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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 37 (Electronically Controlled Brake System (HV) - Diagnostic Codes (08 Of 11)) >> ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model) >> DTC C1380-7E: Stop Lamp Relay Actuator Stuck On [11/2023 - ] >> Procedure

DTC C1380-7E: Stop Lamp Relay Actuator Stuck On [11/2023 - ]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK STOP LIGHT ILLUMINATION STATUS 
    1. With the brake pedal released, check the illumination status of the stop lights.

      Result

      Result Proceed to
      The stop lights are illuminated. A
      The stop lights are not illuminated. B

    Result: 

    B 

    See step  5

    Result: 

    A 

    See step  2

  2. CHECK BRAKE ACTUATOR ASSEMBLY 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

      OK

      The connector is securely connected.

      GTY928475Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 2 Skid Control ECU (Brake Actuator Assembly))
    2. Disconnect the A57 No. 2 skid control ECU (brake actuator assembly) connector.
    3. Check both the connector case and the terminals for deformation and corrosion.

      OK

      No deformation or corrosion.

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A57-11 (STP) - Body ground Stop light switch assembly off
      (Brake pedal released)      		 Below 1.5 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

    Result: 

    NG 

    See step  3

  3. CHECK STOP LIGHT SWITCH ASSEMBLY 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

      OK

      The connector is securely connected.

      GTY928475Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 2 Skid Control ECU (Brake Actuator Assembly))
    2. Disconnect the A42 stop light switch assembly connector.
    3. Check both the connector case and the terminals for deformation and corrosion.

      OK

      No deformation or corrosion.

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A57-11 (STP) - Body ground Always Below 1.5 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [12/2019 - ] 

    Result: 

    NG 

    See step  4

  4. CHECK FOR SHORT TO +B IN STP CIRCUIT 
    1. Check that there is no short to +B in the STP circuit (wire harnesses, connectors, stop lights and ECUs).

      OK

      No short to +B.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE MALFUNCTIONING PART 

  5. CHECK BRAKE ACTUATOR ASSEMBLY 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
      GTY848527Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 2 Skid Control ECU (Brake Actuator Assembly))

      OK

      The connector is securely connected.

    2. Disconnect the A57 No. 2 skid control ECU (brake actuator assembly) connector.
    3. Check both the connector case and the terminals for deformation and corrosion.

      OK

      No deformation or corrosion.

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A57-37 (STP2) - Body ground Stop light switch assembly on (Brake pedal depressed) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

    Result: 

    NG 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BRAKE ACTUATOR ASSEMBLY) 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.
      GTY909013Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Stop Light Switch Assembly)

      OK

      The connector is securely connected.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A42-3 (L) - Body ground Stop light switch assembly on (Brake pedal depressed) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    NG 

    See step  7

  7. CHECK FOR SHORT TO GROUND IN STP2 CIRCUIT 
    1. Check that there is no short to ground in the STP2 circuit (wire harnesses, connectors and ECUs)

      OK

      There is no short to ground.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [12/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE MALFUNCTIONING PART 

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