On-Board Control System (OBCS) Unit (Audi 100 C3)

On some cars, the BSK was installed by order. This system automatically controls various functions and the operation of the most important organs of the car. Malfunctions and deviations in operation are determined by light signals that light up in the instrument cluster between the round indicators. Light signals are accompanied by sound signals.

The system can generate two types of alarm signals:

• danger signals that require an immediate stop of the vehicle. In case of malfunctions or malfunctions of the vehicle's organs, the corresponding symbols light up red on the screen and are accompanied by three sound signals;
• warning signals that draw attention to organ malfunctions or dysfunctions. The corresponding symbols light up yellow and are accompanied by one sound signal.

Checking the functionality of the BSC

With the ignition on and the engine off, briefly press the button located under the coolant temperature gauge, then check that the system's indicator lights come on one by one. This checks the BSC's operability.

Application of BSC

After starting the engine, the message lights up on the screen "Bremslicht" ("Stop light"), which should go out after pressing the brake pedal.

If the organ or function being checked is in good working order, the screen will display the inscription "OK" ("Everything is in order"). If such an inscription is not displayed or not a single symbol is displayed, check the correct operation of the BSC.



If the signal "Bremslicht" does not go out, check:

• brake light bulbs;
• fuses;
• brake light switch;
• wires and their connections.

If there are any disturbances in the operation of the function or organ being tested, an audible signal is heard and the following symbols may light up:

• in case of problems with the braking system - a vertical line enclosed in parentheses and placed in a circle.

This could mean:

• low brake fluid level;
• insufficient oil level in the power steering system;
• too low operating pressure in the brake booster. In the first two cases, top up the fluid to the norm and check the tightness of the corresponding systems. In the second case, contact a service station to determine the cause of the drop in operating pressure;

• if the oil pressure deviates - an image of an oil can. In this case, stop the engine and check the oil level in the engine crankcase. If the oil level is normal, do not continue driving, do not start the engine even for idling and call a technician;
• if the temperature or coolant level deviates from the norm - a thermometer image. Stop the engine, check the coolant level. If the coolant level is normal, let the engine cool down and contact a service station;
• when the front brake pads are worn out - the symbol is a triangle in a circle. Urgently check the condition of the brake pads,
• if the low beam headlight or reversing light bulb is faulty - the bulb symbol is in a triangle. Check and, if necessary, replace the bulb, fuse or corresponding plug connector;
• if the charging current of the storage battery deviates - a symbol depicting a battery of batteries. Check the tension of the alternator drive belt, the voltage regulator and the serviceability of the battery itself;
• if the fluid level in the windshield washer reservoir deviates, the reservoir image is in a triangle. Fill the reservoir;
• at minimum fuel level in the tank - image of a gas station. There is no fuel left in the gas tank. Refuel immediately.

(Content source: the specified website «AUDImanual»)