(Component Description For Fuel Pump Control Unit - GF47.40-P-2001OLG)
ENGINE 642.826, 651.960 in MODEL 166
up to model year 2016
Shows model 166.0
Location
The fuel system control unit is located on the right below the rear seat.
Task
The fuel system control unit regulates the fuel pump (M3) in accordance with requirements and transmits information about the current fuel pressure to the CDI control unit (N3/9).
The fuel system control unit is supplied by the "Continental Automotive GmbH" company and bears the internal designation FSCM-light (F uel S ystem C ontrol M odule-light).
Input and output signals
The following input signals are evaluated by the FSCU and the respective output signal is issued:
- Direct input signals
- Direct output signals
- CAN input signals
- CAN output signals
Direct input signals
- Terminal 15
- Terminal 30
- Circuit 31
- Ground signal "Fuel pump ON"
- Fuel pressure sensor sensor signal (B4/7)
Direct output signals
- Fuel pressure sensor power supply (5 V)
- Fuel pressure sensor ground connection
- Fuel pump (12 V) (pulse width modulated signal)
- Fuel pump (pulse width modulated signal)
CAN input signals
- Fuel pump ON
- Fuel specified pressure
CAN output signals
- Fuel pressure
- Diagnostic data
Body
The fuel system control unit consists of a fuel housing with two plug connections and internal measuring and control electronics.
Function
The function description is subdivided into the following points:
- Controlling the fuel pump
- Fuel system control unit limp-home mode
- Diagnosis
- Tank drainage service
Controlling the fuel pump
Switching on of the fuel pump takes place if a "fuel pump ON" signal is received by the FSCU. This signal is sent redundantly from the CDI control unit as a CAN signal via the drive train CAN (CAN C) and as a ground signal.
The fuel system control unit also receives the CAN signal "fuel requirements" from the CDI control unit.
The fuel system control unit detects the current fuel pressure by means of a voltage signal from the fuel pressure sensor and transmits this information via the drive train CAN to the CDI control unit.
The fuel system control unit evaluates the current fuel pressure, compares it with the specified fuel pressure and actuates the fuel pump accordingly by means of a pulse width modulated signal in such a way that the actual value corresponds to the specified value.
Depending on the fuel requirements, fuel pressure is varied from about 4.0 bar.
Fuel system control unit limp-home mode
- If the signal "fuel requirements" is missing a substitute value is created and the fuel pump is appropriately actuated by the fuel system control unit.
- If the "fuel requirements" signal and the signal from the fuel pressure sensor are missing, the fuel pump is actuated by means of an established permanent PWM signal (maximum delivery).
- Various limp-home functions ensure that the fuel supply is also ensured for a failure of the internal control system (e.g. failure of the processor).
Diagnosis
The FSCU performs am own and component check.
Recognized errors are stored by the fuel system control unit and sent to Xentry Diagnostics via the diagnostic CAN to the CDI control unit via the drive train CAN.
Tank drainage service
The fuel tank can be emptied over the FSCU without the engine running.
To do this, the container draining function is selected using Xentry Diagnostics, and the following parameters are entered:
- Parameter 01 for "fuel pump ON"
- Time "0-99999" s
- Duty cycle of the PWM signal to 100%
During draining, Xentry Diagnostics must remain connected and the ignition must remain switched on.
Variants
The vehicle and engine variants are already stored in the FSCU. After replacement of the FSCU a variant coding must be carried out.
| Wiring diagram for FSCU | N118 | PE47.40-P-2101-97NAB |