Can You Drive a Car with the Check Engine Light On?

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You’re driving, when suddenly the dreadful yellow-orange Check Engine Light comes on!

What should you do? Click to learn about GOFAR

Keep driving or pull over?

It can be confusing. Follow these steps:

Step 1: Check engine light is flashing.
The check engine light is typically a yellow or red engine shaped icon situated in the middle of your vehicle dashboard, behind the driving wheel. If it’s flashing for more than 6 seconds, that is potentially an emergency situation.

Step 2: Stop driving. Safely pull over.
Slow down, pull over to the kerb and stop. This will give you time to check on the problem. Otherwise, you risk damaging your car.

Step 3: Diagnose the issue with a diagnostic app
If the check engine light is on and steady (not flashing), you can keep driving as long as the car isn’t performing strangely. How is it handling? Driving straight or wonky? Do you hear any strange sounds from the engine bay? Can you see any steam or smoke coming from the car? Use your hands, eyes, ears and nose to assess whether there is something unusual happening with your car.

Step 4: Fix the problem. Decide whether to install an OBD2 diagnostics device or visit a mechanic.
An OBD2 scanner is able to diagnose the car warning light problem and alert you to future issues. A diagnostics tool, such as GOFAR (view full feature list), can be used by anyone, not just a mechanic. GOFAR comes pre-loaded with 20,000+ error codes and tells you, in non-technical terms, what the issue is with your vehicle.

Get GOFAR Now! – It’s like having a mechanic in your pocket.

Why is your Check Engine Light Flashing?

Let’s dig a little deeper into why your dashboard warning lights are on …

Check Engine Light on Car Dashboard
View all Car Warning Light Symbols and Indicators

Every car has an assortment of car warning lights on the dashboard and they all have a different meaning. The check engine light is easily identified. It looks like an engine and typically includes words such as “check.” Usually yellow or red.

It’s main function is to let you, as the driver, know that one of the car’s sensors is not functioning correctly. The check engine light will either be in a solid unblinking state or flashing.

Whenever you start your car you’ll notice that the check engine light glows temporarily – usually for around six seconds.

Every error light has a corresponding error code. These are diagnosed, and explained, by an OBD2 Scanner.

The cost for an OBD2 scanner ranges from a few dollars to hundreds. You can buy a quality scanner online.

Don’t Trust Your Mechanic? Get help here

What Could Cause Your Check Engine Light to Come On?

The Check Engine Light, also called the Malfunction Indicator Light (MIL) is a warning light (sometimes called a tell-tale) that indicates a malfunction with your vehicle (as detected by your car’s computerised engine-management system).

When something goes wrong in this complex collection of components and sensors, it triggers this light.

It’s usually displayed on your dashboard as a pictogram or symbol of an engine, or sometimes simply CHECK ENGINE, or CHECK ENGINE SOON.

Did You Know? – When you start the car, the check engine light always comes on. But if no problems are detected, it should turn off within 6 seconds.

When the check engine light does stay on… Don’t. Panic.

Check whether your car is behaving differently. Is it bucking, surging, or making unusual sounds?

If you observe nothing strangely unusual, you could keep driving to your nearest car dealership or repair centre.

The warning light usually has 2 stages:

  1. Steady (indicating a minor fault); and
  2. Flashing (indicating a severe fault).

When the light is on, the engine control unit actually stores a fault code related to the malfunction, which can be read and interpreted by an On-Board-Diagnostics or OBD2 scan tool.

All cars built in the US after 1996, in Australia after 2006 (petrol) and 2007 (diesel), in Canada after 1998, and in the UK and Europe after 2001 (petrol) and 2004 (diesel), are OBD2-compliant.

GOFAR Alerts
GOFAR diagnoses your car faults. Try it now.

Your mechanic will then read the generated fault codes on your car’s computer using a scan tool and recommend the necessary repairs or parts required to rectify the problem/s… and bill you for the cost, of course.

The thing is, this warning light can indicate almost anything from a loose fuel cap to a (far more serious) engine knock.

OR… You could stay one step ahead of your mechanic and use GOFAR to self-diagnose your car’s fault codes and immediately understand the severity of the fault.

GOFAR explains more than 300 common error codes in plain, simple English.

No confusing acronyms, no technical jargon, no obscure references that only automotive engineers can decipher. Just an easy-to-understand explanation of what your car’s computer is trying to tell you is wrong.

Most Common Causes for the Check Engine Light to Come on

Faulty Oxygen Sensor

The Oxygen Sensor measures the amount of oxygen in your exhaust system. It then communicates this information to your car’s computer so that it can adjust the engine’s air and fuel mixture.

When your oxygen sensor is faulty, your car will use up more fuel and produce more emissions.

A faulty oxygen sensor is not an alarming problem, but get your mechanic fix it as soon as is convenient.

Faulty Gas Cap / Fuel Cap

A cracked, faulty or loose gas cap / fuel cap can cause your engine light to come on – mainly because the fuel system has a vapour leak.

In other cases, it could be a more serious leak in the upper portion of the fuel system.

Tighten or replace the gas cap, then keep driving. After driving for a while, the check engine light should go off. if it doesn’t, it may be time to ask your mechanic to check it out.

Failed Catalytic Converter

A Catalytic Converter controls emissions in your car’s exhaust system. It converts carbon monoxide and other harmful gases into less harmful byproducts.

If your catalytic converter is failing, you’ll spend more money on fuel and your car’s performance will be impacted.

A catalytic converter is generally an expensive car part, costing around $500-$1,000 each. And some cars have four of them!

Therefore, if it is the cause for your car check engine light to come on, get a mechanic to check it out. Do not attempt to drive any further as you could cause costly damage to your car.

GOFAR screenshots car health
Fix Your Car Warning Light. GOFAR will diagnose the problem.

Faulty Mass Airflow (MAF) Sensor

The Mass Airflow Sensor or MAF Sensor helps your car’s computer determine the amount of fuel to be added based on the amount of air coming into the motor.

A common cause of MAF sensor failures is a dirty air filter or one that’s not properly installed.

A MAF sensor failure is not an emergency. However, until you have it replaced, you will experience a decrease in fuel economy, poor car performance, and rough engine idle.

Since your car’s air intake system is quite technical, get a professional mechanic to fix a faulty mass air flow sensor.

Faulty Spark Plugs

Do you replace your vehicle’s spark plugs according to your car’s maintenance schedule in your manual? If you’re not sure, check with your service provider.

Faulty Spark Plug
Faulty Spark Plug

If not, bad or failing spark plugs could be the reason your check engine light is on. Have them replaced as soon as possible by a certified mechanic.

Faulty Ignition Coil

The Ignition Coil is part of your vehicle’s ignition system.

It functions as an induction coil by converting a vehicle’s voltage to the required volts so that it triggers the spark plug to ignite the engine’s air-fuel mixture.

Faulty Ignition Coil
Faulty Ignition Coil

When the ignition coil burns or shorts, the check engine light will come on.

If the ignition coil is faulty, it is worth getting your entire vehicle’s ignition system checked by a mechanic or auto-electrician.

Faulty Charging System

Unless you want to find yourself in a situation where you need to jump start your car, ensure you have your battery checked regularly and that the charging system is working smoothly.

If your car won’t start, the problem could be a fault with the alternator or some other part of the vehicle’s electrical charging system.

How Urgent is the Check Engine Light?

There are several reasons why a Check Engine Light may come on. Whether it’s something as minor as a loose gas cap or something more serious like a failed catalytic converter, it should be checked out and fixed.

Let’s look at the urgency levels in more detail…

Flashing Check Engine Light

The rule of thumb is that if the check engine light is flashing, you can’t keep driving the car. It’s an emergency. Often it indicates an engine misfire.

If you keep driving, you will likely cause irreversible damage, mostly to the (expensive) catalytic converter.

Don’t risk that expense – have your car towed to a certified mechanic for repair.

Steady Check Engine Light

It’s okay to drive the car if the check engine light is steady. But only if the vehicle’s essential systems such as brakes and lights are operational.

Keep a close eye on your car’s dashboard warning lights, including the coolant temperature and oil pressure.

You can also use an OBD2 Reader (also called a OBDII Scanner) such as GOFAR to erase the fault codes and reset the check engine light.

Warning: Do not ignore the issue if it is serious. Take your car as soon as possible to a certified professional for proper diagnosis and repair.

Can the Engine Light Go Off On Its Own?

Until the cause of the Check Engine Light coming on is addressed, it will remain on.

Once the error codes from your vehicle’s computer are addressed and cleared from its memory, the Check Engine Light will go off, as long as there are no more failures that would turn the light back on and trigger another warning code.

How do You Diagnose Car Check Engine Light Warnings?

If you don’t know the exact reason why your Check Engine Light is on, then it can be very difficult to immediately determine if it’s safe enough for you to drive or not.

The good news is that an OBD Code Reader like GOFAR is a cheap and easy way to self-diagnose your car’s common errors.

Can you drive if the check engine light is on?
Self-diagnose car problems with GOFAR

GOFAR constantly monitors your car’s health and instantly alerts you to any problems it detects.

Right on your smartphone.

Explained in plain English – what the car warning light means, its severity and what you should do about it… before it becomes expensive.

Protecting your precious asset 24-7-365, whether it cost you $10,000 or $100,000, has never been more cost-effective.

Car Diagnostics In 2019 And Beyond

As we move beyond 2019 and further into the 2020s, cars are becoming increasingly smarter as connectivity and the Internet of Things change the way the automotive industry adapts to these innovations.

Vehicle maintenance is becoming increasingly defined by concepts such as remote diagnostics and even predictive diagnostics (or prognostics, as opposed to traditional diagnostics) – made possible by emerging tech like artificial intelligence and deep learning neural networks.

Industry research forecasts that the global automotive remote diagnostics market will grow at a CAGR (compound annual growth rate) of almost 17% from 2017 to 2021.

Having access to your car’s ‘brain’ (called an ECU or ECM) through affordable tools such as GOFAR is an easy way to take advantage of all this innovation without having to spend thousands on expensive equipment or understand the increasing complexity of your vehicles.

In conclusion

Don’t let the Check Engine Light make you panic and ruin your drive to work.

Just remember:

  • When the check engine light is flashing, it’s an emergency and you need to safely pull over and then tow your car to the mechanic.
  • Learn about car warning lights in our resource centre.
  • When the light is solid/steady, you can keep driving but use a leave-in OBD2 scanner like GOFAR to identify the issue.

Related: Car Warning Lights Resource Centre

Danny Adams sitting in a chair with a laptop

Danny Adams

Co-founder of GOFAR and with a Computer Science background from Harvard University, and a Bachelor of Aerospace, Aeronautical & Astronautical Engineering (Honours), UNSW. I want to transform data from cars into useful services so -> drivers save time & money -> emissions fall -> Australian roads are safer. So we built an ATO-compliant logbook app called GOFAR. I write to help you understand how to use GOFAR to maximise business travel. Reach out via

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This content is provided for general information purposes only and does not constitute professional advice from GOFAR. We recommend consulting with an independent legal, taxation, or financial expert to ensure the information is applicable to your specific situation. Please note that relevant regulations and laws may evolve over time.
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