What does it mean when the car's EPC light is on and the engine keeps shaking?
2 Answers
The reasons for the car's EPC light being on and the engine continuously shaking are: 1. The electronic throttle is dirty or has excessive carbon buildup; 2. The fuel used does not meet standards; 3. ECU malfunction; 4. Insufficient car battery power; 5. False alarm by the car. The functions of EPC are: 1. To precisely control the throttle opening, improving fuel economy; 2. Quick system response for satisfactory handling performance; 3. Integration of idle control, cruise control, and vehicle stability control, simplifying the control system structure. EPC stands for Engine Power Control system. Its working principle is: The engine control unit calculates the optimal target throttle opening based on position data feedback from the pedal sensor, then sends a signal to the throttle drive motor to rotate the throttle to the correct angle.
When I noticed the EPC light in my car was on and the engine kept shaking, my heart was in my throat. I've experienced this several times, mainly due to issues with the electronic throttle system, like a dirty throttle body or excessive carbon buildup, which obstructs airflow and causes unstable engine operation. The shaking might be caused by engine misfiring, such as worn spark plugs, faulty ignition coils, or even poor fuel pump supply. The last time my car had this problem, I tried driving a bit, but the shaking only got worse. The mechanic said it was a chain reaction triggered by a short circuit in the sensor wiring. I recommend slowing down and stopping as soon as you notice this issue—don’t risk driving further, as it could damage internal engine components. Have a professional mechanic use a diagnostic tool to read the trouble codes. Usually, cleaning the throttle body or replacing parts can fix it—it’s not expensive but ensures safety. Remember, ignoring small problems can lead to bigger troubles.
