VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1203

DTC Code DTC Name
C1203 ECM Communication Circuit Malfunction

DESCRIPTION

This circuit is used to send TRC and VSC operation information from the skid control ECU (brake actuator assembly) to the ECM, and engine control information from the ECM to the skid control ECU (brake actuator assembly) via CAN communication.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
C1203 ECM Communication Circuit Malfunction

Either of the following is detected:


  • Engine, drivetrain and destination information sent from the ECM does not match the information stored in the skid control ECU (brake actuatorassembly).

  • No stored information for destination.

  • Incorrect installation of the skid control ECU or ECM.

  • An incorrect ECU is installed.

  • Skid control ECU (brake actuator assembly)

 -
C1203 DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2 Pattern 3
Diagnosis Condition - - - -
Malfunction Status Engine information sent from the ECM does not match the information stored in the skid control ECU(brake actuator assembly) ○ - -
No stored information for destination - ○ -
Incorrect installation of the skid control ECU or ECM - - ○
Detection Time - - -
Number of Trips 1 trip 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.

    Click here

  • Before replacing the ECM, refer to Service Bulletin.

PROCEDURE


  1. CHECK PART NUMBER (ECM)


    1. Check that the proper ECM is installed.

      OK
      Proper ECM is installed.

    2. Check if the ECM was replaced before the DTC was stored.

      OK
      ECM was not replaced.
      Result
      Result Proceed to
      OK A
      NG (A proper ECM is not installed and/or the ECM was replaced.) B

    B

    REPLACE ECM Click here

    A

  2. CHECK PART NUMBER (BRAKE ACTUATOR ASSEMBLY)


    1. Check that a proper skid control ECU (brake actuator assembly) is installed.

      OK
      Proper skid control ECU (brake actuator assembly) is installed.

    2. Check if the skid control ECU (brake actuator assembly) had been replaced before the DTC was stored.

      OK
      Skid control ECU (brake actuator assembly) had not been replaced.
      Result
      Result Proceed to
      OK A
      NG (The skid control ECU (brake actuator assembly) had been replaced.) B
      NG for LHD : (A proper skid control ECU (brake actuator assembly) is not installed.) C
      NG for RHD : (A proper skid control ECU (brake actuator assembly) is not installed.) D

    B

    PERFORM ZERO POINT CALIBRATION AND STORE SYSTEM INFORMATION Click here

    C

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    D

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

  3. CLEAR AND STORE SYSTEM INFORMATION


    1. Clear the system information.

      Click here

    2. Store the system information.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  4. 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 is not output. A
      DTC C1203 is output. (for LHD) B
      DTC C1203 is output. (for RHD) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    C

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here