All car light symbols that every driver must know for sure

The instrumentation lights are color-coded pictograms that illuminate to prevent us from breaking the car or putting ourselves in danger.

What do the lights on the dashboard mean?

In a modern vehicle, it is possible to find about a hundred witnesses. We explain what each of them means.

In most cases, the only thing left of the original system is precisely the pictogram that allows them to be distinguished in the blink of an eye. These are the witnesses to the instrumentation: those luminous warnings that were born in the form of primitive telegraphs that allowed the driver to get a little more in contact with the mechanics.

Is there sufficient oil pressure? Is the level of the brake fluid reservoir correct? Am I given the low beam or the long beam? Currently, their meaning has not changed much … although the causes that can ignite them have multiplied.

Three decades ago, the brake fluid warning light came on when, a few centimeters away from it, a small sensor stopped being bathed in that hydraulic oil. Today, however, dozens of systems ‘access’ the brakes – from ESP, to perform more and more functions such as hill start assist to modern systems capable of avoiding a collision by range whenever you drive less than 30 km / h -… and can declare a fault.

In this sense, it is essential to become aware of how to react when a yellow or red warning light comes on in the instrumentation, or even if several light up at the same time and accompanied by whistles and sirens. If it happens, we will have to stop, but not immediately … but safely in the right first place. And nothing happens to travel three or five kilometers to find it. In other words, it is very important to prevent a warning about a possible breakdown from degenerating into a serious accident. It will be then, with the car stopped, when it will be time to find out what has broken, for example, comparing the pictogram that has been illuminated with these that we offer below. So remember: warning systems must be at your service. Never the other way around.

Car dashboard symbols and meanings

Braking system

Brake system warning light

  • The most common reason it lights up is if the brake fluid level is low.
  • If it lights up in gear, feel the brake pedal: if you have lost a lot of fluid or one of the two circuits has emptied, you may have to press the pedal very hard to stop the vehicle, and the car will tend to drift. aside, so that it tries to do it straight.
  • This warning light also lights up if systems that use the brakes like the Hill Holder – hill start assistant – or the BAS emergency brake servo break down.

Hand brake

Parking brake warning light

  • It indicates that the parking brake is applied.
  • On cars with a manual parking brake, the warning light serves to remind you to release it before driving … but it does not guarantee that it is applied correctly!
  • In vehicles with an electric parking brake, it does mean that it is properly applied, and it is very important to check when leaving the car that the warning light stays on.

Brake pads

Brake pads

This witness is distinguished from the first two in the amber color, in that there is nothing written inside it and in which the parentheses are discontinuous lines. It comes on when one of the brake pads has worn out and the small conductor they fit inside has begun to make contact with the disc. Automatically shuts off when replacing pads.


ABS warning light

This warning light indicates a fault in the anti-lock braking system.
  • Along with it, the stability control icon lights up, which cannot work without ABS.
  • In addition, electronic brake sharing and electronic differential lock functions are also disabled. Contrary to when the ESP intervenes, the ABS warning light does not flash when the system intervenes.
  • The fault is usually in one of the sensors that measure the rotation of the wheels, and the repair is around 70 euros.

Oil pressure

Oil pressure warning light

The oil pressure at the pump outlet is less than the minimum necessary to lubricate the motor.

  • In cars without Stop? T, it lights up when the ignition is turned on and stays on until we start the engine.
  • With the engine started, the most likely reason for it to light up is that there is hardly any oil in the crankcase – the first few times, it usually blinks briefly while tracing a sharp curve.
  • Driving with this warning light on can cause seizures – due to the heat of the friction the parts start to melt and can seize the motor.

Coolant temperature

Coolant temperature warning light

This warning light is usually controlled by the coolant temperature sensor, although it will also light up if the engine warms up because there is no coolant or the level is very low.

  • If the instrumentation does not have a thermometer, there is usually this second warning light, which reports that the engine is cold. lIf you have a thermometer, the first icon is usually replaced by a lighted mark at the end of the scale.
  • A ‘heater’ is not always a sign of failure or has consequences if you react by slowing down immediately, stopping and letting the engine cool down. Often the solution is to clean the radiator.

Alternator failure

alterndor failure

This warning light stays on with the ignition on and the engine stopped – except in cars with Stop? T, for comfort.

  • If it turns on with the engine running, it means that the alternator – the one in charge of charging the battery and providing electrical power to all the car’s systems – is not generating enough voltage.
  • It is not a dangerous situation, but the battery will be fully discharged even if you are driving. If you stop the engine, you won’t be able to start it again. If the alternator is heavily ‘touched’, it may stop running.

Power steering

Power steering

Indicates a failure in the power steering assistance system that can range from not significantly affecting assistance to system disconnection. Driving without power steering is possible, but not recommended: not only because of how hard the transmission will be but also because working “backwards” can damage the transmission mechanism.



Depending on the age of the car, there may be a witness for all airbags or one for each type. Often the fault is not in the airbag, but in the connections – especially if it’s a seat-mounted one.

Seat belt

Safety belt witness

This witness does not report a fault, but rather that an occupant is not wearing a seat belt. It lights up, along with an acoustic warning, when the car a) exceeds 25 km / h, b) has traveled 500 meters, c) has been in motion for more than 60 seconds. The acoustic warning is deactivated after five minutes, but the warning light does not go out. It is possible to ask the manufacturer for instructions to deactivate this system.

Auto switch

This icon is often used when a breakdown occurs in an automatic gearbox or an all-wheel drive system with a gearbox or lockable differentials. When the fault affects the gearbox, an ’emergency’ mode is usually activated in which only three gears operate.

Particulate filter

particle filter

This witness is only found in instrumentation for diesel-powered cars.

It is controlled by the difference in pressure before and after the particulate filter, it indicates to the driver that he must carry out a particular driving – high speeds and short gears – to get clean.

Ignoring it can be very expensive: if too much carbon accumulates in the filter, it will have to be replaced … which will cost from 700 euros.

Emission anomaly

Emission anomaly

Flashes when abnormal parameters are recorded in engine management, injection system, ignition system, or exhaust.

  • If it blinks, it is important to stop accelerating as soon as possible; otherwise, exhaust components can be damaged by overheating.
  • An ’emergency’ engine mode -o limp mode- may be activated which provides greatly reduced performance.
  • If the anomaly is prolonged for a long time, the warning light stays on permanently, indicating that an incident has been recorded in the engine control unit and that a workshop should be visited to find out what has happened.



This icon flashes whenever the stability control intervenes by selectively braking the wheels – in many Japanese cars, an acoustic warning also sounds – and stays on if the stability control is disabled or suffers a failure.

Tire pressure

Tire pressure warning light

By law, currently all cars must have a system capable of detecting a flat tire.

  • Almost all models use a system that detects that one of the wheels rotates slower than the others, this warning light turns red – the driver should then try to find out which one is flat.
  • For the system to work, it needs to be ‘initialized’ every time the wheel pressures are adjusted – during that process, the system ‘learns’ the wheel radius.

Fuel level

Fuel warning light

It indicates that the remaining fuel level is low -generally, it is activated when the autonomy falls below 80 kilometers or, if the car consumes a lot, a little below 1/4 tank-. Generally, the side where the hose is indicated in the pictogram matches the side of the car where the filler cap is located. In addition, there is usually an arrow next to the fuel gauge icon indicating this.

Ice on the road

Ice on the road

More and more cars are incorporating a witness like this … or that show it on the instrumentation screen. It comes on when the temperature drops below three degrees Celsius.

Defective bulb

Defective bulb

In many cars, when a bulb burns out, a light like this lights up. Depending on the degree of sophistication, the system can identify the burnt out bulb more or less accurately – by means of a message on the multifunction screen.

Stop / Start not available

Stop / start

It shows in the instrumentation when the driver voluntarily deactivates the system that stops the engine while the vehicle is stopped or there are circumstances in which the system cannot function. This is what happens when, for example, the engine has not yet reached the operating temperature or the air conditioner has been adjusted to a very low temperature.

No windshield washer fluid

The sensor for the liquid wash tank detects that it has run out.

Recommended rest

More and more cars incorporate a system that analyzes the movements of the steering wheel and detects when the driver seems to be drowsy or exhausted. So, this icon lights up in the instrumentation, along with a legend that recommends pausing and resting.

Long lights

Road lighting on. It is blue because it is the color that stands out the most at night.

Automatic high beam

The high beams are in automatic mode and come on as soon as the camera that controls them detects that they will not dazzle anyone.

Recommended gear

Currently it is mandatory that all cars have a recommended gear indicator … although there is a wide variety of icons. This is the one used by Opel.


The lane departure warning system has an icon that changes color. It is orange while it is on, and it lights up green when it detects the lines and starts working.

Cruise control

In green, it means that the system is on and maintaining the programmed speed. If it is a radar cruise control, this other icon is often used.

Blind Spot Assistant

Unlike the LDW warning light, this icon lights up green when the system is active … and only lights up amber when a fault is detected.

Apply the brake

This pictogram can only be seen on board cars with automatic transmission. It lights up amber when the lever is in position P, indicating that to move it it is necessary to apply the brake. As you do so, the lamp turns green. This security system, called Interlock, prevents an automatic car from starting to move without anyone sitting behind the wheel.

Front and rear fog lights

It is distinguished by the undulating vertical line. The front fog lights, the line points downwards, implying that it is a short-range light. The rear fog lights are amber because if used without fog, it is very annoying for other drivers.

Some special cases



Because every time you start the car, the systems to which they belong carry out a small self-test routine and, if everything is correct, send a message through the car’s data network that tells the instrumentation that everything is OK and that it can turn them off. This function allows checking in vehicle inspections that the witness is operational.


Some manufacturers offer an ‘electronic self-locking differential’ – a feature that, when accelerating, stops the skidding wheel to transfer torque to the opposite wheel on that axle. This function is not deactivated by the driver. That is to say, it remains active even if you disconnect the ESP … and, when the system intervenes, it records the extinguishing of the warning light, which is on. Other non-deactivatable ESP functions are ABS and brake distributor.


No, because they are not standardized. Although some countries, like the US, set some standards. For example, in the USA the brake fault light must have the BRAKE legend.


If it is German, it surely does not have: the cars that have a control for the lights on the dashboard -the one in the photograph is of an Audi A6- usually do without the indicator of lights on for those of position and crossing.

About the Author: luis

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