Seeing the EPC Light coming on and followed by the vehicle shaking on your Audi can be a terrifying experience.
You may not know what it means, but you know it’s not good. In this article, I will talk about the common causes for the EPC Light to come on and how you can fix it.
Understanding the Audi EPC Light: A Brief Overview
|EPC Light on Audi||Indicates a problem with the powertrain control module, similar to a check engine light.|
|Cause of Shaking||Engine misfiring, leading to limp mode, causing rough driving.|
|Common Causes||Bad/failing throttle body, bad ignition coil, clogged/faulty injectors, bad spark plugs.|
|Diagnosis and Fix||Use an OBD scanner for fault codes; replace faulty parts or seek professional help.|
The EPC light means “Electronic Power Control”, and is more similar to a check engine light but focuses on the throttle system of your car.
This light comes on when there is a problem with your Audi’s powertrain control module (PCM).
The shaking is caused by your engine misfiring causing your Audi to go into limp mode which makes the vehicle make shaky and rough when driving.
What Causes Your Audi to shake and the EPC light to Come on?
Now, that I have briefly explained what the EPC light means and what it does, we need to talk about the common causes for this light to come on.
This is where things get interesting because there are a variety of different things that could be causing your Audi to shake and have the EPC light come on.
But from my personal experience as a mechanic, here are a few of the most common causes arranged in order of their prevalence.
1. Bad/Failing Throttle Body
The throttle body is a critical component of your vehicle’s engine.
Without it, you would not be able to control the amount of air that enters your engine, which would make it impossible for your car to run properly or even start.
Because of this, if there is an issue with your throttle body such as a faulty sensor or a bad connection then this will immediately cause the EPC light to come on as well as your Audi to shake while driving.
2. Bad Ignition Coil
The ignition coil is a small device located on your engine on top of the spark plugs that produce high voltage electricity.
This electrical charge is then used to ignite the fuel and air mixture inside your engine.
If one of your coils stops working correctly, then this can cause problems such as stalling or misfires which can trigger the EPC light on the driver’s cluster to come on.
3. Clogged or Faulty injectors
Injectors are small devices that spray fuel into the combustion chamber of your engine.
If one of these becomes clogged or stops working correctly then this can cause problems like engine stalls, rough idling, and engine misfires.
Unfortunately, fuel injectors don’t last a lifetime and need to be replaced eventually.
A bad fuel injector is a third common cause of the electronic power control light coming on in an Audi.
4. Bad Spark Plugs
Spark plugs are another common cause of powertrain light problems.
If your spark plugs are old and worn out, they won’t be able to create the high-voltage spark needed to ignite the air/fuel mixture inside your engine.
Spark plugs on Audi need to be replaced every 48 000 – 64 000 KM (30 000-40 000 miles), depending on the model year of your car.
If you have neglected to change your spark plugs regularly, it’s likely that they are worn out and need replacing.
Practical Steps to Address EPC Light Issues in Your Audi
Lastly, let’s look at how to fix the EPC light on an Audi.
Since the EPC light is a generic fault warning and can be caused by several things. The first thing I recommend that you do is to get the car scanned to get the fault codes.
You can either do it yourself using any OBD scanner or take the car to a mechanic who will be able to do it for you.
Scanning your Audi will give you a clue about what is causing the EPC light and shaking. For instance, if the scanner shows throttle-related codes then you need to check the throttle body.
If you get cylinder misfire codes then ignition coils or spark plugs are the culprits, and if you get fuel-related codes then chances are it’s your injectors that are causing the problem.
Once you have the fault codes, you’ll know what needs to be fixed. If it’s something simple like a bad spark plug or vacuum leak then you can fix it yourself but if it’s something more complicated then I recommend taking the car to an Audi dealer or independent mechanic.