ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1203/95

DTC Code DTC Name
C1203/95 ECM Communication Circuit Malfunction

DESCRIPTION

The circuit is used to send TRC and VSC information from the skid control ECU to the VGRS ECU (front steering control ECU) and DRS ECU (rear steering control ECU), variable gear ratio steering system information from the VGRS ECU (front steering control ECU) to the skid control ECU, and dynamic rear steering system information from the DRS ECU (rear steering control ECU) to the skid control ECU via the CAN communication system.

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1203/95 ECM Communication Circuit Malfunction -

Any of the following is detected:

1. The information stored in the skid control ECU assembly does not match with the information about whether or not there is a VGRS ECU (front steering control ECU).

2. The information stored in the skid control ECU assembly does not match with the information about whether or not there is a DRS ECU (rear steering control ECU).

3. An improper skid control ECU assembly is installed.

4. The skid control assembly is malfunctioning.

  • VGRS ECU (front steering control ECU) with wrong part number installed or ECU malfunctioning

  • DRS ECU (rear steering control ECU) with wrong part number installed or ECU malfunctioning

  • Skid control ECU assembly

 Electronically controlled brake system DTC
DTC No. Brake warning light / yellow (minor malfunction) code ABS warning light code Slip indicator light code Brake hold standby indicator light code
C1203 95 42 45 21

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU assembly, perform initialization and calibration of the linear solenoid valve.

Click here

PROCEDURE


  1. PERFORM INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE


    1. Perform initialization and calibration of the linear solenoid valve.

      Click here


      Chassis > ABS/VSC/TRC > Utility
      Tester Display
      ECB Utility

      • ECB: Electronically Controlled Brake System

      Tech Tips

      Before performing initialization and calibration of the linear solenoid valve, DTC C1203/95 will be output.

      Result
      Proceed to
      NEXT

    NEXT

  2. RECONFIRM DTC


    1. Turn the engine switch off.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the engine switch off.

    4. Turn the engine switch on (IG).

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1203/95 is output. (w/ variable gear ratio steering system) A
      DTC C1203/95 is output. (w/o variable gear ratio steering system) B
      DTC C1203/95 is not output. C

    B

    CHECK PART NUMBER (SKID CONTROL ECU ASSEMBLY) Click here

    C

    END

    A

  3. CHECK PART NUMBER (VGRS ECU (FRONT STEERING CONTROL ECU))


    1. For vehicles with the variable gear ratio steering system, check that the part number of the installed VGRS ECU (front steering control ECU) is correct. For vehicles without the variable gear ratio steering system, make sure that a VGRS ECU (front steering control ECU) is not installed.

      OK
      The presence or absence of the VGRS ECU (front steering control ECU) appropriately matches the specifications of the vehicle.

    2. Check if the VGRS ECU (front steering control ECU) had been replaced before the DTC was stored.

      OK
      ECU had not been replaced.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE VGRS ECU (FRONT STEERING CONTROL ECU) Click here

    OK

  4. CHECK PART NUMBER (DRS ECU (REAR STEERING CONTROL ECU))


    1. For vehicles with the variable gear ratio steering system, check that the part number of the installed DRS ECU (rear steering control ECU) is correct. For vehicles without the variable gear ratio steering system, make sure that a DRS ECU (rear steering control ECU) is not installed.

      OK
      The presence or absence of the DRS ECU (rear steering control ECU) appropriately matches the specifications of the vehicle.

    2. Check if the DRS ECU (rear steering control ECU) had been replaced before the DTC was stored.

      OK
      ECU had not been replaced.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE DRS ECU (REAR STEERING CONTROL ECU) Click here

    OK

  5. CHECK PART NUMBER (SKID CONTROL ECU ASSEMBLY)


    1. Check that the proper skid control ECU assembly is installed.

      OK
      Proper skid control ECU assembly is installed.

    2. Check if the skid control ECU assembly was replaced before the DTC was recorded.

      OK
      The skid control ECU assembly was not replaced.
      Result
      Result Proceed to
      OK A
      NG (A proper skid control ECU assembly is not installed.) B
      NG (The skid control ECU assembly was replaced.) C

    B

    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here

    C

    CHECK INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE Click here

    A

  6. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the engine switch off.

    3. Turn the engine switch on (IG).

    4. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1203/95 is not output. A
      DTC C1203/95 is output. B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here

  7. CHECK INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE


    1. After replacing the skid control ECU assembly, check that the initialization and calibration of the linear solenoid valve is being performed.

      OK
      Initialization and calibration of the linear solenoid valve is being performed.
      Result
      Proceed to
      OK
      NG

    NG

    PERFORM INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE Click here

    OK

  8. CHECK ZERO POINT CALIBRATION OF YAW RATE SENSOR


    1. After replacing the skid control ECU assembly, check that the zero point calibration of the yaw rate sensor is being performed.

      OK
      Zero point calibration of the yaw rate sensor is being performed.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here

    NG

    PERFORM ZERO POINT CALIBRATION OF YAW RATE SENSOR Click here