Audi Repair Questions? Ask a Mechanic for Answers ASAP
The first stage of diagnosis will be a full Diagnostic Code Read using Audi approved Diagnostic Equipment. It is preferable to use Audi Equipment as it places any fault codes in order of diagnostic preference. Once you have these fault codes a diagnostic path can then be established.
The EPC light is in effect a warning that there is a problem with the Electronic Control System. It could be a sensor failure, wiring issues or a module issue. Without the first stage of the Full Diagnostic Code Read it will be impossible to proceed any further.