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

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DTC Code DTC Name
C1311/11 Open in Main Relay 1 Circuit
C1312/12 Short in Main Relay 1 Circuit
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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 and the input of brake pedal operation signals stops, and supplies power to the system to keep it ready to operate.

DTC No. 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:

    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

  • Skid control ECU (Brake booster with master cylinder assembly)
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

  • Skid control ECU (Brake booster with master cylinder assembly)
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WIRING DIAGRAM

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

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CAUTION / NOTICE / HINT

Note:

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

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

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PROCEDURE


  1. Click here

    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).

      Table 1. 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).

      Table 2. 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 that the condition of the ABS main relay observed on the GTS changes according to GTS operation.

      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

  2. Click here

    CHECK HARNESS AND CONNECTOR (BS TERMINAL)


    1. A00095ZE01

      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 A24 skid control ECU (brake booster with master cylinder assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-15 (BS) - Body ground Always 11 to 14 V
      Table 3. Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)

  3. Click here

    RECONFIRM DTC


    1. Reconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.

    2. Clear the DTCs (Click here).

    3. Turn the power switch on (IG).

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

      Result
      Result Proceed to
      DTCs C1311/11 and 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

      USE SIMULATION METHOD TO CHECK (Click here)

    • B

      REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (Click here)

    • C

      REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (Click here)

  4. Click here

    CHECK HARNESS AND CONNECTOR (BI TERMINAL)


    1. A00048ME01

      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 A24 skid control ECU (brake booster with master cylinder assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-14 (BI) - Body ground Always 11 to 14 V
      Table 4. Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (BI CIRCUIT)

  5. Click here

    CHECK HARNESS AND CONNECTOR (BS TERMINAL)


    1. A00095ZE01

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-15 (BS) - Body ground Always 11 to 14 V
      Table 5. Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    • A

      REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (Click here)

    • B

      REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (Click here)

    • C

      REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)