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Home >> BMW >> 2019 >> X3 M40i >> Repair and Diagnosis >> External Pages >> Different car >> Section 575 (Functional Descriptions - F25 - Cooling System, Engine Performance) >> Engine Performance - Functional Description >> Fuel presupply control >> DDE control unit with fuel presupply pressure control function

DDE control unit with fuel presupply pressure control function

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The fuel presupply pressure control function is integrated in the DDE control unit. The DDE determines the current actual pressure in the fuel presupply pressure system via the fuel pressure and temperature sensor. The DDE calculates from several input variables the control variable which is required to adjust the fuel presupply pressure. The fuel presupply pressure is adjusted to a pressure of 4.8 - 5.0 bar (absolute).

The input variables relevant to determining the control variable are:

The control variable is sent in the form of a CAN message to the fuel pump control module (EKPS). The control variable is sent in the unit l/h. The value range is 0-254 l/h.

Fig 1: Overview Of Fuel Supply Pressure Control
G09908958Courtesy of BMW OF NORTH AMERICA, INC.
Item Explanation
1 DDE control unit
2 EKPS control unit
3 Fuel tank
4 Fuel delivery line
5 Fuel filter with fuel heating unit
6 Fuel pressure and temperature sensor
7 High pressure pump
8 Input signal, engine speed
9 Input signal, fuel injection rate
10 Fuel presupply pressure control
11 Activation, fuel heating unit
12 Signal, fuel temperature
13 Signal, fuel presupply pressure