ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1380/64

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

DESCRIPTION

Upon receiving the hill-start assist control or 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 (for vehicle with a emergency brake signal).

DTC Code INF Code DTC Detection Condition Trouble Area
C1380/64 391 When the voltage at the +BI1 and +BI2 terminal is 8.9 V or more and the stop light control relay drive output (STPO) is ON, a signal is not input to the STP2 and EX0*1 terminal for 2 seconds or more.

  • Stop light switch

  • Stop light switch circuit

  • Stop light control relay

  • Stop light control relay circuit

  • Skid control ECU
↑ 392 When the voltage at the +BI1 and +BI2 terminal is 8.9 V or more and the stop light control relay drive output (STPO) is OFF, the signal at the STP1 terminal is different from the input signal at the STP2 for 5 seconds or more.

  • Stop light switch

  • Stop light switch circuit

  • Stop light control relay

  • Stop light control relay circuit

  • Skid control ECU

*1: w/ Emergency Brake Signal

WIRING DIAGRAM

Refer to DTC C1249/49 Click here.

INSPECTION PROCEDURE

Note

When replacing the skid control ECU, perform initialization and calibration of the linear solenoid valve 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 INTELLIGENT TESTER (STOP LIGHT SWITCH)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Select the Data List on the intelligent tester 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 intelligent tester changes according to brake pedal operation.

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

    NG

    INSPECT SKID CONTROL ECU (STP1 TERMINAL) Click here

    OK

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


    1. Select the Active Test on the intelligent tester 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*1 Stop light control relay (Emergency brake signal) Relay ON/OFF -

      *1: w/ Emergency Brake Signal

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

    3. Select the Data List on the intelligent tester Click here.

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

      ON: Relay on

      OFF: Relay off

      		 -
      Stop Light Relay Output Stop light control relay output / ON or OFF

      ON: Relay output on

      OFF: Relay output off

      		 -
      EBS Relay*1 Stop light control relay (Emergency brake signal) / ON or OFF

      ON: Relay on

      OFF: Relay off

      		 -

      *1: w/ Emergency Brake Signal

    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 is normal but stop lights do not turn on or off B

    B

    INSPECT STOP LIGHT CONTROL RELAY Click here

    A

  4. INSPECT SKID CONTROL ECU (STP2 TERMINAL)


    1. A01NDJ4E08
      Text in Illustration
      *1

      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 skid control ECU connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A90-14 (STP2) - Body ground Stop light switch ON (Brake pedal depressed) 8 to 14 V
      A90-14 (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 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 B

    B

    REPLACE SKID CONTROL ECU Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  6. INSPECT STOP LIGHT CONTROL RELAY


    1. Inspect the stop light control relay Click here.

      OK
      The stop light control relay is normal.

    NG

    REPLACE STOP LIGHT CONTROL RELAY Click here

    OK

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


    1. A01NGEOE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)
      *2

      Front view of wire harness connector

      (to Stop Light Control Relay)

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

    2. Disconnect the skid control ECU connectors and the 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
      A91-4 (STPO) - A52-9 (ACC) Always Below 1 Ω
      A91-4 (STPO) - Body ground Always 10 kΩ or higher
      A92-11 (EX0)*1 - A52-4 (ESS1)*1 Always Below 1 Ω
      A92-11 (EX0)*1 - Body ground Always 10 kΩ or higher

      *1: w/ Emergency Brake Signal


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE SKID CONTROL ECU Click here

  8. INSPECT SKID CONTROL ECU (STP1 TERMINAL)


    1. A01NFOAE02
      Text in Illustration
      *1

      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 skid control ECU connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A91-16 (STP1) - Body ground Stop light switch ON (Brake pedal depressed) 8 to 14 V
      A91-16 (STP1) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP1 CIRCUIT)

    OK

    REPLACE SKID CONTROL ECU Click here