Position arrangement
Pump module (19) is attached to the chassis frame at the height of the AdBlue tank.
Function
The pump module (19) draws the AdBlue from the AdBlue tank, filters and pumps it to the metering unit.
Represented in model 382.154 |
19 | Pump module |
B14.40-0022-81
B14.40-0195-09
Composition |
1 | Pressure filter | 7 | Filter bowl and the pressure accumulator | 13 | housing cover | ||
2 | AdBlue piping - forward | 8 | Coolant piping - outlet | 14 | Electrical fitting | ||
3 | AdBlue piping - return | 9 | Accumulator blowing valve | 15 | Vent membrane cover | ||
4 | Pneumatic control valve | 10 | Accumulator inflating fitting | 16 | AdBlue piping - suction | ||
5 | Compressed air connection | 11 | Engine coolant piping - intake | 17 | Drawing filter | ||
6 | Pressure accumulator | 12 | Pump case | 18 | AdBlue pump (17M01) |
The pump module comprises a housing that is synthetic material spill proof - the pump housing (12) and an aluminum block fixed in the filter housing and the pressure accumulator (7). The AdBlue pump (18) is located In the pump housing (12) - a diaphragm electric pump with 3 chambers.
In the filter and the pressure accumulator (7) housing, a pneumatic control valve (4) is located, next to the pressure filter (1) and the pressure accumulator (6). Apart from that there are pipings for the engine coolant flow and a duct to allow its flow.
Function
When the AdBlue pump (18) receives an actuation signal, it draws AdBlue from the AdBlue reservoir. AdBlue is per-filtered by the 100µm-screen suction filter (7) built in the AdBlue suction pipe.
The pump takes the AdBlue to an operating pressure of 6 bar and routes it to the filter and pressure accumulator housing (7). In order to remove minor impurities, AdBlue flows through the pressure filter (2) with 30 µm screens before being pumped towards the metering unit.
The pressure accumulator (6) is basically a storage rubber chamber, whose function is to equalize pressure fluctuations and reduce the activation frequency of AdBlue pump (18). It is comprised of a volume of approx. 0,13L. It is stored with nitrogen (N2) from the factory. When refilling, it can be inflated with air, free from oil and grease.
Vent
The pneumatic control valve (4) and the AdBlue piping - return (3) work for automatic ventilation of pump module during the initial operation. The pneumatic control valve (4) is closed when compressed air is drawn.
The AdBlue pump (18) is not actuated when it is "empty", because it turns off when the AdBlue reservoir level sensor is below a certain threshold. However, when the pump is empty, it may work for a short period if AdBlue moves inside the reservoir. However, when the pump is empty, if it works for 10 seconds more, it will be recognized by the engine control module (MR) and the ventilation will be automatically started.
AdBlue pressure reduction
To prevent the freezing of the AdBlue from damaging the pump module, after the ignition is turned off, the AdBlue pressure is reduced within the pump module and in the route through the pump module. Pressure reduction takes place through the compressed air control module ventilation. Consequently, the pneumatic control valve (4) opens and this way allows AdBlue return to the reservoir.
Heating
The engine coolant flows through the filter bowl and the pressure accumulator (7) to AdBlue heating and defrosting . The coolant supply is commanded by a valve located in the engine controlled by the engine control module (MR).