Component Description For Fuel Pump Control Unit - GF47.40-S-2001S
Engine 651 in model 906
Shown on model 639, seat base at front right
Shown on model 906, seat base at front right
Location
The FSCU (N118/5) (in model 906) is located in the seat base of the left front seat.
Task
The FSCU (N118/5) (in model 906) regulates the fuel pump with fuel level sensor (M3/5) (in model 906 up to facelift 2013) or the fuel pump with fill level sensor (M3/5) (in model 906 as of facelift 2013).
Direct input signals
The following signals are read in by the FSCU (N118/5) (in model 906) over direct lines:
- Terminal 15
- Circuit 30
- Circuit 31
- "Fuel pump ON" (ground connection)
- Fuel pressure signal from fuel pressure sensor (B4/7) (in model 906 up to facelift 2013) or fuel low-pressure sensor (B4/7) (in model 906 as of facelift 2013)
Direct output signals
The FSCU (N118/5) (in model 906) evaluates the read in signals and actuates the following components over direct lines:
- Fuel pump with fuel level sensor (M3/5) (in model 906 up to facelift 2013) or fuel pump with fill level sensor (M3/5) (in model 906 as of facelift 2013) (12 V) (pulse width modulated signal)
- Fuel pressure sensor (B4/7) (in model 906 up to facelift 2013) or fuel low-pressure sensor (B4/7) (in model 906 as of facelift 2013) (5 V)
Body
The FSCU (N118/5) (in model 906) consists of a plastic housing with 2 plug couplings and measurement and control electronics inside.
Function
The function description is subdivided into the following points:
- Regulation of the fuel pump with fuel level sensor (M3/5) (in model 906 up to facelift 2013) or fuel pump with fill level sensor (M3/5) (in model 906 as of facelift 2013)
- Limp-home mode
- Diagnosis
- Drain fuel tank
Regulation of the fuel pump with fuel level sensor (M3/3) (in model 639) or fuel pump with fuel level sensor (M3/5) (in model 906 up to facelift 2013) or fuel pump with fill level sensor (M3/5) (in model 906 as of facelift 2013)
Switching of the fuel pump with fuel level sensor (N118/5) (in model 906 up to facelift 2013) or fuel pump with fill level sensor (M3/5) (in model 906 as of facelift 2013) occurs if the signal "fuel pump ON" from the FSCU (M3/5) (in model 906) is received.
The FSCU (N118/5) (in model 906) evaluates the current fuel pressure, compares it with the fuel specified pressure and appropriately actuates the fuel pump with fill level sensor (M3/5) (in model 906 up to facelift 2013) or the fuel pump with fuel level sensor (M3/5) (in model 906 as of facelift 2013) with a pulse width modulated signal, so that the actual value matches the specified value. In this manner, the fuel pressure is regulated to approx. 4.25 bars, depending on the fuel requirements.
The maximum feed volume for a 12 V supply voltage is 155 l/h.
Limp-home mode
If the "fuel pump ON" signal, the fuel pump with fuel level sensor (M3/5) (in model 906 up to facelift 2013) or the fuel pump with fill level sensor (M3/5) (in model 906 as of facelift 2013) is actuated for recognition of circuit 15.
Diagnosis
The FSCU (N118/5) (in model 906) leads to an own and a component checking. Recognized errors are stored and can be read out over diagnostic CAN (CAN D) with XD.
Drain fuel tank
The fuel tank can be emptied without running the engine with XD over the FSCU (N118/5) (in model 906).