Anamber symbol of an engine is glowing on your dashboard, but what does it mean?Every image on your dashboard has a purpose and when something lights up toindicate a potential problem, it shouldn’t be ignored. The check engine light,which signifies several possible issues including emissions, is the most common.
Thecheck engine light (CEL) illuminates after being prompted by the engine controlunit that manages the engine. If the control unit determines that something inyour engine is not functioning properly, it will send the signal to light upthe symbol on the dashboard. So, you see it blink to life, but what should youdo?
Unlike certain symbols which tell you exactly what is wrong with your vehicle,such as the coolant temperature light that alerts you of overheating, the CELcan glow for several reasons. Because of this, you should take it to a garagefor the technicians to determine the root cause and go from there.
As you won’t be immediately aware of the cause, there are several things youcan do initially to try and solve the issue.
1. Observe
Check that there are no other symbols on your dashboard indicating additionalproblems, such as low oil pressure or overheating. If this is the case, pullyour vehicle over, shut the engine off and contact a roadside service.
2. Check gas cap
Tightenor replace your gas cap as sometimes a broken or loose rubber seal can triggerthe light to come on.
3. Reduce pressure
If you think that your vehicle feels different on the road, especially if theperformance has decreased, reduce your speed and avoid transporting heavygoods.
4. Check whether the engine lightis constant or flashing
Asolid glow tells you that you should have your vehicle inspected soon, howevera blinking CEL is a greater cause for concern and indicates that your vehicleshould be inspected by a professional immediately.
What can cause the emissions light to come on?
There are several different possible triggers for an illuminated engine light. The following are some of the most frequent causes.
- Emissions system fault
Youremissions control monitors the volume of carbon monoxide that your vehicleemits while in motion. This is something that people are becoming increasinglyaware of by opting for more eco-friendlyvehicles toreduce their carbon footprint. A component of this is the oxygen sensor, whichcan sense if the engine is burning too much or not enough fuel. This cantrigger the CEL to indicate that the car is either running too rich or toolean, or that there’s an issue with the sensor itself.
- Blocked diesel particulate filter
Thisfunction measures how easily gas is able to travel through the exhaust. As thisgas moves through the system, it must pass through the particulate filter,which removes harmful particles from the exhaust. It does this by oxidising theparticles into a fine ash. The CEL may illuminate if this process fails in someway, or if the filter becomes blocked.
- Mass airflow sensor fault
Theengine control unit calculates how much fuel to add to the combustion chambersbased on data from the mass airflow sensor. This sensor gathers informationfrom an air filter, which, if incorrectly installed or clogged, can damage thesensor. If this is the case, the CEL will appear.
- Ignition system fault
Responsiblefor burning the fuel that starts an engine is the ignition system. Faults withcomponents such as glow plugs, spark plugs and coil cylinders can all beindicated by the CEL. These kinds of faults are known as ‘misfires’ and repairoften involves getting replacements.
How to reset an emission warning light
You should take your car to a garage, who will give it afull examination, solve the problem and turn off the light for you. If thelight doesn’t turn off automatically, then you can try the following methods.It’s important that you get the problem fixed rather than simply resetting yourlight without looking into any potential causes.
The easiest method to reset the check engine light is todrive your car as you normally would and let the light turn off naturally byitself. If it hasn’t turned off after three days, turn the car on and off threetimes consecutively.
If the CEL still isn’t turning off, it’s time todisconnect and reconnect the battery. While the engine is not running, use awrench to disconnect the positive power cable and leave it for 20 minutes. Turnthe key in the ignition to the ‘ON’ position. Reconnect the positive batterycable and turn the key in the ignition, wait a few minutes and the CEL shouldbe gone.
If neither of these work, it’s best to take your vehicleinto a garage so that a professional can reset your light. They will also runproper diagnostics and find the exact cause behind it illuminating in the firstplace and determine if there are any issues with your car.
Can you drive with the exhaust emissions light on?
It is safe to drive with an amber check engine light glowing on your dashboard, especially if you cannot detect any problems with the smooth operation of the car. However, it’s always best to find the reason why it came on in the first place, even if that means taking it to be looked at by a professional. If the CEL glows up in red, that is greater cause for concern and you should pull over where appropriate and arrange for immediate inspection.
