What does the epc light mean on a audi a4?

This indicates a fault within the traction, throttle pedal or cruise control systems. Its difficult to say exactly which system or part is failing, which is why Youll likely need a complete diagnostic procedure if Your EPC light is flashing on. In an AudiA4, EPC stands for electronic power control. This is the digital system by which the car manages its resources and the engine. Apart from directly controlling and monitoring the engine, it also oversees numerous other features that require computing power. It serves as the nervous system of sorts to the cars internal network of transmission and so, controls many different parts of the vehicle. When the EPC light is on, it means that the car is experiencing some sort of malfunction within the systems controlled by the EPC.