VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1203

DTC Code DTC Name
C1203 ECM Communication Circuit Malfunction

DESCRIPTION

The circuit is used to send TRC and VSC control 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) through the CAN communication system.

for 4WD or w/ Rear Differential Lock:

The rear differential lock identification signal is sent from the 4 wheel drive control ECU to the skid control ECU (brake actuator assembly) via the CAN communication system.

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

Either of the following is detected:


  1. Engine model information sent from the ECM does not match the information stored in the skid control ECU.

  2. The rear differential lock identification signal sent from the 4 wheel drive control ECU does not match the information stored in the skid control ECU.*

  3. No system information stored in the skid control ECU.

  4. Incorrect installation of the skid control ECU, 4 wheel drive control ECU* or ECM.

  • ECM malfunction or ECM with incorrect part number installed

  • 4 wheel drive control ECU malfunction or 4 wheel drive control ECU with incorrect part number installed*

  • Skid control ECU (Brake actuator assembly)

CAUTION / NOTICE / HINT

Note

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

Click here

Tech Tips

When DTC U0114 is output together with DTC C1203, inspect and repair the trouble areas indicated by DTC U0114 first.

Click here

PROCEDURE


  1. CHECK PART NUMBER (ECM)


    1. Check that the proper ECM is installed.

      Result
      Result Proceed to
      Proper ECM is installed (for 4WD or w/ Rear Differential Lock) A
      Proper ECM is installed (except 4WD or w/o Rear Differential Lock) B
      Proper ECM are not installed C

    B

    GO TO STEP 3 Click here

    C

    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1KD-FTV: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1GD-FTV: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2GD-FTV: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2KD-FTV: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1TR-FE: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2TR-FE: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1GR-FE: Click here

    A

  2. CHECK PART NUMBER (4 WHEEL DRIVE CONTROL ECU)


    1. Check that a proper 4 wheel drive control ECU is installed.

      Result
      Proceed to
      Proper 4 wheel drive control ECU is installed
      Proper 4 wheel drive control ECU are not installed

    Proper 4 wheel drive control ECU are not installed

    REPLACE 4 WHEEL DRIVE CONTROL ECU Click here

    Proper 4 wheel drive control ECU is installed

  3. CHECK BRAKE ACTUATOR ASSEMBLY


    1. Check if the brake actuator assembly had been replaced before the DTC was recorded.

      Result
      Proceed to
      The brake actuator assembly is not replaced
      The brake actuator assembly is replaced

    The brake actuator assembly is replaced

    PERFORM INITIALIZATION AND CALIBRATION Click here

    The brake actuator assembly is not replaced

  4. RECONFIRM DTC


    1. Clear the DTC.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the ignition switch off.

    3. Check if the same DTC is recorded.

      Click here


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

    DTC C1203 is not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC C1203 is output

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  5. PERFORM INITIALIZATION AND CALIBRATION


    1. Perform initialization and calibration.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. RECONFIRM DTC


    1. Clear the DTC.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the ignition switch off.

    3. Check if the same DTC is recorded.

      Click here


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

    DTC C1203 is not output

    END

    DTC C1203 is output

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here