DTC    C1203    ECM Communication Circuit Malfunction


DESCRIPTION

The circuit is used to send TRAC and VSC control information from the skid control ECU (brake actuator assembly) to the ECM, and engine control information from the ECM or main body ECU (multiplex network body ECU) to the skid control ECU (brake actuator assembly) through the CAN communication system.

DTC No.
DTC Detection Condition
Trouble Area
C1203
Engine, drive source and destination variations that are sent from the ECM or main body ECU (multiplex network body ECU) do not match the ones of the skid control ECU (brake actuator assembly).
  1. ECM
  2. Main body ECU (Multiplex network body ECU)
  3. Skid control ECU (Brake actuator assembly)

INSPECTION PROCEDURE

1.CHECK PART NUMBER (ECM AND BRAKE ACTUATOR ASSEMBLY)

  1. Check that the proper ECM is installed.

Result 
Result
Proceed to
Proper ECM is installed
A
Proper ECM are not installed
B


B
REPLACE ECM (Click here)
A


2.CHECK PART NUMBER (MAIN BODY ECU AND BRAKE ACTUATOR ASSEMBLY)

  1. Check that the proper main body ECU (multiplex network body ECU) is installed.

    Result 
    Result
    		Proceed to
    Proper ECU is installed
    		A
    Proper ECU is not installed
    		B


B
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (Click here)
A


3.CHECK BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU)

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

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


B
Go to step 5
A


4.RECONFIRM DTC

  1. Clear the DTC (Click here).

  1. Check if the same DTC is recorded (Click here).

Result 
Result
Proceed to
DTC is not output
A
DTC is output
B


B
REPLACE BRAKE ACTUATOR ASSEMBLY (Click here)
A

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (Click here)  

5.PERFORM INITIALIZATION AND CALIBRATION

  1. Perform initialization and calibration (Click here).


NEXT


6.RECONFIRM DTC

  1. Clear the DTC (Click here).

  1. Check if the same DTC is recorded (Click here).

Result 
Result
Proceed to
DTC is not output
A
DTC is output
B


B
REPLACE BRAKE ACTUATOR ASSEMBLY (Click here)
A

END