DTC C1203: ECM Communication Circuit Malfunction [11/2016 - ]: Procedure

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

Result:

B 

REPLACE ECM 

for 1AR-FE: Refer to REMOVAL [12/2013 - ]

for 2GR-FKS: Refer to REMOVAL [11/2016 - ]

Result:

A 

Go to next step 

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 recorded.

   OK

   Skid control ECU (brake actuator assembly) had not been replaced.

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

Result:

B 

PERFORM ZERO POINT CALIBRATION AND STORE SYSTEM INFORMATION OF YAW RATE AND ACCELERATION SENSOR. 

Refer to CALIBRATION [11/2016 - ]

Result:

C 

REPLACE BRAKE ACTUATOR ASSEMBLY. 

Refer to REMOVAL [11/2016 - ]

Result:

A 

Go to next step 

1. Clear the system information.

   Refer to CALIBRATION [11/2016 - ]

2. Store the system information.

   Refer to CALIBRATION [11/2016 - ]

NEXT 

Go to next step 

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

2. Turn the ignition switch off.
3. Turn the ignition switch to ON.
4. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result	Proceed to
   DTC C1203 is not output.	A
   DTC C1203 is output.	B

Result:

A 

USE SIMULATION METHOD TO CHECK. 

Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2016 - ]

Result:

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. 

Refer to REMOVAL [11/2016 - ]