Q7 dashboard EPC warning often lights up and then the body shakes. What happened? What's the problem?

EPC = electronic power control (full name of engine electronic stability system), and 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.

For example, when we accelerate, the control unit senses that the throttle is 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. From this point of view, EPC lights are somewhat similar to the common fault warning lights or engine "check" lights in American cars.

EPC indicator lights are more common in the public. After the key door is opened, the vehicle starts self-inspection, and the EPC indicator light will light up for a few seconds and then go out. If the vehicle does not go out after starting, it means that the mechanical and electronic system of the vehicle has failed. Generally speaking, EPC lights have two possibilities. First, the throttle is dirty and needs cleaning. In another case, the brake light is not on, so it is necessary to check the brake switch and wiring.

Also, due to the oil problem, the EPC fault light will also light up.

When idling, the body shakes and the tachometer shakes up and down, which is generally caused by too dirty throttle or nozzle and too much carbon deposit. It is suggested to go to the 4s shop as soon as possible to check, clean the throttle and nozzle, and re-check with the computer.