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 (master cylinder solenoid), the stop light control relay contact turns on and the stop light comes on.

DTC Code DTC Detection Condition Trouble Area
C1380

Either condition is met:


  1. When the voltage at the IG1 terminal is between 11 and 14 V and the stop light control relay drive output (STPO) is on, a signal is not input to the STP2 terminal for 5 seconds or more.

  2. When the voltage at the IG1 terminal is between 11 and 14 V and the stop light control relay drive output (STPO) is off, the signal at the STP terminal is different from the input signal at the STP2 terminal for 5 seconds or more.

  • STOP fuse

  • Stop light switch circuit

  • Stop light control relay assembly

  • Stop light control relay assembly circuit

  • Skid control ECU (Master cylinder solenoid)

WIRING DIAGRAM

A01EO1UE01

INSPECTION PROCEDURE

Note


  • After replacing the master cylinder solenoid, perform zero point calibration and store the system information Click here.

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

Tech Tips

When DTC C1425 is output together with DTC C1380, inspect and repair the trouble areas indicated by DTC C1425 first 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

    NG

    CHECK HARNESS AND CONNECTOR (+B, GND TERMINAL) Click here

    OK

  2. READ VALUE USING GTS (STOP LIGHT SW)


    1. Turn the engine switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

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

      ON: Brake pedal depressed

      OFF: Brake pedal released

      		 -

    6. Check that the stop light switch condition observed on the GTS changes according to brake pedal operation.

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

    NG

    CHECK HARNESS AND CONNECTOR (STP TERMINAL) Click here

    OK

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


    1. Turn the engine switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Stop Light Relay Stop light control relay Relay ON/OFF Observe the stop lights (do not come on for 2 to 5 seconds).

    6. While performing the Active Test, check the illumination condition of the stop lights and "Stop Light Relay Output" in the Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light Relay Output Stop light control relay output/ ON or OFF

      ON: Stop light control relay on (Stop lights on)

      OFF: Stop light control relay off (Stop lights off)

      		 -
      Result
      Result Proceed to
      When Active Test performed, Data List item changes between ON and OFF and stop lights turn on and off A
      When Active Test performed, Data List item changes between ON and OFF, but stop lights do not turn on B

    B

    CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT CONTROL RELAY) Click here

    A

  4. CHECK HARNESS AND CONNECTOR (STP2 TERMINAL)


    1. Disconnect the skid control ECU (master cylinder solenoid) connector.

    2. A01ENMBE70
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU [Master Cylinder Solenoid])

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-45 (STP2) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Start the engine.

    3. Perform a road test.

    4. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output (for LHD) B
      DTC is output (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  6. CHECK HARNESS AND CONNECTOR (+B, GND TERMINAL)


    1. Disconnect the Stop light control relay connector.

    2. A01ERABE10
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Control Relay Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A58-6 (+B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-8 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. Disconnect the Stop light control relay connector.

    2. A01ERABE11
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Control Relay Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A58-5 (STP) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - SKID CONTROL ECU)


    1. Disconnect the A58 Stop light control relay connector.

    2. Disconnect the A24 skid control ECU (master cylinder solenoid) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-1 (OUT) - A24-45 (STP2) Always Below 1 Ω
      A58-1 (OUT) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE STOP LIGHT CONTROL RELAY ASSEMBLY

  9. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. Disconnect the skid control ECU (master cylinder solenoid) connector.

    2. A01ENMBE71
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU [Master Cylinder Solenoid])

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-7 (STP) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V
      Result
      Result Proceed to
      NG A
      OK (for LHD) B
      OK (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT CONTROL RELAY)


    1. Disconnect the A24 skid control ECU (master cylinder solenoid) connector.

    2. Disconnect the A58 Stop light control relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A24-16 (STPO) - A58-9 (ACC) Always Below 1 Ω
      A24-16 (STPO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT CONTROL RELAY)


    1. Disconnect the A24 skid control ECU (master cylinder solenoid) connector.

    2. Disconnect the A58 Stop light control relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A24-45 (STP2) - A58-1 (OUT) Always Below 1 Ω
      A24-45 (STP2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE STOP LIGHT CONTROL RELAY ASSEMBLY