Delivery Unit: Notes
The delivery unit is located on the active reservoir at the top end of the function unit. Among other things, the delivery unit comprises the pump that transfers the urea-water solution from the active reservoir to the metering module. The delivery unit is also heated by a PTC element.
INDEX EXPLANATION CHART
| Index | Explanation |
|---|---|
| 1 | Pump motor and heater electrical connection |
| 2 | Reversing valve electrical connection |
| 3 | Pressure sensor electrical connection |
| 4 | Metering line fluid connection |
The heating element in the delivery unit is connected to the heater for the metering line to form one heating circuit. A power semiconductor supplies the current for this heating circuit. The power semiconductor is controlled by the DDE. The DDE can determine the current that flows across the heating elements and can therefore monitor their operation.