A1 CAN receive frame E2SCR (Dosing,Exh gas flow,Exh gas temp,Error Supression, Heater, Long Term failure) - SAE J1939 Check for CAN receive signal - P0600 Serial Communication Link
If Steering Not Working,Hydraulic suction filter plugged.Improper tire inflation.Steering linkage needs lubrication.Excessive play in steering. See your John Deere Dealer.