Description Doser Pump Unit Assy Tata PART NUMBER 278949200105 COMATIBLE TATA TRUCK BS6 MODELS TATA ULTRA LPT 712 1012 1112 LP 410 412 710 407 GOLD 912 SFC 610 1212 510 812 Common faults & fault codes related to Tata BS6 Doser Pump Unit (278949200105): DEF dosing pump not building pressure – Fault code: P20E8 (Low reductant pressure) Pump electrical/open circuit issue – Fault code: P20EE / P20E9 (Dosing control malfunction). Blocked or crystallized DEF in pump – Fault code: P204F (Reductant system performance). Internal pump failure or overheating – Fault code: P21CA / P21CB (Reductant pump control). Communication or sensor feedback error – Fault code: P2063 / P2064 (Reductant level/pressure signal).