VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1380

DTC Code DTC Name
C1380 Stop Light Control Relay Malfunction

DESCRIPTION

Upon receiving the hill-start assist control 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

Either condition is met:

  • When the voltage at the IG1 terminal is between 9.5 V or more and the stop light control relay drive output (STP0) is on, a signal is not input to the STP2 terminal for 2 seconds or more.

  • When the voltage at the IG1 terminal is between 9.5 V or more and the stop light control relay drive output (STP0) is off, the signal at the STP terminal is different from the input signal at the STP2 terminal for 5 seconds or more.

  • Wire harness or connector

  • Stop light control relay (STOP LP)

  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

C358205E01

CAUTION / NOTICE / HINT

Note:

  • When replacing the skid control ECU (brake actuator assembly), perform system variant learning.

    Click here

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

PROCEDURE

  1. CHECK DTC

    1. Check if the same DTC is output.

      Click here

      Chassis > ABS/VSC/TRC > Trouble Codes

      Result

      Result

      Proceed to

      DTC C1380 is output.

      A

      DTCs C1249, C1425, C1426 and/or C1380 are output.

      B
      Tip:

      When C1249, C1425 and/or C1426 are output together with C1380 inspect and repair the trouble areas indicated by C1249, C1425 and/or C1426 first.

      Click here

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

    Click hereClick hereClick here

    A

  2. 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

      Result

      Illumination Condition

      Brake pedal depressed.

      On

      Brake pedal released.

      Off

    Result

    Proceed to

    OK

    NG
    NG

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT)

    Click hereClick here

    OK

  3. 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

      Type

      Normal Condition

      Diagnostic Note

      Stop Light SW

      Stop light switch

      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

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

      Relay ON/OFF

      Stop lights come on

    2. Perform the Active Test of the stop light control relay (STOP LP) using the GTS.

      Chassis > ABS/VSC/TRC > Active Test

      Tester Display

      Stop Light Relay

    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 (STOP LP) output

      ON or OFF

      ON: Relay output on (Stop light on)

      OFF: Relay output off (Stop light off)

      -

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      Stop Light Relay Output

    4. Check for stop light control relay (STOP LP) operation using the Data List and stop light operation by performing an 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 ASSEMBLYClick here

    A

  5. CHECK HARNESS AND CONNECTOR (STP, STP2 TERMINAL)

    1. C238832C11

      *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 A97 skid control ECU (brake actuator assembly) connector.

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

    5. Check the operation of the stop light when operating it with the GTS.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A97-22 (STP2) - Body ground

      Stop light switch assembly ON (Brake pedal depressed)

      11 to 14 V

      A97-22 (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

    OK

  6. RECONFIRM DTC

    1. Reconnect the A97 skid control ECU (brake actuator assembly) connector.

    2. Clear the DTCs.

      Click here

      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the ignition switch to ON.

    4. Perform a road test.

    5. 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
    A

    CHECK USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick hereClick here

  7. 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

  8. CHECK HARNESS AND CONNECTOR (STPO TERMINAL)

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

    2. Disconnect the A97 skid control ECU (brake actuator assembly) connector.

    3. Disconnect the A176 stop light switch assembly connector.

    4. Turn the ignition switch to ON.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A97-3 (STPO) - A176-4 (ACC)

      Always

      Below 1 Ω

      A97-3 (STPO) or A176-4 (ACC) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP0 CIRCUIT)

  9. CHECK HARNESS AND CONNECTOR (STP TERMINAL)

    1. C238832C05

      *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 A97 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

      A97-30 (STP) - Body ground

      Stop light switch ON (Brake pedal depressed)

      11 to 14 V*

      A97-30 (STP) - Body ground

      Stop light switch OFF (Brake pedal released)

      Below 1.5 V
      Tip:

      *: The standard voltage value varies depending on the +BS terminal voltage value. The standard voltage is 85% of the +BS terminal voltage.

      Result

      Proceed to

      OK

      NG
    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)