Did you just see your car’s engine warning light come on and wonder, why? Why is my engine light on? The engine warning light is a warning to the driver of a vehicle malfunction. It might be a minor glitch or a serious mechanical issue.
The engine warning light is an orange engine symbol on the car dashboard. It will turn on when there is a fault in the engine system. This light comes on for several different causes, like loose fuel cap issues, fuel injection problems, oxygen sensor failure, catalytic converter malfunction, mass airflow sensor failure, vacuum leak, ignition system problems, emissions control system problems, electrical or electronic malfunctions, and engine oil problems.
In this article, we’ll explain what the engine warning light is, the circumstances under which it might illuminate, and give you some tips on how to try to resolve the problem yourself.
Common Reasons the Engine Check Light Comes On
The engine warning light can appear due to malfunctions and indicate a number of problems. These can be electronic or mechanical when you trace the origin. Indeed, electronic failures are most often caused by damaged, disconnected, or dirty sensors and probes. If they malfunction or send incorrect information to the ECU (engine control unit), the ECU triggers the engine warning light because it is no longer able to ensure the proper functioning of the engine.
Mechanical problems can originate from the fuel injection system, the emissions control system, or engine fouling. These malfunctions are potentially dangerous and can trigger limp mode, which protects the engine from damage by reducing vehicle performance.
Overall, the engine warning light illuminates when the car’s onboard diagnostic system detects a fault. The most common causes are:
1. Loose Fuel Cap
A fuel cap that is not screwed on properly can cause a leak in the tank, which will trigger the orange engine warning light once the computer has detected the leak.
2. Fuel Injection Problems
This can come from the fuel injection pump or the injectors. They are no longer able to inject the correct amount of fuel for the explosion of the air and fuel mixture.
3. Oxygen Sensor Failure
A faulty oxygen sensor is a common problem that can trigger the check engine light. If your vehicle suffers a faulty oxygen sensor, it may run erratically at idle. A faulty oxygen sensor can affect engine idle, combustion intervals, and other critical functions.
4. Catalytic Converter Malfunction
If the difference in measurement between the two probes indicates that the catalyst is no longer converting pollutants correctly, the computer records a fault and turns on the engine warning light, sometimes with an error message.
5. Mass Airflow Sensor Failure
The MAF sensor regulates the air-fuel mixture. If it malfunctions, your engine may stall, run roughly, or consume excessive fuel, which can trigger the check engine light.
6. Vacuum Leak
A loose or worn vacuum hose can cause a leak, which will trigger the orange check engine light once the computer detects the leak.
7. Ignition System Problems
Faulty spark plugs or ignition coils can negatively impact engine performance and cause the check engine light to come on.
8. Emissions Control System Problems
The check engine light can also come on when combustion and emission control parameters exceed tolerance limits.
9. Electrical or Electronic Malfunctions
The illuminating engine warning light can indicate numerous problems. These can be electronic or mechanical in origin. Indeed, electronic failures are most often caused by damaged, disconnected, or dirty sensors and probes.
Is the Engine Light Serious or Minor? Interpret the risk based on the engine warning light
When an engine malfunction occurs, the engine warning light can appear in several ways: red or orange, steady or flashing. This indicates the severity of the problem and whether or not immediate shutdown is required.
Orange and steady engine warning light
An orange warning light indicates a malfunction or anomaly that should be addressed promptly, though it does not require immediate intervention. For example, when the orange engine warning light illuminates, it indicates a persistent fault, such as a problem with the emissions control system, specifically the particulate filter. If there are no unusual noises or smoke, the driver can take their vehicle to a garage for a diagnostic check. While there is no immediate emergency, the driver should have this check performed as soon as possible.
Engine warning light (orange and steady) with a drop in performance
When the engine warning light illuminates, the driver may notice a decrease in vehicle performance, such as increased fuel consumption or high emissions. This indicates a serious engine malfunction, and the computer has entered a limp mode to prevent further problems. It is therefore strongly recommended to stop and get the vehicle to the nearest garage so that the engine can be inspected by a professional.
Orange engine warning light flashing
If the engine warning light is orange and flashing, it means the catalytic converter is damaged or overheating. The driver must immediately switch off the engine. Any further ride could cause severe damage or even a fire.
The engine warning light illuminated red and steady.
If your car dashboard is showing the engine warning light illuminated in red, this indicates a serious problem. The driver must stop as soon as possible. A lightning bolt or exclamation mark emphasizes the danger of continuing to drive.
Can I Drive With the Engine Light On?
The engine warning light alerts the driver to a malfunction that could have serious consequences. It is therefore strongly recommended to stop immediately and have the vehicle towed to avoid damaging the engine.
However, it’s not always possible to call a tow truck. Depending on the colour of the warning light, the driver may have to drive a few kilometres to the nearest garage. That’s why it’s essential to understand the meaning of the engine warning light.
Check Engine Light on, but Car Runs Fine
We’ve all experienced that engine warning light coming on at least once, even though the car is running perfectly fine. No unusual noises, no jerking, no loss of power. In short, nothing points to a serious problem. Yet, that little orange symbol keeps taunting you every time you start the car.
Sometimes it’s just a faulty sensor, a minor anomaly, or even a simple, temporary glitch in the electronic system. Modern cars are extremely sensitive. A loose connection, a small fuel issue, or a bad wiring problem is enough to trigger this warning light, without it really affecting the driving experience.
But be careful; that’s not a reason to systematically ignore it. This warning light can also signal an emerging problem, not yet visible, but which could worsen if left unattended. You should always take this signal seriously, without panicking, but remaining vigilant.
Checklist to perform when the engine warning light is on, but everything seems normal
A quick overview of simple checks you can do yourself before heading to the mechanic. No need to be a mechanic.
Check the fuel tank cap: make sure it is properly closed and that there are no fuel leaks around it.
Visually inspect the hoses: check if an air, fuel or vacuum hose is disconnected, split, or pinched.
Check the maintenance log: if you have just filled up the tank or changed the oil, check if everything has been reassembled correctly.
Test the battery: a weak battery or oxidized terminals can disrupt the electronics and trigger the warning light.
Observe the car’s behaviour: if you see that it starts normally, idles properly, and doesn’t consume more fuel, that’s already reassuring.
Connect an OBD reader (if you have one handy): this often allows you to read the fault code that caused the warning light, even if the car is running well.
These checks take five minutes and can sometimes be enough to fix the problem or at least identify it. And frankly, it saves you unnecessary stress.
What Should I Do When the Engine Light Comes On?
If the engine warning light remains on or flashes on your vehicle’s dashboard, you should turn off your car’s ignition as soon as possible. Then, try restarting the engine to check if the warning light still appears, as this can sometimes be an electrical issue rather than a mechanical problem.
In all cases, it will be necessary to take your car to the nearest garage so that a professional can carry out a car diagnosis.
Using a diagnostic tool, they can detect faults and malfunctions in the engine system in just a few minutes. They will then carry out the necessary repairs to ensure the safety and reliability of your vehicle.
Frequently Asked Questions (FAQs)
