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

1. Check if an engine control system DTC is output (Refer to DTC CHECK / CLEAR [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 - ] )