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 and the input of brake pedal operation signals stops, and supplies power to the system to keep it ready to operate.

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1311/11 Open in Main Relay 1 Circuit 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 the 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 the ABS main relay ON is requested.

  • Open or short in ABS main relay circuit

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

 Electronically controlled brake system DTC
C1312/12 Short in Main Relay 1 Circuit 2 The ABS main relay contact is turned ON (BS terminal voltage 3.5 V or more) for 4.5 seconds or more when the 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)

 Electronically controlled brake system DTC

WIRING DIAGRAM

Refer to DTCs C1241/41 and C1242/42.

Click here

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 procedure.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (ECB 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


      Chassis > ABS/VSC/TRC > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      ECB Main Relay ABS main relay Relay ON/OFF ECB: Electronically Controlled Brake System

      Chassis > ABS/VSC/TRC > Active Test
      Tester Display
      ECB Main Relay

    4. Select the Data List on the GTS.

      Click here


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

      ON: Relay on

      OFF: Relay off

      		 ECB: Electronically Controlled Brake System

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      ECB Main Relay

    5. Check that the condition of the ABS main relay observed on the GTS changes according to the 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

    B

    CHECK HARNESS AND CONNECTOR (BI TERMINAL) Click here

    A

  2. CHECK HARNESS AND CONNECTOR (BS TERMINAL)


    1. A01MK1FC11
      *a

      Front view of wire harness connector

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

      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 A63 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
      A63-15 (BS) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)

    OK

  3. RECONFIRM DTC


    1. Reconnect the A63 skid control ECU (brake booster with master cylinder assembly) connector.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the power switch off.

    4. Turn the power switch on (IG).

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTCs C1311/11 and C1312/12 are not output. A
      DTCs C1311/11 and/or C1312/12 are output (for RHD). B
      DTCs C1311/11 and/or C1312/12 are output (for LHD). 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. CHECK HARNESS AND CONNECTOR (BI TERMINAL)


    1. A01MK1FC13
      *a

      Front view of wire harness connector

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

      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 A63 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
      A63-14 (BI) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BI CIRCUIT)

    OK

  5. CHECK HARNESS AND CONNECTOR (BS TERMINAL)


    1. A01MK1FC12
      *a

      Front view of wire harness connector

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A63-15 (BS) - Body ground Always 11 to 14 V
      Result
      Result Proceed to
      OK (for RHD) A
      OK (for LHD) 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)