This light, a Driver Information Center (DIC) Message, and a chime come on when there is an issue with the DEF.
If the DEF issue has not been corrected, the light will continue to flash. The vehicle's speed may also be limited. See Diesel Exhaust Fluid.
Valve Rocker Arm Cleaning and Inspection Valvetrain Valve Actuating Assembly Rocker Arms
Inspect the camshaft follower roller-(1) for thefollowing:Flat spotsExcessive scoring and pittingEnsure the roller spins freelyInspect the camshaft follower valve tiparea-(2).Inspect the camshaft follower stationary hydraulic lashadjuster (SHLA) pivot area-(3).Replace the camshaft follower or follow ...