Electronic power train control (EPC) is a controlling element of a Volkswagen's traction system. This system keeps a VW from skidding and having wheels spin on slick surfaces. It also aids in smoother starting and shifting between gears.
VW Warning Light System
Modern VW models have the ability to warn users about a broad array of problems by sending codes to the dashboard. These codes are general in that they indicate the system of the vehicle experiencing difficulties, but not the specific problem within the system.
EPC Warning Light
An EPC warning light in a VW indicates a problem in the power train control system. This can be one of 17 faults, including lack of messaging between the power train and many systems, such as the fuel injector or air conditioning unit. It can also indicate performance control problems, defects and malfunctions of the EPC.
Finding a Specific Error Code
To find which of the 17 problems a VW is experiencing when it displays the EPC code, a sensor such as the OBD II Scanner needs to be purchased, or the VW must be taken to a service that provides error code scanning using such a device. These devices are plugged into the vehicle to read manufacturer-specific codes for the VW.