25-003-17 REV. A

Flash: Dosing Control Unit (DCU) Diagnostic and System Improvements This bulletin involves reprogramming the DCU with the latest available software and if necessary replacing the unit. Some customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, a technician may find the following Diagnostic Trouble Codes (DTCs):P207F - Reductant Quality Performance. P202C - Reductant Tank Heater Control Circuit High. P203B - Reductant Level Sensor 1 Circuit Performance.