DTC C1203: ECM Communication Circuit Malfunction [08/2015 - 08/2019]: Procedure

1. Check if any DTC is recorded for the engine control system (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
   RESULT
   
   

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

Result: 

A 

REPLACE ECM 

(Refer to REMOVAL [08/2015 - ] )

Result: 

B 

GO TO ENGINE CONTROL SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - ] )