VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1380

DTC Code DTC Name
C1380 Stop Light Control Relay Malfunction

DESCRIPTION

Upon receiving the downhill assist control*1 or trailer sway control*2 operating signal from the skid control ECU (brake actuator assembly), the 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

  • When the voltage at terminal +BS is 9.5 V or higher, stop light drive output (STPO) is on and STP is OFF for 2 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

  • Skid control ECU (brake actuator assembly)

  • Stop light switch assembly

WIRING DIAGRAM

A01QS6BE01

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.

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

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Click here

    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 on 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 assembly condition 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

    CHECK HARNESS AND CONNECTOR (STP TERMINAL) Click here

    OK

  3. PERFORM ACTIVE TEST USING GTS (STOP LIGHT CONTROL RELAY)


    1. Select the Active Test on 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

      Vehicle condition: Vehicle stopped

    2. Perform the Active Test of the stop light control relay using the GTS.

    3. 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 Output Stop light control relay (STPO terminal output) ON or OFF

      ON: Output on

      OFF: Output off

      		 -

      Chassis > ABS/VSC/TRC > Active Test
      Active Test Display
      Stop Light Relay
      Data List Display
      Stop Light Relay Output

    4. Check for stop light control relay operation using the Data List and stop light operation by performing the Active Test.

      Result
      Result Proceed to
      Data List content and stop light operation are normal. A
      Data List content and stop light operation are abnormal or Data List content is normal but stop lights do not turn on or off. B

    B

    INSPECT STOP LIGHT SWITCH ASSEMBLY Click here

    A

  4. CHECK HARNESS AND CONNECTOR (STP2 TERMINAL)


    1. A01QPOVC20
      *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 A80 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
      A80-5 (STP2) - Body ground Stop light switch assembly on (Brake pedal depressed) 8 to 14 V
      A80-5 (STP2) - Body ground Stop light switch assembly off (Brake pedal released) Below 1.5 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT)

    OK

  5. RECONFIRM DTC


    1. Reconnect the A80 skid control ECU (brake actuator assembly) connector.

    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
      Proceed to
      DTC C1380 is not output.
      DTC C1380 is output.

    DTC C1380 is not output.

    USE SIMULATION METHOD TO CHECK Click here

    DTC C1380 is output.

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  6. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Turn the ignition switch off.

    2. Check the stop light control relay.

      Click here

      OK
      The stop light control relay is normal.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - STOP LIGHT SWITCH ASSEMBLY)


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

    2. Disconnect the A80 skid control ECU (brake actuator assembly) connector.

    3. Disconnect the A77 stop light switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A80-26 (STPO) -A77-4 (ACC) Always Below 1 Ω
      A80-26 (STPO) or A77-4 (ACC) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STPO CIRCUIT)

  8. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. A01QPOVC21
      *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 A80 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
      A80-35 (STP) - Body ground Stop light switch assembly on (Brake pedal depressed) 8 to 14 V
      A80-35 (STP) - Body ground Stop light switch assembly off (Brake pedal released) Below 1.5 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)