GF42.46-P-4500-03SL SBC Control Unit, Function

GF42.46-P-4500-03SL SBC control unit, function





Function
A7/3n1 The functions of the SBC control unit are divided as follows:
^ Signal conditioning
^ Function logic component
^ Safety circuit

Signal conditioning
The following input signals are processed by the function logic component for calculations or as information:
^ Brake pedal speed
- SBC pedal value sensor signal (B37/1)
- Front axle pre-pressure sensor signal (A7/3b1)
^ Computation of actuation of high-pressure charging pump (A7/3m1)
- Memory sensor signal
^ Vehicle speed
- Wheel speed sensor signals

Function logic section
The conditioned input signals are processed in the logic section and converted into output signals:
^ Rpm sensor signals:

The 4 wheel speed signals are passed on via the CAN SBC and discrete lines to the ESP, SPS [PML] and BAS control unit (N47-5).
^ Signals to the ESP, SPS [PML] and BAS control unit (N47-5):

The wheel pressure signals of all 4 wheels, the stop lamp switch signal (S9/1), the front axle pre-pressure signal, the storage pressure and pedal travel are passed on for further processing to the ESP, SPS [PML] and BAS control unit (N47-5) via the CAN SBC.
^ Pressure regulator:

The pressures computed by the ESP, SPS [PML] and BAS control unit (N47-5) are adjusted at the brake calipers of the individual wheels.
^ Basic brake function:

In the event of failure of the ESP, SPS [PML] and BAS control unit (N47-5) or in the event of missing or faulty communication between the ESP, SPS [PML] and BAS control unit (N47-5) and SBC control unit (A7/3n1) a basic brake function for the brake booster as well as a fixed installed brake force distribution is made available.

^ Brake servo assistance in the pre-run and run-on phase:

The SBC control unit (A7/3n1) takes care of the necessary brake servo assistance during the pre-run and run-on phase.

Safety circuit
The safety circuit detects faulty signals from sensors, faults in the control unit and in the electric line system. Actuation of the high pressure charging pump is monitored during the control process. The solenoid valves are monitored permanently. If a fault is detected, then the system is switched off and this is displayed to the driver by the multifunction display (A1p13) in the instrument cluster (A1). In addition, a fault code is stored in the control unit. The safety circuit also constantly monitors the battery voltage. If the voltage falls below 8.5 V or exceeds 17.4 V, the system is switched off or operates with only limited functionality until the voltage returns to its specified range.