2017 GM Truck 6.6 Duramax DEF Problems P029B

This customer recently purchased this truck and recently its had DEF system issues. Message on the dash to Service DEF System and warning lights on. Testing leads to a failed DEF tank heater which is part of the pump assembly. I will follow-up with part 2 once I get the pump. part 2 repairs are here: 2017 GM Truck 6.6 L5P Def Pump Replac...