Dashboard Warning Lights

What does the lights on the dashboard mean?

There is an English idiom saying, “A picture is worth a thousand words”. This idiom is very relevant here when we are about to discuss dashboard warning lights. The rhetorical question we should ask is how many vehicle owners fully understand the meanings of these warning lights?

We at the SAC Service Centre are a caring bunch of people. It warms our hearts when our readers and customers (all family members of this group) have the relevant knowledge when it comes to vehicle related issues. A well-informed individual can easily identify an issue, act upon it, and be a responsible vehicle owner because of a broader vehicle component knowledge base. We do not want to see you admiring your vehicle’s engine on the side of any road (due to a breakdown). Dashboard warning lights has been in vehicles for a very long time, but there were surely not as many as there are today. These warning lights go on for a reason. We will therefore acquaint you with the reasons behind an illuminated dashboard light. It will be worth mentioning that warning lights may vary depending on a vehicle’s make and model. They differ not only in picture but also in colour. The colour is however mostly more consistent than the picture is.

Different Colour Codes

A dashboard warning light may represent itself in any of the normal traffic light colours, and they will have a similar warning.

RED warning light may indicate a potentially serious issue but it can also remind you of a maintenance that is due. STOP – never ignore a red warning light.

YELLOW or ORANGE light is usually a sign that something needs attention. This colour is not as serious as the red one but proceed with CAUTION and have the issue addressed.

A GREEN or BLUE light usually indicates that a system is active and operating, so everything is a GO.

Now that we know the colour differentiation, let us look at the warning symbols themselves. There can be more than 60 symbols, but for the purpose of simplicity, we will touch on the symbols most commonly found. Enjoy the ride!

Some Common Warning Lights

Check Engine

Engine Light

This indicates an engine issue. When this light comes on, you may usually feel that something is not quite right with the vehicle. The issue may be minor or even a major one. Something important to take note of is that the check engine light is part of your vehicle’s on-board diagnostics (OBD) system. When this system discovers a problem it cannot fix itself, then the light will go on. The engine control unit (ECU) will store a trouble code that can be retrieved by way of a diagnostic test. The diagnostic trouble code (DTC) will identify the probable source of the engine problem. Whenever the check engine light comes on, be sure to have it checked out as a priority.

Reduced Power

Engine Electric Warning

This warning light will draw your attention to a loss in power. Most vehicles are pre-programmed to limit vehicle performance in order to prevent system/component failure. The ECU will start to limit (reduce) aspects such as engine power, speed, etc. Some sort of engine or transmission trouble may cause this light to come on. This warning should not be taken lightly. Have it diagnosed and fixed.

Battery Alert

Battery Warning

Check the battery; it may indicate a faulty battery or even an alternator not charging correctly. It may even indicate a loose connection. Whichever the case may be, the voltage is clearly too low so consider switching off any unnecessary accessories and have the battery and other possibilities inspected as soon as possible.

Coolant Temperature

Coolant Temp Warning

When you see this sign, it means that the coolant temperature is warmer than it is supposed to be. Seize driving and let the vehicle cool down first, then determine why this happens. You may consider looking at the coolant fluid level, see if there is any leaks, and make sure the fan is operational, you may even check if the radiator cap is well sealed. When the sign is blue, the coolant temperature is below the required temperature. It usually turns red after a short drive, when it reached the required temperature rate.

Transmission Temperature

Gearbox Temp Warning

You surely do not want to entertain costly transmission troubles. This light will tell you that something is wrong down there because the transmission is operating at higher than accepted temperatures. Check the transmission fluid and let us have a look at it if the problem persists.

Oil Pressure Warning

Oil Pressure Warning

The vehicle has lost normal oil pressure. Oil lubricates the components in your vehicle. A lack of decent lubrication means excessive friction and excessive heat. These are detrimental to any vehicle. Check the oil level and have the vehicle inspected when you see this warning light because this may indicate a serious issue.

Vehicle Service Required

Service Warning

This symbol is dependent on a vehicle’s make and model. The body control module (BDM) is responsible for monitoring and controlling electronic accessories in a vehicle’s body. When this warning symbol comes on, then it may indicate a faulty headlight, turn light or other light issue. The symbol is also responsible for the indication of faults in the vehicle’s chassis or brake system. The light may also indicate that it is time to have your vehicle serviced. Rather be safe and have it checked out, than be sorry.

Tyre Pressure

Tyre Pressure Warning

This sign may also be referred to as the TPMS (tyre pressure monitoring system) and it will indicate that one or more of your vehicle’s tyres are running below its required pressure. Your tyres keep you and the vehicle on the road, correct tyre pressure is therefore very important. Check them and if necessary, rectify the problem.

Brake System

Brake System Warning

Check the handbrake and make sure that it is not engaged. The sign may also indicate low brake fluid or even something more severe in the braking system. Keep in mind that your vehicle’s brakes are one of the most important feature on your vehicle, so whenever this light is on, it is best to get it checked out right away.

Anti-lock Braking System (ABS)

ABS Warning

Something is not well with the ABS. This might be life threatening, especially if you need to execute an emergency stop. Have the system diagnosed by one of our professional technicians/mechanics as soon as possible.

ESP Fault

ESP Warning

ESP stands for Electronic Stability Program and is an important safety system in vehicles. This symbol will also indicate a BAS (Brake Assist System) problem. The ESP and BAS systems work together; a fault in either or both will cause the light to come on. ESP has a dedicated warning light, which is a vehicle with skid marks, as pictured below. If this light stays on, it may indicate a fault in the stability system, so have it checked out.

Traction Control

Traction Control Warning

No, it has nothing to do with a drunk driver in front of you. It warns you about your traction control losing its grip. Read the relevant information given in the ESP Fault dashboard light, as discussed above, and have this rectified.

Electric power assisted steering (EPAS/EPS)

Power Steering Warning

This warning light is an indication that there is a fault with the power steering system. Usually the power steering system will not be functional until you get it fixed. The steering could go heavy and more effort will be needed to steer the vehicle.


Overdrive Off Warning

The overdrive light will inform you that the overdrive system has been turned off. If the overdrive light is blinking, it is an indicating that there is a problem with your vehicle’s transmission. Whether it is the solenoid or the speed or range sensors that is making the light to illuminate, do attend to this problem by having it checked. It may be a serious fault, especially when it comes to your vehicle’s transmission system.

Security Alert

Security Alert Warning

This may indicate a locked ignition key. A proper transponder-equipped key will be required to sort this out. This fault may make your vehicle susceptible to theft. Have this fixed as soon as possible.

Door Ajar

Open Door Warning

Not only a door, but also an unclosed trunk or hood, may be the cause of this light being on. Imagine if any of the said “doors” are left open and the light stays ignited the entire day. This may drain your vehicle’s battery and leave you stranded.

Lamp Out

Lamp Out Warning

This will inform you of an exterior light that has gone out or that is not functioning properly. Check the lights on your vehicle and if you cannot see an obvious dead lamp, then have this fault checked by a specialist.

Washer Fluid

Washer Fluid Warning

It is unfortunately not an indication that you are nearing a fountain. It simply reminds you that the windshield washer fluid is low; top up the washer fluid and check for any leaks.

Airbag Fault

Airbag Warning

The airbag is a safety design. If there is an issue with the bag, it will jeopardise your safety, not only with regard to NOT deploying when it should, but also with regard to maybe deploying when it should not! The best advice to give whenever this sign appears is to bring your vehicle to one of our branches and have the airbags investigated.

Glow Plug (Diesel Only)

Glow Plug Warning

Apart from having glow plugs in your vehicle, you also have a glow plug light that will either come on and stay on, flash or blink whenever a glow plug fault is detected by the ECU. The ECU will store the relevant information about the fault and this information can be retrieved by way of a diagnostic test. Sometimes, when this light comes on, the engine will go into “safe” mode in order to prevent any damage to the engine. Get a diagnostic check done as soon as possible in order to determine the problem and correct it.

Diesel Particulate Filter (Diesel Only)

DPF Warning

Your vehicle’s engine control unit (ECU) constantly monitors the soot levels inside the filters. A diesel particulate filter (DPF) removes the soot from the exhaust gasses in order to reduce harmful emissions. If the engine is not able to burn the soot (due to repeated short trips or a faulty DPF), the computer will turn the warning light on to warn you about this. If you know you drive many short trips with your vehicle, and the light comes on, then it is advisable that you take your vehicle out on an open road or highway and drive it for at least ten minutes at not less than 70 km/h. This may turn the light off. If the light is on due to a faulty DPF, then it is another story. A faulty or blocked DPF will put your vehicle in “limp” mode. It may also damage your engine and result in a toxic outlet of black smoke from the tailpipe. It will be more costly to fix it than having it checked if the light fails to go off.

Diesel Exhaust Fluid (Diesel Only)

Exhaust Fluid Warning

Diesel exhaust fluid (DEF) is a component that helps to clean up diesel emissions. Whenever the reservoir of the vehicle’s DEF is low, this light will come on. If you ignore the light, you will either not be able to start your vehicle or your vehicle will most likely enter a “limp” mode (snail’s pace). The DEF light can also indicate contaminated fuel. Have your vehicle diagnosed by one of our certified technicians if the light continues to stay on, even after you filled the DEF container.

This brings us to the end of this discussion. We also have listed the 64 most common dashboard warning lights which you can read by click here. We hope that the information supplied here will be helpful to you. A word of wisdom:

Ignoring dashboard lights are risky


Vehicles become more and more sophisticated and the possibility of faults has grown exponentially. So has the warning lights, from a few basic lights way back to a plethora of warning lights. Always remember, your warning lights are trying to tell you something, and determining whether the message is serious or of little consequence, is sometimes best left to a qualified mechanic. You may greatly reduce the appearance of warning lights if you practice regular vehicle management and care. However, you may self-service your vehicle as much as you like, and care for it in the best way possible, but components are components and things break. If you experience dashboard warning light issues, then feel free to visit a Steves Auto Clinic; we possess all the labour, the knowledge, the equipment, and above all, the exceptional service to assist you whenever you require your vehicle to be diagnosed and/or simply be checked whenever a dashboard warning light rear its colourful head!