There's not much more alarming than cruising down the road and seeing an ominous car warning light on your dash. With so many warning lights, it can be confusing to know what each one means and which are the most serious.  In this comprehensive guide, we'll cover the key car warning lights and their level of severity. From red-light warnings to orange-light alerts, you'll learn whether you need to pull over immediately and get a tow or if you just need a little gas. 

Car Warning Light Colours

Have you ever noticed that different warning lights have different colours? Well, there are five colours to keep an eye out for: red, yellow, orange, green, and blue. There's no need to worry about green and blue lights as these simply indicate that you're using one of your vehicle’s systems (i.e, cruise control or lane-keeping assist). 

However, a red, orange, or yellow warning light is worthy of your concern. Their colour indicates a need for immediate attention. A red light tells you there’s a critical issue you must address immediately, like overheating or low oil pressure. A yellow or orange light is a softer warning about an issue you must address at your earliest convenience. This doesn't mean it's any less important than a red-light warning, but it does mean there's no need to pull off a four-lane highway immediately and call a tow truck. 

Red Car Warning Lights

Let's start with the most serious of the car warning lights, the red ones. Here's a rundown of some common red car warning lights and what they mean. 

Oil pressure car warning light

Oil Pressure Light 

This light looks like an old-fashioned oil can or a genie bottle and typically has a drip coming from one end of it. If this car warning light illuminates, it means there’s inadequate oil pressure in your engine, which can result from a failing oil pump or not having enough oil. 

Driving without the proper oil level or pressure can cause severe engine damage. If you see this light and can’t quickly make it to a gas station or repair garage, immediately pull over and have your vehicle towed to the nearest repair shop. 

Car warning lights: Coolant temperature

Coolant Temperature Light

This light looks like a thermometer dipping into water, and it means the coolant's temperature is above the manufacturer's specifications (aka overheating). This can be caused by a failing thermostat, damaged water pump, low coolant level, and other failures. If you see this light, immediately pull over and have your vehicle towed to a repair shop.

Overheating can cause severe internal engine damage, so don't try to limp the car home. 

Battery car warning light

Battery Light

The battery light is a little deceptive as its name implies it's all about the battery. In fact, this is more of a charging system warning, as it indicates a problem in the entire charging system, including the alternator, wiring, or battery.

If this light turns on, the failure likely won't damage your vehicle, but it could leave you stranded if the system fails completely. Take your car to the nearest auto repair shop to have the charging system checked.

Car warning lights: Transmission temperature

Transmission Temperature Light

Not every vehicle with an automatic transmission has this light, but some have a red light that shows an exclamation point inside a gear or displays the words "AT Oil Temp." This is the transmission temperature light, which indicates your transmission is overheating. 

This typically happens when your transmission is low on fluid, suffering a mechanical failure, or is under too much stress from towing excessive weight or aggressive driving. If this light illuminates, immediately pull over and address the situation. If towing is causing the issue, you'll want to lighten the load. 

If the light illuminates for any other reason, have the vehicle towed to a repair shop to diagnose the issue before you cause any additional damage. 

Brake warning light

Brake Warning Light

The brake warning light is a red circle with a red exclamation point in the center. In some vehicles a "P" is in place of the exclamation point. 

The brake light indicates a serious issue in the braking system, including low brake fluid level, low brake pad levels, a stuck handbrake or parking brake, or more. Because the failure is serious, it's best to stop and call a tow truck to take your vehicle to the nearest repair facility for a brake system diagnostic. 

Airbag warning light

Airbag Warning Light

The red airbag warning usually looks like a person sitting in a seat with a large ball near their lap — that ball is supposed to be the airbag. However, some vehicles skip the artwork and just display "SRS” or "Airbag" in red on the dash. 

This car warning light signifies a failure in the supplemental restraint system (SRS), including failed seatbelt pretensioners, faulty airbag sensors, and more. Because these are safety items, you should have the vehicle towed to the nearest repair facility to have the airbag system checked and repaired. 

Seatbelt car warning light

Seatbelt Warning Light

This car warning light looks like a person sitting in a seat with their seatbelt on. It usually only comes on when the seat's pressure sensor detects a person in the seat without their seatbelt on.

If the light remains on when everyone is buckled up, there could be a malfunction in the seatbelt buckle sensor. If there's no one else in the vehicle with you, it could be a faulty seat pressure sensor. You may have something too heavy in the seat that's triggering the pressure sensor, like a water bottle or a book. 

If everyone is buckled up and there's nothing on the seat triggering the sensor, take the vehicle to a repair facility to check the seatbelt system. 

Security warning light

Security Warning Light

This light can vary between cars, but it's usually a padlock or a key overlaying a car. This light will oftentimes flash when the vehicle is locked to deter thieves. If it's on while driving or when you start the vehicle, it may indicate a fault in the security system or keyfob. 

Immediately take the vehicle to a repair facility to have the security system diagnosed. In some cases, a fault in this system will prevent the vehicle from starting, so you may have to tow it in. 

Power steering car warning lights

Power Steering Warning Light

This light can sometimes be yellow or orange, but it's typically red. It looks like a steering wheel and often has an exclamation point next to it. When this light turns on, it means there’s a problem with the power steering system. 

In newer vehicles with electric power steering, this light means it's time to call a tow truck and have the car taken to the shop.

If you have a hydraulic power steering system, check if the fluid is low. If it’s low, refill it and see if the light goes out. Because the power steering system is sealed and doesn't consume oil, low fluid generally means there's a leak somewhere. Take the vehicle to a nearby repair shop to have the power steering system checked for leaks and other issues.

Yellow or Orange Car Warning Lights

While a yellow or orange car warning light generally isn't as urgent as a red one, it's still your vehicle trying to communicate an important issue to you. Here's a rundown of the main yellow or orange car warning lights and what they mean. 

Check engine light

Check Engine Light

Perhaps the most infamous warning light because of its ambiguity, the check engine light is also sometimes called the malfunction indicator light (MIL). 

While the light itself will vary between cars, it's usually a picture of an engine, but it may also be text that reads "Check Engine" or "Service Engine Soon." The ambiguity comes into play when you find out this may not be related to the engine at all

Your check engine light is a general catch-all signal for a multitude of engine, emissions control, and other powertrain failures. It can range from something as simple as a loose gas cap (emissions control) to a serious problem, like an engine knock or failing transmission shift solenoid. 

If your check engine light pops up, stop the vehicle in a safe area and first check the gas cap. All too many times, drivers overreact to this light and tow their car to the shop only to learn they left the gas cap off or didn't tighten it. If the gas cap is off or loose, tighten it until you hear a click, then start the vehicle to see if the light is off. 

If the light is still on, take the vehicle to a nearby repair shop for a full diagnostic. 

Keep in mind that it's normal for the check engine light to flash when you first start the vehicle. It's only an issue if the light stays on after starting the car.

Pro Tip: Many parts stores sell scanners that allow you to pull the code that triggered the check engine light. However, these codes only tell you the system that failed and generally require additional professional diagnostics to find the root of the issue.

Oil change warning light

Oil Change Warning Light

Today's cars will tell you when they're due for an oil change via the oil change light. The exact light may vary between vehicles, but it'll usually read something like "Change Engine Oil Soon" or "Maintenance Required." In some cases, it's simply a message and not a yellow or orange light. 

This light turns on as you near the vehicle's recommended oil change interval, whether that's 5,000 km, 10,000 km, or more. At your earliest convenience, take your vehicle to an oil change facility or do the oil change yourself, then reset the oil change light. You can find the oil change light reset procedure in your owner's manual.

Pro Tip: Every Clutch vehicle gets an oil change before it goes on sale, ensuring you won't have to deal with this warning light for a while.

Tire pressure light

Tire Pressure Warning Light

Modern tire pressure monitoring systems (TPMS) eliminate the need for periodic tire pressure checks. They'll alert you of low tire pressure with a yellow or orange light in the shape of a tire with an exclamation point inside the tire. 

If you see this light, find the nearest service station or gas station with an air pump and inflate the tires to their recommended pressure. You'll find the recommended pressure on the sticker inside your door jamb. 

If the light remains on after refilling the tires and driving for a few miles, this could indicate a problem in the TPMS. In this case, take the vehicle to a repair shop for a diagnostic.

Anti-lock brake car warning light

Anti-Lock Brake Warning Light

Your vehicle's anti-lock brake system (ABS) helps reduce braking distances by pulsating the brakes quickly. This system uses a network of sensors and controllers to pull off this feat. If any of these fail, you'll see an ABS warning light, which is a circle with "ABS" inside. 

Your vehicle will still drive fine with the ABS warning light on, but it's not safe to drive for extended periods. Immediately take your car to a repair shop to receive an ABS diagnostic. 

Traction control warning light

Traction Control Warning Light

The traction control system (TCS) uses sensors to detect wheel slip and your car's brakes to mitigate this slippage. The TCS uses a yellow or orange light that looks like a vehicle with two squiggly lines behind it. 

It's normal to see this light flicker when TCS engages. However, if the light remains on, this means there’s a fault in the TCS, including a failed wheel sensor, wiring, or control unit. 

Like the ABS light, if the TCS light remains on, the vehicle will likely still drive short distances without issue. That said, you should immediately take it to a repair facility for a diagnostic.

Stability control warning light

Stability Control Warning Light

Electronic stability control (ESC), or vehicle stability control (VSC), uses the braking system to keep the vehicle heading in its intended path. If it senses the vehicle sliding in one direction, it may engage the brakes to pull it back straight. It manages this using various wheel speed sensors and control units. 

When ESC or VSC activates, it's normal to see the "ESC" or "VSC" light illuminate momentarily. However, if the light stays on, this indicates a fault in the system. Take the vehicle to a local repair facility to have the ESC or VSC system diagnosed. 

Keep in mind that not all vehicles have an ESC or VSC light. In these cases, the TCS light will illuminate instead. 

Low fuel car warning light

Low Fuel Warning Light

The low fuel light is one of the more obvious ones, as it looks just like a gas pump. This light means you're low on fuel, so swing by a gas station and top up. The precise amount of fuel you have remaining when this light turns on varies by car, but it usually means you have 8 litres or less remaining.

Car warning lights: Washer fluid

Washer Fluid Warning Light

If your washer fluid is low, your car will illuminate a yellow or orange light that looks like a stream of water hitting a windshield. If you see this light, follow the instructions in your owner's manual to refill the windshield washer fluid. Just make sure to choose the right windshield washer fluid for your geographic area and climate. 

No Car Warning Lights at Clutch

When you buy a vehicle from Clutch, Canada's first fully online car-buying experience, you can rest assured you’ll see no warning lights on your delivery day. We put all our cars through a rigorous 210-point inspection before they go up for sale on our site. We ensure there are no warning lights on and the vehicle is in top condition during this process. 

We also back up all our vehicles sold online with a 90-day or 6,000-km warranty for additional peace of mind. Plus, if you don't love your new Clutch vehicle in the first 10 days, you can return it for a no-hassle refund or exchange it for another Clutch vehicle. 

We also accept trade-ins. Navigate to our online estimator and enter some basic information to get an estimated trade-in offer for your vehicle. If you like the offer, you can get a firm trade-in offer by submitting a few pictures of your vehicle and a little more information. When it's time to trade in your vehicle, we'll pick it up and handle all the paperwork.