VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1380

DTC Code DTC Name
C1380 Stop Light Control Relay Malfunction

DESCRIPTION

Upon receiving the downhill assist control (for AWD) or dynamic radar cruise control (w/ dynamic radar cruise control) operating signal from the skid control ECU (brake actuator assembly), the stop light control relay contact turns on and the stop light comes on.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1380 Stop Light Control Relay Malfunction

Either of the following is detected:


  • When the voltage at terminal +BS is 9.5 V or higher, stop light drive output (STPO) is ON and STP2 is OFF for 5 seconds or more.

  • When the voltage at terminal +BS is 9.5 V or higher, stop light drive output (STPO) is OFF, and input signals for STP and STP2 differ for 5 seconds or more.


  • Wire harness or connector

  • Stop light switch assembly

  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

Refer to DTC C1425

Click here

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.

    Click here

  • Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips

When C1425 and/or C1426 is output together with C1380, inspect and repair the trouble areas indicated by C1425 and/or C1426 first.

for C1425: Click here

for C1426: Click here

PROCEDURE


  1. CHECK STOP LIGHT OPERATION


    1. Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

      OK
      Condition Illumination Condition
      Brake pedal depressed. On
      Brake pedal released. Off
      Result
      Proceed to
      OK
      NG

    NG
    OK
  2. READ VALUE USING GTS (STOP LIGHT SWITCH ASSEMBLY)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Select the Data List using the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light SW Stop light switch assembly ON or OFF

      ON: Brake pedal depressed

      OFF: Brake pedal released

      -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      Stop Light SW
    4. Check that the stop light switch display observed on the GTS changes according to brake pedal operation.

      OK
      The GTS displays ON or OFF according to brake pedal operation.
      Result
      Proceed to
      OK
      NG

    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (STP2 TERMINAL)


    1. A002AHOC19
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the ignition switch off.

    2. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    3. Disconnect the A86 skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A86-5 (STP2) - Body ground Stop light switch assembly on (Brake pedal depressed) 8 to 14 V
      A86-5 (STP2) - Body ground Stop light switch assembly off (Brake pedal released) Below 1.5 V
      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. PERFORM ACTIVE TEST USING GTS (STOP LIGHT CONTROL RELAY)


    1. Reconnect the A86 skid control ECU (brake actuator assembly) connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Select the Active Test using the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Stop Light Relay Stop light control relay Relay ON/OFF Stop lights come on

      Chassis > ABS/VSC/TRC > Active Test
      Tester Display
      Stop Light Relay
    5. Select the Data List on the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Relay Stop light control relay ON or OFF

      ON: Stop light control relay on

      OFF: Stop light control relay off

      w/ Downhill assist control or dynamic radar cruise control

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      Stop Light Relay
    6. Check the operating condition of the stop light control relay when operating it using the GTS.

      Result
      Proceed to
      OK
      NG

    NG
    OK
  5. RECONFIRM DTC


    1. Turn the ignition switch off.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs
    3. Turn the ignition switch off.

    4. Start the engine.

    5. Perform a road test.

    6. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1380 is not output. A
      DTC C1380 is output. B

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

      Click here


    A
    B
  6. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Turn the ignition switch off.

    2. Check the stop light switch assembly.

      Click here

      OK
      The stop light switch assembly is normal.
      Result
      Proceed to
      OK
      NG

    NG
    OK
  7. CHECK HARNESS AND CONNECTOR (STPO TERMINAL)


    1. A002AHOC20
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the A86 skid control ECU (brake actuator assembly) connector.

    3. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A86-26 (STPO) - Body ground Ignition switch ON 11 to 14 V

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

      Click here

      Result
      Proceed to
      OK
      NG

    OK
    NG
  8. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. A002AHOC16
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the ignition switch off.

    2. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    3. Disconnect the A86 skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A86-35 (STP) - Body ground Stop light switch assembly on (Brake pedal depressed) 8 to 14 V
      A86-35 (STP) - Body ground Stop light switch assembly off (Brake pedal released) Below 1.5 V

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

      Click here

      Result
      Proceed to
      OK
      NG

    OK
    NG