Function Description Of ABS Control Module - GF42.30-P-4500-01GG
Model 463
The ABS control module is divided up functionally as follows:
- Signal conditioning
- Logic section
- Safety circuit
Signal conditioning
The following input signals are conditioned for the logic section:
- 4 speed sensors
- Stop lamp switch (S9/1)
- Acceleration sensor (four-channel system)
Logic section
The conditioned input signals are processed in the logic section and converted into output signals.
Wheel speed signals:
The conditioned speed signals are continuously compared with each other and then with specified slip thresholds (differential speeds between front and rear wheels, depending on vehicle speed).
The following values are determined by this process of comparison:
- Brake slip
- Wheel acceleration
- Front wheel driving speed
- Corner recognition
If the determined values exceed the specified slip thresholds, an ABS control mode is initiated.
Stop lamp switch signal:
When the brake is operated, a signal is transmitted to the logic section. The control module recognizes the braking process.
Safety circuit
It is the task of the safety circuit to recognize faulty signals in the control module and faults in the electrical cable system. The actuation of the solenoid valves and return pump is monitored during the control process. If a fault is detected, the system is switched off and this is displayed to the driver by the ABS MIL (Ale17) coming on. In addition on models 463.308/330/331 a fault code is stored in the control module. This fault code can be read out by the HHT.
The safety circuit also continuously monitors battery voltage. If the voltage drops below 10.5 V or the voltage exceeds 18-20V, the system is also switched off until the voltage is in the specified range again.