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Home >> Lexus >> 2004 >> RX 330 AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 522 (Cruise Control) >> Dynamic Laser Cruise Control System >> DTC P0571: Brake Switch "A" Circuit >> Inspection Procedure
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Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.
  1. READ VALUE ON INTELLIGENT TESTER 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch on, and turn the intelligent tester main switch on.
    3. Check the DATA LIST for proper functioning of the stop light switch.

      ECM (Cruise control): 

      NORMAL CONDITION TABLE

      Item Measurement Item/Display (Range) Normal Condition Diagnostic Note
      STP LIGHT SW M Stop light switch signal (Main CPU)/ON or OFF ON: Brake pedal depressed
      OFF: Brake pedal released      		 -

      OK: 

      When the brake pedal is operated, the display changes as shown above. 

    OK: REPLACE ECM 

    NG: Go to Next Step 

  2. INSPECT STOP LIGHT SWITCH 
    1. Disconnect the stop light switch connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION REFERENCE TABLE

      Tester Connection Switch Condition Specified Condition
      1 - 2 Switch pin not pushed 10 kΩ or higher
      3 - 4 Switch pin not pushed Below 1 Ω
      1 - 2 Switch pin pushed Below 1 Ω
      3 - 4 Switch pin pushed 10 kΩ or higher
      Fig 1: Identifying Stop Light Switch
      G05273664Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE STOP LIGHT SWITCH 

    OK: Go to Next Step 

  3. CHECK WIRE HARNESS (STOP LIGHT SWITCH - BATTERY) 
    1. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION REFERENCE TABLE

      Tester Connection Condition Specified Condition
      S13-2 - Body ground Always 10 to 14 V
      S13-3 - Body ground Ignition switch on 10 to 14 V
      Fig 2: Identifying S13 Connector Terminals
      G05273619Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  4. CHECK ECM 
    1. Reconnect the stop light switch connector.
    2. Disconnect the E5 connector from the ECM.
    3. Turn the ignition switch on.
    4. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION REFERENCE TABLE

      Tester Connection Brake Pedal Condition Specified Condition
      E5-15 (STP) - Body ground Depressed 10 to 14 V
      E5-15 (STP) - Body ground Released Below 1 V
      E5-16 (ST1-) - Body ground Depressed Below 1 V
      E5-16 (ST1-) - Body ground Released 10 to 14 V
      Fig 3: Identifying E5 Connector Terminals
      G05273621Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH - ECM) 

    OK: REPLACE ECM 

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