Everything under control?

In the past, there were only a few different warning lights in the car: alternator, coolant and oil pressure – that was it. Today, the number of warning lights is much higher, and indicates to us with different colours that something is wrong. But let’s face it – do we always immediately know what these symbols indicate? Probably only those who, in addition to the coloured symbols, get an additional explanation in the form of a text message. But even then it is not always immediately clear how severe the problem is. Some error messages require immediate action and a visit to a workshop, while others can threaten the vehicle.

The general rule:

Yellow and red indicate problems and functional failures. It is advisable to leave the car immediately when a “red lamp” lights up. Green icons indicate the function or readiness of systems which can be turned on and off such as cruise control or lane departure warning. White symbols indicate, for an example, the start-stop system or the parking aid.

The blue colour is reserved for the high beam. This colour scheme is uniformly defined. However, as far as the symbols are concerned, some automakers may use others than the ones shown in the following illustrations.

The most important red indicator lights at a glance


This light indicates that the battery is no longer being charged by the alternator (generator). This can have several reasons: the v-belt is cracked or the alternator, battery or regulator is defective. You should immediately remove the vehicle as it is often that the coolant pump driven by the V-belt fails the cooling.

Parking brake: 

If this symbol comes on, there are two possible reasons. Either the parking brake is still applied, which is often additionally accompanied by an acoustic signal, or the brake fluid reservoir contains too little brake fluid or is empty. In this case, you should stop immediately and inform a specialist workshop.

Brake pad wear: 

This symbol indicates that the wear limit of the brake pad has been reached. Have the documents exchanged at a specialist workshop.

Oil pressure control: 

The oil signalizes when oil pressure is too low – a pot with underlying wavy lines asks for checking the oil level. Stop the engine and wait a few minutes to measure the oil level on the dipstick. If necessary, top up with oil and visit a workshop.


The coolant temperature is too high. Immediately stop the engine and allow it to cool. Then check the coolant level. Before refilling water or coolant, be sure to read the operating instructions on how to open the container without danger. Since the container is under pressure, there is a risk of scalding! If the symbol continues to glow despite sufficient coolant, the vehicle must be checked in the workshop. 

Engine diagnostics: 

This indicates that there is a fault in the engine electronics or in the exhaust system. This can lead to reduced performance and increased environmental impact. Find a workshop immediately!


Airbags or belt tensions can accidentally trip or fail in the event of an accident. Have the restraint system checked by a specialist workshop.


If this symbol is lit, the ABS has failed due to a malfunction. ESP, brake assist, electronic brake force distribution and the tire pressure monitoring system will also stop working properly. Visit a specialist workshop immediately.

The most important yellow indicator lights at a glance


When this light is flashing, Electronic Stability Program or Traction Control is working. If the symbol is lit permanently, the ESP is switched off. If the ESP does not turn on again, visit a specialist workshop.

Tire pressure:

This lights up when the tire pressure is low or if there is a problem with the system. The system uses the ABS sensors to compare the rolling circumference of all four wheels with a set point. Immediately check the air pressure of the affected tire.

TUV NORD Mobility Inc.

Suite 415, 708-11th Avenue S.W.
Calgary, AB, Canada
T2R 0E4