Q21-6209-001
Diesel Exhaust Fluid Quality Sensor · PACCAR
AdBlue and DEF system components for SCR aftertreatment: tank, pump, dosing unit, sensors, failure patterns and replacement checks
The AdBlue, or DEF, system stores, delivers and doses the aqueous urea solution that reduces nitrogen oxides to nitrogen and water in the SCR catalyst; the system comprises a tank with level and quality sensors, an electrically driven delivery pump with pressure control, a dosing unit at the exhaust system, and heated lines that prevent the solution from freezing in cold weather.
The components are matched to the engine family, tank size and vehicle or machine range; the dosing unit and pump differ in delivery rate and software depending on engine power and emission stage, and the quality sensor checks the required urea concentration of 32.5 per cent (AUS 32). The assignment list on this page comes from official US EPA certification documentation.
A failed delivery pump or a blocked dosing unit produces fault messages and, once a grace period has elapsed, a reduction in engine power; crystallised urea residue in the lines and dosing valve results from extended standstill or leaks; the quality sensor reports a fault when water or an incorrect concentration is present in the tank.
Replacement is matched by part number rather than shape, since the tank, pump and dosing unit differ by vehicle variant; check lines, connectors and seals for crystalline deposits; after replacing the pump, dosing unit or quality sensor, a learning drive or basic setting in the control unit is often required. Price and availability are not covered on this page.
Fits these engines (60)
| Paccar MX-11 250 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 265 | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 265 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 265 E R | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 265E (F & E) | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 265R (Refuse) | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 280 | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 280 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 300 (DDE) | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 300 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 300 E R | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 300R (Refuse) | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 310 | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 310 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 320 | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 320 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 320 MT | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 320E (F & E) | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 321 E MT | Heavy-Duty-Straßenmotoren |
| Paccar MX-11 330 | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_355hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_355hp_FE | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_355hp_R | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_375hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_402hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_402hp_R | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_416hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_429hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_429hp_FE | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_429hp_MT1650 | Heavy-Duty-Straßenmotoren |
| Paccar MX-11_443hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 303 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 303 E HT | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 303 MT | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 304 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 320 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 320 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 321 E MT | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 340 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 340 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 340MT1550-1750 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 340MT1650-1850 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 341 E MT | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 360 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 360 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 360E Del Assy | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 380 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 380 E | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 380E (F & E) | Heavy-Duty-Straßenmotoren |
| Paccar MX-13 380E Del Assy | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_406hp_MT1750 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_429hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_456hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_456hp_MT1750 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_456hp_MT1850 | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_483hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_483hp_DA | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_510hp | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_510hp_DA | Heavy-Duty-Straßenmotoren |
| Paccar MX-13_510hp_FE | Heavy-Duty-Straßenmotoren |
Excludes price and availability — those come from the supplier.