Fuel Pump Control Unit: Description and Operation

Fuel Pump Control Unit







The fuel pump control unit controls the voltage at the electric fuel pump in order to adapt the delivery rate of the fuel pump to the engine fuel requirement. This is performed via the control unit installed on the right-hand side of the plenum panel. The control unit is activated by a PWM signal from the DME control unit. The linear control range of the PWM signal has a pulse/duty factor of approx. 60 % - 90 %. The current consumption of the fuel pump is varied in the range between approx. 6 and 14 A by the voltage control.

Control Unit for Electric Fuel Pump EKP 1

The following control criteria are stored in the DME control unit:
- Fuel pump priming takes place for approx. 3 seconds after "ignition on"
- When the engine is started and depending on the engine-start temperature, activation takes place for approx. 5 seconds at high voltage to achieve the maximum delivery rate
- Afterwards, activation depends on the engine's fuel consumption. At idle speed, the fuel pump is activated with minimal voltage (>8 V). Depending on fuel consumption, activation is continuously increased up to the maximum delivery rate of the electric fuel pump

Control criteria in the DME control unit for controlling the control unit installed in the plenum panel:
- Fuel pump priming is carried out for approx. 3 seconds after "ignition on"
- When the engine is started, activation for approx. 5 seconds with high voltage for maximum delivery rate
- Then, depending on the fuel consumption
- at idle speed with minimal voltage (>8 V)
- from partial load state, activation increases continuously depending on fuel consumption up to the maximum delivery rate of the electric fuel pump

- The linear control range of the PWM signal has a pulse/duty factor of approx. 60 % - 90 %
- The current consumption of the pump 1 is varied in the range between approx. 6 and 14 A by voltage control