ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1311/11, C1312/12

DTC Code DTC Name
C1311/11 Open in Main Relay 1 Circuit
C1312/12 Short in Main Relay 1 Circuit

DESCRIPTION

The ABS main relay supplies power to the changeover solenoid and the linear solenoid.

The ABS main relay remains on for approximately 2 minutes after the power switch is turned off (lock) and the input of brake pedal operation signals stops, and supplies power to the system to keep it ready to operate.

DTC Code INF Code DTC Detection Condition Trouble Area
C1311/11 1

Either of the following is detected:


  1. When the power switch is on (ready):

    The ABS main relay contact is not turned ON (BS terminal voltage 3.5 V or more) for 0.2 seconds or more when ABS main relay ON is requested while IG1 terminal voltage is 9.5 V or more.

  2. When the power switch is off (lock):

    The ABS main relay contact is not turned ON (BS terminal voltage 3.5 V or more) for 0.2 seconds or more when ABS main relay ON is requested.

  • Open or short in ABS main relay circuit

  • Brake booster with master cylinder (Skid control ECU)
C1312/12 2 The ABS main relay contact is turned ON (BS terminal voltage 3.5 V or more) for 4.5 seconds or more when ABS main relay OFF is requested from the ECU.

  • Short in ABS main relay circuit

  • ABS main relay internal stuck

  • Brake booster with master cylinder (Skid control ECU)

WIRING DIAGRAM

Refer to DTCs C1241/41 and C1242/42 Click here.

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (ABS MAIN RELAY)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Select the Active Test on the GTS Click here.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      ECB* Main Relay ABS main relay Relay ON/OFF -

      *: Electronically Controlled Brake System

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

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      ECB* Main Relay ABS main relay / ON or OFF

      ON: Relay on

      OFF: Relay off

      		 -

      *: Electronically Controlled Brake System

    5. Check the operating condition of the ABS main relay when operating it with the GTS.

      Result
      Result Proceed to
      ABS main relay in the Data List turns ON/OFF using the Active Test A
      ABS main relay in the Data List does not change using the Active Test B

    B

    INSPECT SKID CONTROL ECU (BI TERMINAL) Click here

    A

  2. INSPECT SKID CONTROL ECU (BS TERMINAL)


    1. A005APOE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Turn the power switch off (lock).

    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 Condition Specified Condition
      A58-15 (BS) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)

    OK

  3. RECONFIRM DTC


    1. Reconnect the skid control ECU connector.

    2. Clear the DTCs Click here.

    3. Turn the power switch on (IG).

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

      Result
      Result Proceed to
      DTCs (C1311/11and C1312/12) are not output A
      DTCs (C1311/11 and/or C1312/12) are output (for LHD) B
      DTCs (C1311/11 and/or C1312/12) are output (for RHD) C

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

    C

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

  4. INSPECT SKID CONTROL ECU (BI TERMINAL)


    1. A005A2QE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

      Turn the power switch off (lock).

    2. Check that the ABS MAIN NO. 1 (20 A) and ABS MAIN NO. 2 (7.5 A) fuses are normal.

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

    4. Disconnect the skid control ECU connector.

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

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BI CIRCUIT)

    OK

  5. INSPECT SKID CONTROL ECU (BS TERMINAL)


    1. A005APOE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A58-15 (BS) - Body ground Always 11 to 14 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)