AdBlue Feed Pump (Feed Unit/Metering Pump)
SCR & AdBlue System
Function of the AdBlue Feed Pump in the SCR System
The AdBlue feed pump (also known as a feed unit, tank pump, or metering pump) is the heart of the AdBlue supply system in the SCR exhaust system of modern diesel vehicles. As the central component between the tank and the fuel injection unit, it delivers the urea solution at the exact operating pressure required through the entire piping system, thereby ensuring a continuous supply for catalytic nitrogen oxide reduction.
Reliable even at low fluid levels, under varying load conditions, and at extreme outside temperatures.
Since AdBlue freezes at temperatures below -11 °C and tends to form crystals when exposed to heat, the feed pump is designed to be particularly durable: An integrated heating element keeps the fluid pumpable even in winter temperatures, while high-quality materials in the pump housing and seals are designed to withstand the corrosive effects of the urea solution over the long term.
Reliability and Common Causes of Failure
Typical causes of failure include a defective pump motor due to wear and tear, crystal formation on pumping elements and valves, clogged filters or intake screens, leaky seals resulting in pressure loss, and damage to the heating element, which can cause the system to freeze in cold weather. Poor-quality or contaminated AdBlue can also significantly shorten the pump’s service life. The consequences range from irregular dosing and error codes in the engine control unit to a noticeable reduction in performance or—in extreme cases—complete immobilization of the vehicle, since modern emissions standards cannot be met without a functioning SCR system.
Support
Feeding Module, Urea Injection
| at Reference Number / Item Number | at22202 |
| OE Reference Numbers | A0024705794, A0024705494, A561198969 |
| Quality | AM |
| Vehicle Link | VW, MERCEDES-BENZ, SEAT, PORSCHE: Sprinter, Crafter, Sharan, Touareg, ALHAMBRA, CC, Passat CC, W212, W166, CAYENNE, W164, W221, W251, X166 |
Feeding Module, Urea Injection
| at Reference Number / Item Number | at22203 |
| OE Reference Numbers | BC3Z-5J229-A, BC3Z 5K227-K, BC3Z-5L229-L |
| Quality | AM |
| Vehicle Link | FORD: Transit 3,2 F250, F350, F450, F550 |
Feeding Module, Urea Injection
| at Reference Number / Item Number | at24401 |
| OE Reference Numbers | 4G0131969J, 4G0131969H |
| Quality | AM |
| Vehicle Link | AUDI: A7 |
Additional
