16 02 03 (036) Electronically Controlled Fuel Pump

16 02 03 (036)
Electronically controlled fuel pump
E46, E60, E61, E63, E64, E87, E90, E91





Introduction
The electric fuel pump in the "Fuel pump electronic control" system is activated as and when required. The DME or DDE control unit calculates the amount of fuel required at the given point in time. The EKP control unit controls the electric fuel pump on the basis of mappings so that the electric fuel pump delivers the exact amount of fuel required.

In conventional systems, the electric fuel pump is operated continuously at maximum speed using the highest on-board supply voltage available. The maximum amount of fuel that may be required is made available regardless of the operating conditions.
The electronically controlled fuel pump system optimises the supply of fuel and reduces fuel consumption.
The electronically controlled fuel pump system is available for both petrol and diesel engines.

Note: In this case, EKP = "Electronic fuel pump control" .
The abbreviation EKP is often used to refer to the electric fuel pump itself. The electronically controlled fuel pump system described here is controlled by a control unit called the EKP control unit. The abbreviation EKP is used here to refer to the system as a whole.

Brief description of components
The electronically controlled fuel pump system comprises the following components:
On E46 vehicles:
- DME control unit
The DME control unit (digital engine electronics) calculates the amount of fuel required based on the driver's request and the operating status of the engine.
- Local CAN
The EKP control unit communicates with the DME control unit via the local CAN.
- K-bus (body bus)
Diagnosis is performed through the K-bus. In the event of a crash, the EKP control unit is deactivated by the K-bus.
In the E60, E61, E63, E64, E87, E90, E91:
- DDE control unit
The DDE control unit (digital diesel electronics) calculates the amount of fuel required based on the driver's request and the operating status of the engine.
- PT-CAN
The EKP control unit communicates with the DDE control unit via the PT-CAN (Powertrain CAN).
The E46, E60, E61, E63, E64, E87, E90 and E91 have the following in common:
- EKP control unit
The EKP control unit controls the speed of the electric fuel pump in accordance with the DME or DDE fuel volume calculation.
- Regulated fuel pump
The controlled fuel pump is a system comprising an electric fuel pump and control unit in which the fuel pump not only pumps, it also pumps more or less depending on the requirements.
The following types of fuel pump are installed:
- E46: side channel pump (2-speed fuel pump)
- E60, E61, E63, E64: roller-cell pump
- E87, E90, E91: G-rotor pump

System function
The electronically controlled fuel pump system comprises the following functions:
- Delivery of fuel according to requirements
- Cooling and lubrication of high-pressure pump (diesel engine)
- Emergency operation

Delivery of fuel according to requirements
Amount of fuel required by the engine is calculated by the DME or DDE control unit. The total volume required is transmitted as a message to the EKP control unit via the local CAN or PT-CAN. The EKP control unit converts this message into an output voltage. This output voltage is then used to control the speed of the electric fuel pump. This achieves a delivery which corresponds with the requirements.
Cooling and lubrication of high-pressure pump (diesel engine)
On diesel engines, the fuel is also used to cool and lubricate the high-pressure pump.
The lower limit of the amount of fuel to be delivered is not determined by the minimum amount of fuel required by the engine. The parameters for lubrication and cooling of the high-pressure pump are also decisive factors.

Emergency operation
In the event that communication with the DME or DDE fails or is faulty, the EKP control unit will switch to emergency operation. The electric fuel pump is fully activated.

Notes for service staff
Service staff should note the following points:
- General information:
- Diagnosis: ---
- Encoding/programming:
- Car & Key Memory: ---

Subject to change.