A new warning light on your dashboard? You don’t figure out why it doesn’t shut off… It’s typical, an automobile is complicated and there are multiple causes why a light could occur. If it turns out your glow plug light comes on while driving your Audi S5, it might reveal some problems. In this post, we will do anything we can to support you see things more clearly. First, we will discover how the preheating light on your Audi S5 works, and then the different motives it lights up when you are driving


What is the goal of my Audi S5 glow plug light?

The main role of the engine glow plug light, which is most of the time represented by a yellow coil, is to ensure that your glow plugs are working properly. In reality, it must light up when you switch on your Audi S5 to tell you that they are heating the intake air in your cylinders and must go out after a few moments when the engine is running. This preheat light is therefore not expected to stay or come on while driving with your vehicle. However, if it turns on while driving, it may reveal multiple troubles, we will try to summarize the main ones.

What to do if the glow plug light comes on while driving on my Audi S5?

A glow light that comes on while driving on your Audi S5 or at any other time other than when the engine is started is designed to inform you to a fault other than your spark plugs, we will look at this right now. No matter the reason, a switch to the diagnostic tool will allow you to accurately understand the cause for the light up of your glow light.

My Audi S5 glow light comes on and I’m going through a loss of power

The first probability is that you detect that your glow plug light comes on while driving your Audi S5 and that you also knowledge a loss of power. In such a case, some concerns can explain its presence. Here is a list of the main causes:

  • Problem of EGR valve, indeed, if you go through a loss of power, it is possible that your EGR valve is blocked, in such a case, it is obvious that your preheat light comes on while driving on Audi S5 because it is one of the issue of which it is supposed to notify you. Have the status of your valve tested
  • Problem associated with the turbo overflow valve, in this situation the ECU can no longer control the turbo intake pressure, which can bring about turbo boost and a disturbance in the performance of the turbo.
  • Problem linked to the injection, either an injector that has seized up or the injection pump that is broken by filings or other possible foreign bodies that disrupt its proper performing.
  • Finally, the last problem that could lead to a glow indicator light on your Audi S5 coupled with a loss of power, is that your fuel filter is too dirty, you should get jerks because of a bad fuel flow in the engine.

My glow plug light comes on or is flashing but no difference on the performance of my Audi S5

Finally, we’ll give you the motives for a glow plug light that comes on on your Audi S5 without you feeling any difference in power or vehicle behaviour. In most cases, this is an electronic fault:

  • Glow plug relays or fuses to be replaced, test and replace if necessary.
  • A contactor/potentiometer on one of your pedals (brake, accelerator or clutch) has failed, often a simple de-seizure will be enough to solve the problem.
  • You have a false contact somewhere in your electrical circuit, test the other options first because it is not easy to find it alone, we recommend you to go to your auto technician.
  • Faulty injection pressure sensor, ECU error
  • If you want more tutorials on the Audi S5, go to our Audi S5 category.