Audi a4l, EPC light alarm, what's the problem?

Audi a4l, EPC light alarm, there are two situations;

(1) The throttle valve is dirty and should be cleaned.

(2) If the brake light is not on, replace the light bulb or check the brake switch and circuit.

For domestic car owners, it is generally caused by domestic oil quality and dirty environment in the car. Drive to the maintenance service station as soon as possible for maintenance, and generally clean the throttle.

Extended data

EPC=ElectronicPowerControl (full name of engine electronic stability system), many people also call it electronic throttle. The system consists of some sensors, controllers and other components.

When the sensor fails or senses an abnormal situation, the control system will take corresponding measures according to the set program.

When we accelerated, the control unit sensed that the throttle was on. At this time, due to the failure of the brake light switch itself, the control unit receives the brake signal from the brake light switch. According to the program, the control unit will reduce the fuel injection time and reduce the power output of the engine.

But at this time, the control unit also received the throttle acceleration request signal, and the computer thought that these two signals were contradictory. When the control unit cannot accurately determine the cause of the fault, it will first light the EPC lamp and give an alarm to remind the user to check.

Reference materials; Baidu Encyclopedia Audi Fault Diagnosis and Maintenance Case