The check engine light explained
Updated 15 Apr 2021
Picture this - You’re driving alone late one night, enjoying your favorite song on the radio.
All of a sudden, a strange orange light appears on the dashboard that kind of looks like a helicopter.
Thoughts start running through your head. What do I do? What does it mean? Should I keep dancing??
This article will give you a rundown on exactly what that light means and what to do if it suddenly appears.
That strange orange light is the Check Engine Light (CEL), or it can also be known as the Malfunction Indication Light (MIL), and is based on the shape of an engine (not a helicopter!).
This light appears when the engine control unit (ECU) detects that there is an issue with a component that it cannot rectify.
It could be coming on for any number of reasons, whether the engine is not getting enough fuel, a failed sensor, or an engine misfire.
The light will come on either in a solid state, or flashing on and off.
When the light comes on, the ECU will store what is known as a diagnostic trouble code (DTC) for the system that is causing the issue.
This will give the mechanic an idea of where to start looking in order to rectify the issue.
If the light is staying on and not flashing, this means that the ECU has detected an issue with the car that is not affecting the running of the vehicle in a major way.
This could be caused by a failed oxygen sensor in the exhaust, a sensor in the engine reading incorrectly, or simply a fuel cap that is not secured properly.
It could be a simple fix (in the case of the fuel cap, which would require tightening) or replacement of a faulty part.
You would need to have your car scanned with a diagnostic tool that plugs into the On-Board Diagnostic (OBD-II) port, located inside the cabin of your vehicle.
This can be done at any local garage, or an auto parts store, such as Supercheap Auto, at a low cost.
This is a simple process of scanning the ECU and other components for diagnostic trouble codes, which will likely lead to the system causing the issue.
This does not give the exact reason for the fault though and diagnosis of the affected system will still be required.
If the light is flashing however, this is an indication that something is seriously wrong.
The CEL flashing means that there is a chance of serious engine or catalytic converter (located in the exhaust system) damage, if the engine is operated continuously, usually caused by an emissions related problem.
This may be felt through the vehicle misfiring, or an increase in fuel consumption and reduced performance.
In this instance, it is advised to pull over to safe location as soon as possible and switch off the engine, to prevent any damage to major components.
It would be best to have your vehicle towed to your trusted mechanic, or have a mobile mechanic come out to where the vehicle is, and have a diagnostic inspection carried out, to determine the problem.
Whether it is just a small issue, or a major component that has failed, it is never a good idea to ignore the Check Engine Light, as doing so could lead to a major repair bill which could have been prevented.
Now, imagine a seamless segue here…
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Finding a passion for cars from a young age, Joel carried out work experience as a mechanic whilst at school before starting an apprenticeship after finishing year 12.
After almost 10 years on the tools and in customer service, he moved into the IT realm as a Data Analyst and In-House mechanic at AutoGuru.