ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1311/11 and 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 (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

      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. C316493C35

      *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 A110 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

      A110-15 (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 A110 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.

    B
    A

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

    for LHD:Click here

    for RHD:Click here

  4. CHECK HARNESS AND CONNECTOR (BI TERMINAL)

    1. C316493C36

      *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 A110 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

      A110-14 (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. C316493C35

      *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

      A110-15 (BS) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

    for LHD:Click here

    for RHD:Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BS CIRCUIT)