U1221-00 - Lost Communication With Left Headlamp Module
NOTE:
This DTC indicates a communication issue has occurred between the Sending control module (Smart Lighting Module-Left) and the Reporting control module(s) that set this fault.
The COMMUNICATION DIAGNOSTIC PROCEDURE MUST be performed before replacing any component(s) or module(s). Perform the Perform the COMMUNICATION DIAGNOSTIC PROCEDURE. Refer to COMMUNICATION DIAGNOSTIC PROCEDURE .