ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1380/64

DTC Code DTC Name
C1380/64 Stop Light Control Relay Malfunction

DESCRIPTION

Upon receiving the dynamic radar cruise control system operating signal from the skid control ECU, the relay contact turns on and the stop light comes on.

Upon receiving the emergency brake signal operating signal from the skid control ECU, the relay contact turns on and the stop light blinks.

DTC Code INF Code DTC Detection Condition Trouble Area
C1380/64 761 When the voltage at the IG1 terminal is 9.5 V or more and the stop light control relay drive output (STP0) is ON, a signal is not input to the STP2 and EXO terminal for 2 seconds or more.

  • Stop light switch

  • Stop light switch circuit

  • Stop light control relay

  • Stop light control relay circuit

  • Brake booster with master cylinder (Skid control ECU)
↑ 762 When the voltage at the IG1 terminal is 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 and EXO for 5 seconds or more.

  • Stop light switch

  • Stop light switch circuit

  • Stop light control relay

  • Stop light control relay circuit

  • Brake booster with master cylinder (Skid control ECU)

WIRING DIAGRAM

Refer to DTC C1249/49 Click here.

INSPECTION PROCEDURE

Note

When replacing the brake booster with master cylinder (skid control ECU), perform initialization, calibration of the linear solenoid valve and emergency brake signal learning Click here.

Tech Tips

When C1249/49 is output together with C1380/64, inspect and repair the trouble areas indicated by C1249/49 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

    INSPECT STOP LIGHT CIRCUIT Click here

    OK

  2. READ VALUE USING GTS (STOP LIGHT SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Select the Data List on the GTS Click here.

      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

      		 -

    4. 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

    INSPECT SKID CONTROL ECU (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.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Stop Light Relay Stop light control relay Relay ON/OFF Stop lights come on
      EBS Relay Stop light control relay (Emergency brake signal) Relay ON/OFF

      • Hazard warning switch OFF

      • Stop light switch ON

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

    3. Select the Data List on the GTS Click here.

      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: Relay output on

      OFF: Relay output off

      		 -
      EBS Relay Stop light control relay (Emergency brake signal) / ON or OFF

      ON: Relay on

      OFF: Relay off

      • Hazard warning switch OFF

      • Stop light switch ON

    4. Check for stop light control relay operation using 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 CONTROL ECU ASSEMBLY Click here

    A

  4. INSPECT SKID CONTROL ECU (STP2 TERMINAL)


    1. A0044BAE80
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Turn the power switch off.

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

    3. Disconnect the A57 skid control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A57-6 (STP2) - Body ground Stop light switch ON (Brake pedal depressed) 11 to 14 V
      A57-6 (STP2) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT)

    OK

  5. RECONFIRM DTC


    1. Reconnect the A57 skid control ECU connector.

    2. Clear the DTCs Click here.

    3. Turn the power switch on (READY).

    4. Perform a road test.

    5. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTC (C1380/64) is not output A
      DTC (C1380/64) is output (for LHD) B
      DTC (C1380/64) is output (for RHD) C

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

    C

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  6. INSPECT STOP LIGHT CONTROL ECU ASSEMBLY


    1. Inspect the stop light control ECU assembly Click here.

      OK
      The stop light control ECU assembly is normal.

    NG

    REPLACE STOP LIGHT CONTROL ECU ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - STOP LIGHT CONTROL ECU ASSEMBLY)


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

    2. Disconnect the A57 skid control ECU connector.

    3. Disconnect the A28 stop light control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A57-3 (STP0) - A28-9 (ACC) Always Below 1 Ω
      A57-3 (STP0) - Body ground Always 10 kΩ or higher
      A57-21 (EXO) - A28-4 (ESS1) Always Below 1 Ω
      A57-21 (EXO) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

  8. INSPECT SKID CONTROL ECU (STP TERMINAL)


    1. A0044BAE76
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Turn the power switch off.

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

    3. Disconnect the A57 skid control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A57-33 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 11 to 14 V
      A57-33 (STP) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here