A new light on your dashboard? You don’t find out why it doesn’t shut off… It’s normal, an automobile is complex and there are multiple reasons why a light might occur. If it turns out your glow plug light comes on while driving your Mercedes Benz S Class, it may suggest some problems. In the following paragraphs, we will do everything we can to support you see things more clearly. First, we will see how the preheating light on your Mercedes Benz S Class functions, and then the different explanations it lights up when you are driving

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What is the role of my Mercedes Benz S Class glow plug light?

The main role of the engine glow plug light, which is in most cases represented by a yellow coil, is to make sure that your glow plugs are working effectively. In fact, it must light up when you switch on your Mercedes Benz S Class 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 supposed to stay or come on while driving with your vehicle. Nevertheless, if it comes on while driving, it may show different troubles, we will try to detail the most important ones.

What to do if the glow plug light comes on while driving on my Mercedes Benz S Class?

A glow light that comes on while driving on your Mercedes Benz S Class or at any other time other than when the engine is started is designed to alert you to a problem 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 interpret the cause for the light up of your glow light.

My Mercedes Benz S Class glow light comes on and I’m going through a loss of power

The first possibility is that you identify that your glow plug light comes on while driving your Mercedes Benz S Class and that you also experience a loss of power. In such a case, some concerns can describe its presence. Here is a list of the most important reasons:

  • Problem of EGR valve, in fact, if you undergo a loss of power, it is possible that your EGR valve is clogged, in such a case, it is logical that your preheat light comes on while driving on Mercedes Benz S Class because it is one of the problem of which it is supposed to warn you. Have the status of your valve examined
  • Problem related to the turbo overflow valve, in this situation the ECU can no longer manage the turbo intake pressure, which can bring about turbo boost and a disturbance in the operation of the turbo.
  • Problem relevant 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 disturb its proper performing.
  • Finally, the last trouble that could lead to a glow indicator light on your Mercedes Benz S Class coupled with a loss of power, is that your fuel filter is too dirty, you should feel 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 Mercedes Benz S Class

To finish , we’ll give you the explanations for a glow plug light that comes on on your Mercedes Benz S Class without you feeling any difference in power or vehicle behaviour. Ordinarily, this is an electronic problem:

  • Glow plug relays or fuses to be swapped out, test and change 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 trouble.
  • You have a false contact somewhere in your electrical circuit, test out the other solutions first because it is not easy to find it alone, we encourage you to go to your auto technician.
  • Faulty injection pressure sensor, ECU error

    • If you wish more guides on the Mercedes Benz S Class, go to our Mercedes Benz S Class category.