The Dashboard Lights You Should Never Treat as “I’ll Deal With It Later”

A warning light comes on.

You glance at it, think, “I’ll check that later,” and carry on with your day.

Then later becomes next week. Next week becomes next month. Eventually, the light has been on for so long that you barely notice it anymore.

That can be a costly habit.

Not every dashboard light means you need to pull over immediately. Some are reminders, some point to minor faults, and others mean the car should not be driven any farther than necessary. The tricky part is knowing which is which.

The colour of the light matters, whether it is flashing matters, and what the car is doing at the same time matters even more.

Here are some dashboard warnings that deserve your attention.

Start With the Colour

Most vehicles use colours to give you a rough idea of how urgent a warning is.

Green and blue lights are usually there to show that a feature is operating. Headlights, high beams, cruise control and similar functions commonly use these colours.

Amber or yellow generally means the vehicle has detected a problem that needs checking. You may be able to continue driving, depending on the warning and how the vehicle feels, but it shouldn't be ignored indefinitely.

Red usually means the problem is more urgent. Red warnings can relate to oil pressure, engine temperature, braking and other important systems.

There is also a difference between a light that stays on and one that flashes.

A steady check-engine light, for example, can sometimes be driven with cautiously until the vehicle can be diagnosed. A flashing check-engine light is more concerning and can indicate an engine misfire that may cause further damage.

When a warning appears, don't just look at the symbol. Look at the whole situation.

1. Oil Pressure Warning Light

The oil pressure warning light is usually shown as an oil can.

It is often mistaken for a routine oil-change reminder, but that's not necessarily what it means.

The engine needs a steady supply of pressurized oil to lubricate its moving parts. If oil pressure drops too far, components inside the engine can begin running without enough lubrication.

That can cause serious damage.

A low oil level is one possible reason for the warning, but it isn't the only one. An oil leak, failing oil pump, blocked oil passage, excessive engine wear or a faulty pressure sensor can also be involved.

If this light comes on while you're driving, pull over somewhere safe and switch the engine off.

Check the oil level once it is safe to do so. If the oil level is normal and the warning remains, don't assume the sensor is faulty and continue driving. The problem needs to be diagnosed.

An engine can go from running normally to needing major repairs surprisingly quickly when oil pressure is too low.

2. Engine Temperature Warning

Engines generate a lot of heat, which is why the cooling system has such an important job.

The temperature warning light can appear when the engine is getting too hot. You might also notice the temperature gauge moving into the hot zone, steam coming from under the hood, a coolant smell or reduced engine performance.

There are several possible causes, including:

• Low coolant

• A coolant leak

• Faulty thermostat

• Damaged water pump

• Radiator problems

• Cooling fan failure

• Head-gasket problems

Continuing to drive an overheating vehicle can turn a cooling-system repair into an engine repair.

If the temperature is climbing, find a safe place to stop. Turn the engine off and allow it to cool.

Don't immediately remove a hot radiator or coolant-system cap. The system can be pressurized, and hot coolant can cause serious burns.

Also, don't assume that being close to home makes it safe to continue. If the engine is overheating, another five or ten kilometres can make the situation considerably worse.

3. Brake Warning Light

The red brake warning light can mean something as simple as the parking brake being engaged.

If the parking brake is released and the light stays on, however, it needs attention.

Depending on the vehicle, the warning can be related to low brake fluid or a problem with the braking system.

Pay attention to other symptoms too.

Is the brake pedal softer than usual? Does it travel farther before the brakes engage? Is the vehicle pulling to one side? Are you hearing grinding or scraping?

Those signs shouldn't be ignored.

Low brake fluid can sometimes be related to worn brake components, but it can also point to a leak. Simply adding fluid without finding out why the level dropped may only hide the problem temporarily.

Since the brakes are responsible for stopping the vehicle, this isn't an area where putting off a repair makes much sense.

4. Check Engine Light

The check-engine light is probably the warning most drivers have learned to live with.

It can be triggered by something relatively simple, such as a loose fuel cap, but it can also be connected to problems with the ignition system, fuel system, emissions equipment, oxygen sensors, catalytic converter or other engine components.

That's why guessing based on the light isn't very useful.

A diagnostic scan can retrieve trouble codes from the vehicle's computer. Those codes help narrow down the problem, although the code itself isn't always proof that one particular part needs replacing.

For example, an oxygen-sensor-related code doesn't automatically mean the sensor itself has failed. There could be another issue causing the sensor to report an abnormal reading.

A flashing check-engine light is more serious. It can indicate a severe misfire, and continued driving may damage the catalytic converter.

If the engine is shaking, running badly or losing power while the light is flashing, stop driving unless you need to move the vehicle to a safe location.

5. Battery Warning Light

The battery-shaped warning light doesn't always mean you need a new battery.

It can indicate a problem with the vehicle's charging system.

The alternator normally supplies electrical power while the engine is running and keeps the battery charged. If the alternator, drive belt, wiring or another part of the charging system fails, the vehicle may begin relying on the battery's stored electricity.

It might continue running for a while.

Then the electrical power runs out.

You may notice dim headlights, electrical accessories behaving strangely, difficulty starting or several warning lights appearing together.

If the battery warning comes on while you're driving, have the charging system checked rather than assuming the battery is the only problem.

6. ABS Warning Light

ABS stands for Anti-lock Braking System.

During hard braking, ABS can help prevent the wheels from locking completely. That can help the driver maintain steering control while braking.

If the ABS warning light comes on, the regular brakes may still work, depending on the fault, but the anti-lock system may not be available.

The vehicle can feel completely normal during everyday driving, which makes this warning easy to put off.

The problem is that ABS is most useful during situations you don't plan for a sudden stop, slippery road or unexpected obstacle.

Have the system checked, particularly if the ABS light appears together with the regular brake warning light.

7. Tire Pressure Warning Light

A tire-pressure warning isn't necessarily an emergency, but it shouldn't be ignored.

Cold weather can lower tire pressure enough to trigger the warning. A small puncture can do the same thing.

A slow leak is particularly easy to miss. The tire may look fine while gradually losing pressure every few days.

Driving with the wrong tire pressure can affect handling, braking, fuel consumption and tire wear.

Check the pressure when the tires are cold and compare it with the recommended pressure listed on the vehicle's door-jamb label or in the owner's manual.

One important detail: don't automatically use the pressure printed on the tire sidewall. That number generally refers to the tire's maximum rated pressure, not necessarily the correct pressure for your particular vehicle.

If one tire repeatedly loses pressure, have it inspected rather than simply adding air every few days.

8. Airbag Warning Light

The airbag light is another one people sometimes ignore because the car continues to drive normally.

That is missing the point of the warning.

Airbags are part of the vehicle's restraint system. Depending on the vehicle, the system can also include crash sensors, seat-belt pretensioners and other components.

A fault could prevent part of the system from operating correctly during a collision.

There may be no difference at all in how the car drives.

That's why waiting for a strange noise or change in handling isn't going to help here. If the airbag warning stays on, have the system inspected.

9. Power Steering Warning Light

Power steering makes turning the vehicle much easier, particularly at low speeds.

If the power-steering warning appears, you may notice the steering wheel becoming considerably harder to turn.

Older vehicles often use hydraulic power steering, while many newer vehicles use electric systems. The possible causes therefore vary between vehicles.

If steering suddenly becomes heavy, don't continue driving normally just because the vehicle can technically still be steered.

Find somewhere safe to stop and have the problem checked.

A steering problem can become particularly difficult to manage when parking, making tight turns or reacting to something unexpectedly on the road.

10. Transmission Warning

Not every vehicle has a specific transmission warning light, but transmission problems often come with other warnings or noticeable changes in how the vehicle drives.

Watch for:

• Delayed gear changes

• Hard or jerky shifting

• Slipping between gears

• Unusual whining or grinding

• Burning smells

• Difficulty selecting a gear

• The vehicle getting stuck in one gear

Transmission problems can start with something relatively manageable and become much more expensive if they are left alone.

For example, continuing to drive with a transmission that is slipping can create additional heat and wear.

If the vehicle suddenly starts shifting differently, don't wait for it to stop moving altogether before getting it checked.

What About Multiple Warning Lights?

Seeing several warning lights at once can be alarming, but it doesn't necessarily mean several unrelated systems have failed.

One electrical or charging problem can sometimes trigger multiple warnings because modern vehicles depend heavily on electronic control modules and stable voltage.

For example, a charging-system problem can cause the battery light to appear and may also trigger other warning messages.

The important thing is to look at what changed at the same time.

If several red warnings appear and the vehicle is overheating, losing braking ability, losing steering assistance or running badly, stop somewhere safe and get help.

Don't keep driving simply because the engine still starts.

When Repairs Start Making Less Sense

A warning light doesn't automatically mean a car belongs in the scrapyard.

A $50 sensor on an otherwise healthy vehicle is a very different situation from a 15-year-old car that needs an engine repair, transmission work, suspension components, tires and extensive rust repairs.

That's when the numbers become important.

Before spending thousands on an older vehicle, consider its current market value, repair estimate, mileage, rust, previous maintenance and how likely another major repair is to follow.

If the repair bill is getting close to what the car is worth or the vehicle has become unreliable enough that you're constantly paying for the next problem it may be worth looking at alternatives. For an unwanted, damaged or end-of-life vehicle, scrap car removal can be a practical option when continuing to repair the vehicle no longer makes financial sense.

Don't Get Used to the Warning Light

One of the worst things you can do with a dashboard warning is become accustomed to seeing it.

A light that's been on for three months starts to feel like part of the dashboard. That's when it becomes easy to forget that it appeared because the vehicle detected a problem.

You don't need to panic every time a warning appears.

You do need to find out what it means.

Check the owner's manual, pay attention to whether the light is red, amber or flashing, and notice whether the vehicle is behaving differently.

A warning light doesn't necessarily mean an expensive repair is waiting for you.

But ignoring it guarantees that you won't know what the problem is until something else happens.

And by then, the repair may be considerably less convenient and considerably more expensive.