

    OK: GO TO Next Step 

  3. INSPECT STOP LIGHT SWITCH 
    1. Remove the switch.
    2. Measure the resistance of the switch.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      1 - 2 Switch pin not pushed Below 1 Ω
      3 - 4 Switch pin not pushed 10 kΩ or higher
      1 - 2 Switch pin pushed 10 kΩ or higher
      3 - 4 Switch pin pushed Below 1 Ω
      Fig 1: Inspecting Stop Light Switch
      G05303639Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE STOP LIGHT SWITCH 

    OK: GO TO Next Step 

  4. CHECK WIRE HARNESS (STOP LIGHT SWITCH - POWER SOURCE CONTROL ECU AND BATTERY) 
    1. Disconnect the A35 switch connector.
    2. Disconnect the K73 ECU connector.
    3. Measure the voltage and resistance of the wire harness side connectors.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      A35-2 - Body ground 10 to 14 V

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      A35-1 - K73-1 (STP) Below 1 Ω
      A35-1 or K73-1 (STP) - Body ground 10 kΩ or higher
      4. Fig 2: Identifying A35 Switch And K73 ECU Connector
      G05303640Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: GO TO Next Step 

  5. READ VALUE OF INTELLIGENT TESTER (STOP LIGHT SWITCH) 
    1. Check the DATA LIST for proper functioning of the stop light switch.

      Rear multiplex network ECU 

      REAR MULTIPLEX NETWORK ECU - DATA LIST REFERENCE

      Item Measurement Item / Display (Range) Normal Condition
      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 POWER SOURCE CONTROL ECU 

    OK:  GO TO LIGHTING SYSTEM

scientia non olet · About LEMON Manuals