ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1311/11, C1312/12, C1313/13, C1314/14

DTC Code DTC Name
C1311/11 Open in Main Relay 1 Circuit
C1312/12 Short in Main Relay 1 Circuit
C1313/13 Open in Main Relay 2 Circuit
C1314/14 Short in Main Relay 2 Circuit

DESCRIPTION

The ABS main relay (skid control ECU interior circuit) remains ON for approximately 2 minutes after the power switch is turned OFF and the input of brake operation signals stops, and supplies power to the system to keep it ready to operate.

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

When either of the following is detected:


  1. Relay contact is off (BSO1 terminal is less than 3.5 V) for at least 0.2 seconds when +BI1 or +BI3 terminal voltage is 8.1 V or more and main relay 1 is on.

  2. +BI1 or +BI3 terminal voltage is less than 8.1 V and main relay 1 cannot be on for at least 0.2 seconds when main relay 1 is turned on (BSO1 terminal is 3.5 V or more).

  • ABS main relay (ABS MAIN1) (Skid control ECU interior circuit)

  • Harness or connector

  • Skid control ECU
C1312/12 3 Relay contact is on (BSO1 terminal is 6.5 V or more) for at least 1 second when main relay 1 is off.

  • ABS main relay (ABS MAIN1) (Skid control ECU interior circuit)

  • Harness or connector

  • Skid control ECU
C1313/13 4

When any of the following is detected:


  1. Relay contact is off (BSO2 terminal is less than 3.5 V) for at least 0.2 seconds when +BI2 or +BI4 terminal voltage is 8.1 V or more and main relay 2 is on.

  2. +BI2 or +BI4 terminal voltage is less than 8.1 V and main relay 2 cannot be on for at least 2 seconds when main relay 2 is turned on (BSO2 terminal is 3.5 V or more).

  • ABS main relay (ABS MAIN2) (Skid control ECU interior circuit)

  • Harness or connector

  • Skid control ECU
C1314/14 6 Relay contact is on (BSO2 terminal is 6.5 V or more) for at least 1 second when main relay 2 is off.

  • ABS main relay (ABS MAIN2) (Skid control ECU interior circuit)

  • Harness or connector

  • Skid control ECU

WIRING DIAGRAM

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

INSPECTION PROCEDURE

Note

When replacing the skid control ECU, perform the following operations:


  • Initialization of linear solenoid valve and calibration Click here

  • Yaw rate and acceleration sensor zero point calibration Click here

PROCEDURE


  1. INSPECT FUSE (ABS MAIN1, ABS MAIN2 AND ABS MAIN3)


    1. Remove the ABS MAIN1, ABS MAIN2 and ABS MAIN3 fuses from the engine room No. 2 junction block/relay block.

    2. Measure the resistance of the fuses.

      Standard resistance
      Tester Connection Condition Specified Condition
      ABS MAIN1 fuse Always Below 1 Ω
      ABS MAIN2 fuse Always Below 1 Ω
      ABS MAIN3 fuse Always Below 1 Ω

    NG

    REPLACE FUSE

    OK

  2. CHECK TERMINAL VOLTAGE (+BI1, +BI2, +BI3, +BI4)


    1. A01H1MKE21

      Disconnect the A19 and A21 ECU connectors.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      A19-43 (+BI1) - Body ground Always 11 to 14 V
      A21-38 (+BI2) - Body ground Always 11 to 14 V
      A19-29 (+BI3) - Body ground Always 11 to 14 V
      A21-22 (+BI4) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. RECONFIRM DTC


    1. Clear the DTC Click here.

    2. Turn the power switch ON (IG).

    3. Check if the same DTCs are recorded Click here.

      Tech Tips

      Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

      Result
      Condition Proceed to
      DTCs (C1311/11, C1312/12, C1313/13 and C1314/14) are not output A
      DTCs (C1311/11, C1312/12, C1313/13 and C1314/14) are output for LHD B
      for RHD C

    B

    REPLACE SKID CONTROL ECU Click here

    C

    REPLACE SKID CONTROL ECU Click here

    A

    USE SIMULATION METHOD TO CHECK Click here