LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2019 >> LS 500 Base, AWD >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Electronically Controlled Brake System (W/ Vacuum Brake Booster) - Diagnostic Codes (2 Of 4) >> ELECTRONICALLY CONTROLLED BRAKE SYSTEM (w/ Vacuum Brake Booster) >> DTC C1380-7E: Stop Lamp Relay Actuator Stuck On [09/2018 - 10/2020] >> Procedure

DTC C1380-7E: Stop Lamp Relay Actuator Stuck On [09/2018 - 10/2020]: Procedure

  1. CHECK FOR DTCs (POWER INTEGRATION SYSTEM) 
    1. Check for DTCs.

      Refer to DTC CHECK / CLEAR [12/2017 - 10/2023]

      Body Electrical > Power Integration No. 3 > Trouble Codes 

      HINT: 

      If there is a malfunction in the No. 3 semiconductor power integration ECU, integration relay system DTCs may also have been detected. Check the integration relay system first.

      Result

      Result Proceed to
      Power integration system DTCs are not output A
      Power integration system DTCs are output B

    Result: 

    B 

    GO TO POWER INTEGRATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 10/2023] 

    Result: 

    A 

    See step  2

  2. READ VALUE USING TECHSTREAM (RADAR CRUISE INPUT SIGNAL, STOP LIGHT OUTPUT SIGNAL, STOP LIGHT RELAY AND STPO) 
    1. Using the Techstream, check the Data List "Radar Cruise Input Signal", "Stop Light Output Signal", "Stop Light Relay" and "STPO" with the brake pedal operated.

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Body Electrical > Power Integration No. 3 > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Radar Cruise Input Signal Radar cruise operation condition OFF / ON ON: Radar cruise system operates
      OFF: Radar cruise system does not operate      		 -
      Stop Light Output Signal Stop light output condition OFF / ON ON: Stop light is on
      OFF: Stop light is off      		 -

      Body Electrical > Power Integration No. 3 > Data List 

      Tester Display
      Radar Cruise Input Signal
      Stop Light Output Signal

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU OFF
      ON: No. 3 semiconductor power Integration ECU ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2
      STPO No. 3 semiconductor power Integration ECU (STPO terminal output) OFF / ON OFF: No. 3 semiconductor power integration ECU off (Stop light off)
      ON: No. 3 semiconductor power integration ECU on (Stop light blinks)      		 HINT: 
      When STPO is ON, the No. 3 semiconductor power integration ECU turns ON and the stop lights illuminate

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
      STPO

      OK

      Brake pedal operation Data List Display Condition
      No. 3 Semiconductor Power Integration ECU Skid control ECU (brake actuator assembly)
      Radar Cruise Input Signal Stop Light Output Signal Stop Light Relay STPO
      Brake pedal released OFF OFF OFF OFF

      Result

      Brake pedal operation Data List Display Condition Result
      No. 3 Semiconductor Power Integration ECU Skid control ECU (brake actuator assembly)
      Radar Cruise Input Signal Stop Light Output Signal Stop Light Relay STPO
      Brake pedal released ON ON ON ON A
      ON ON ON OFF B
      OFF ON ON OFF C
      OFF OFF ON OFF D

    Result: 

    A 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [09/2018 - 10/2020] 

    Result: 

    C 

    REPLACE NO. 3 SEMICONDUCTOR POWER INTEGRATION ECU. Refer to  REMOVAL [09/2018 - 10/2020] 

    Result: 

    D 

    See step  4

    Result: 

    B 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - NO. 3 SEMICONDUCTOR POWER INTEGRATION ECU) 
    1. Disconnect the A9 skid control ECU (brake actuator assembly) connector.
    2. Disconnect the L111 No. 3 semiconductor power integration ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A9-26 (STPO) or L111-14 (ACC) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NO. 3 SEMICONDUCTOR POWER INTEGRATION ECU. Refer to  REMOVAL [09/2018 - 10/2020] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  4. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Disconnect the L86 rear light lens and body LH connector.
    2. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    3. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    B 

    See step  6

    Result: 

    A 

    See step  5

  5. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Connect the L86 rear light lens and body LH connector.
    2. Disconnect the rear light LED LH connector.

      HINT: 

      Refer to DISASSEMBLY [12/2017 - ]

    3. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    4. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    A 

    REPLACE REAR LIGHT LED LH. Refer to  DISASSEMBLY [12/2017 - ] 

    Result: 

    B 

    REPLACE REAR LIGHT LENS AND BODY LH. Refer to  DISASSEMBLY [12/2017 - ] 

  6. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Disconnect the L90 rear light lens and body RH connector.
    2. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    3. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    B 

    See step  8

    Result: 

    A 

    See step  7

  7. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Connect the L90 rear light lens and body RH connector.
    2. Disconnect the rear light LED RH connector.

      HINT: 

      Refer to DISASSEMBLY [12/2017 - ]

    3. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    4. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    A 

    REPLACE REAR LIGHT LED RH. Refer to  DISASSEMBLY [12/2017 - ] 

    Result: 

    B 

    REPLACE REAR LIGHT LENS AND BODY RH. Refer to  DISASSEMBLY [12/2017 - ] 

  8. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Disconnect the L82 rear combination light assembly LH connector.
    2. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    3. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    B 

    See step  10

    Result: 

    A 

    See step  9

  9. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Connect the L82 rear combination light assembly LH connector.
    2. Disconnect the rear combination light LED LH connector.

      HINT: 

      Refer to DISASSEMBLY [12/2017 - ]

    3. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    4. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    A 

    REPLACE REAR COMBINATION LIGHT LED LH. Refer to  DISASSEMBLY [12/2017 - ] 

    Result: 

    B 

    REPLACE REAR COMBINATION LIGHT LENS AND BODY LH. Refer to  DISASSEMBLY [12/2017 - ] 

  10. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Disconnect the L81 rear combination light assembly RH connector.
    2. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    3. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    B 

    See step  12

    Result: 

    A 

    See step  11

  11. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Connect the L81 rear combination light assembly RH connector.
    2. Disconnect the rear combination light LED RH connector.

      HINT: 

      Refer to DISASSEMBLY [12/2017 - ]

    3. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    4. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    A 

    REPLACE REAR COMBINATION LIGHT LED RH. Refer to  DISASSEMBLY [12/2017 - ] 

    Result: 

    B 

    REPLACE REAR COMBINATION LIGHT LENS AND BODY RH. Refer to  DISASSEMBLY [12/2017 - ] 

  12. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Disconnect the A center stop light assembly connector.
    2. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    3. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    A 

    REPLACE CENTER STOP LIGHT ASSEMBLY. Refer to  REMOVAL [12/2017 - ] 

    Result: 

    B 

    See step  13

  13. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Disconnect the L71 center stop light wire connector.
    2. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    3. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    A 

    REPLACE CENTER STOP LAIGHT WIRE. Refer to  REMOVAL [12/2017 - ] 

    Result: 

    B 

    See step  14

  14. READ VALUE USING TECHSTREAM (STOP LIGHT RELAY) 
    1. Disconnect the L111 No. 3 semiconductor power integration ECU connector.
    2. According to the display on the Techstream, read the Data List "Stop Light Relay".

      Refer to DATA LIST / ACTIVE TEST [09/2018 - 10/2023]

      Chassis > Brake > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF / ON OFF: No. 3 semiconductor power Integration ECU (STP2 terminal input) OFF
      ON: No. 3 semiconductor power Integration ECU (STP2 terminal input) ON      		 HINT: 
      The stop light state is determined using the voltage at terminal STP2

      Chassis > Brake > Data List 

      Tester Display
      Stop Light Relay
    3. Check the Techstream display condition of the Stop Light Relay.

      Result

      Result Proceed to
      Display of the Data List remains OFF. A
      Display of the Data List remains ON. B

    Result: 

    A 

    REPLACE NO. 3 SEMICONDUCTOR POWER INTEGRATION ECU. Refer to  REMOVAL [09/2018 - 10/2020] 

    Result: 

    B 

    See step  15

  15. CHECK HARNESS AND CONNECTOR ((STP2 TERMINAL) 
    1. Disconnect the A9 skid control ECU (brake actuator assembly) connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A9-5 (STP2) - Body ground Engine switch on (IG) 0 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [09/2018 - 10/2020] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

scientia non olet · About LEMON Manuals