Dashboard warning lights are not always easy to understand. The symbols used can be confusing and offer the driver little knowledge on what to do.
Dashboard Warning Light Colours
To help with this, dashboard warning lights are colour-coded. The colour of a warning light offers no specifics, but does provide the driver with a level of importance and urgency for the potential fault.
Blue Warning Lights
Blue dashboard warning lights are usually only associated with full / high beam headlights being in operation, or that something is cold, such as the engine coolant.
Green Warning Lights
Green dashboard warning lights are used to inform the driver that a vehicle utility device has been turned on and is in operation.
Amber or Yellow Warning Lights
Amber or yellow dashboard warning lights are usually a secondary warning informing that a system or engine requires servicing or maintenance. Amber lights may also be illuminated when something has been deactivated manually when by default, it is active.
Red Warning Lights
Red dashboard warning lights are primary warnings. Anything illuminating in red requires immediate investigation. To bring greater attention to the driver, a red light may also flash and/or be accompanied by an audible alarm.
Car Fault Codes
When a fault is detected, a warning light is produced along with a fault code. Some vehicles display the fault code, whilst others store it in memory but do not display it. If the warning light is generic and has many potential faults associated with it and if your vehicle doesn’t display fault codes, you’ll either need to have the codes read by an engineer using their own diagnostic equipment, or you’ll need to use your own.
If you’re willing and able to repair your own vehicle, diagnostic equipment is a must. Modern diagnostic code readers are easy to use and are now affordable. Conducting a search online will display the many models available.
Dashboard Warning Lights Explained
Here we will go through dashboard warning lights for all makes and models of cars and vans. An explanation of what the dash symbol means and what you need to do is given.
Stability Control Warning Light
Stability control, also known as Dynamic Stability Control (DSC) or Electronic Stability Control (ESC) is a safety feature that that uses various sensors and helps to stabilise a vehicle when a loss of stability has been detected. Stability control dashboard light may either come on constantly or flash. For more information, see What ESC is in Cars and How Does ESC Work in Cars.
Stability Control Warning Light Meaning
Constantly on: Stability control has been manually deactivated or if stability control has not been manually deactivated, there is a fault with the system. Likely fault is a sensor and diagnostic equipment will be required. You can continue to drive, but this safety feature will likely be disabled.
Flashing: Stability control has detected instability and is actively engaged.
Check Engine Warning Light
The check engine light or malfunction indicator light (MIL) is a generic warning symbol that has many potential faults associated with it. The check engine dashboard warning light looks serious but is usually nothing too urgent. You should still have the fault looked into though as in some cases, there is the potential for component damage. The light will come on constantly or flash.
Check Engine Warning Light Meaning
Constantly on: Often associated with an emissions fault and an incorrect fuel mixture. This will emit harmful exhaust emissions and will likely increase fuel consumption. Other faults are often due to a faulty sensor. This is not an emergency but should be diagnosed and fixed as soon as possible.
Flashing: If the light is flashing, your vehicle requires immediate attention. This is often an indication of an engine misfire, where unburnt fuel is dumped into the exhaust. This causes extreme temperatures and can damage the catalytic converter.
Limp Mode Warning Light
Similar to the check engine or engine management light above, limp mode is a protective safety feature that lowers the engine power output when a fault has been detected, therefore reducing the potential of damage. Diagnostic code readers are required to locate the fault.
Limp Mode Warning Light Meaning
Often related to faulty valve / incorrect fuel mixture causing engine misfire. Possible faulty sensor. Have vehicle checked as soon as possible. For more information on why this light may have come on, see reduced engine power warning light.
Traction Control Warning Light
Traction control is a safety vehicle system that uses sensors to determine if one or more tyres has lost traction with the road surface. In the event of a loss of traction, the brakes are automatically pumped quickly until traction is regained. Your vehicle may have an independent traction control system, or it may be part of the stability control system (see above).
Traction Control Warning Light Meaning
Traction control can in most vehicle be switched off. You can also switch off stability control, which in turn will also disable traction control. In this instance, the traction control (or stability control) light will comes on. If you have not manually switched off the system and light comes on, a fault has been detected and the system is disabled. See traction control dashboard warning light for possible faults.
Coolant Warning Light
This red dash warning light is telling you that the engine coolant temperature is too high. Severe risk of engine damage with continued driving.
Coolant Warning Light Meaning
As soon as it’s safe to do so, stop and switch off the engine. Allow several minute for the engine to cool and check engine coolant levels. Fill to the MAX. marker on the coolant header tank if required. Ensure you use the recommended antifreeze for your vehicle – even during hot months as it increases the boiling temperature of water. If coolant levels do not require topping up, it’s highly advised that you do not continue your journey. For further information, see red engine coolant warning light on or flashing.
Brake Warning Light
This red exclamation mark contained in a circle has slightly varied meanings based on each car manufacturer. This dashboard warning light may also spell the word .
Brake Warning Light Meaning
- The manual handbrake is applied.
- If the handbrake is not applied, check brake fluid level as it may require topping up.
- If it is neither the handbrake or brake fluid, there may be a fault with the vehicle braking system.
Red Battery Warning Light
The red battery warning light comes on as a bulb check briefly when the ignition or engine start button is switched to ‘on’. It should go out when the engine starts. If the battery warning light stays on or comes on while driving, there’s a fault with the electrical charging system.
Red Battery Warning Light Meaning
If the battery warning light comes on while driving, immediately turn off any systems or utilities that are not essential and that draw electrical power. If the battery becomes exhausted, it’s likely the engine may stop. Make your way immediately to a vehicle repair shop. See why is my car battery warning light on for further information.
Yellow Battery Warning Light
Along with the red battery warning light, some vehicles also come equipped with a yellow battery warning light. If the yellow battery warning light illuminates, it means the battery has a low state of charge.
Yellow Battery Warning Light Meaning
Leaving the battery to charge overnight will fix the yellow battery warning light issue or a long car journey. Frequent short journeys do not allow the battery to charge properly. If the yellow warning light comes back on after fully charging, look into possible faults of a red warning light detailed above.
ABS Warning Light
Anti-lock braking system or ‘ABS’ is a feature that helps the driver to keep control of the vehicle under heavy braking. It does this by preventing the wheels from locking and as such, allows the driver to continue to steer and control the vehicle.
ABS Warning Light Meaning
The presence of the ABS light means this function is no longer in operation. ABS is an ‘add-on’ to standard brakes and therefore standard brakes continue to work as usual. Be cautious until you have the system fixed as heavy braking may result in the wheels locking.
EBD Warning Light
Electronic Brake Force Distribution (EBD) is another braking aid. Varied amounts of braking force are applied on a per-wheel basis depending on the road surface which results in the best possible traction. If a fault is detected, your vehicle may have a dedicated EBD dash light or a combination of or +
EBD Warning Light Meaning
If your vehicle has an EBD fault, have it checked immediately. Vehicle may become dangerously unstable.
ABS Warning Light
The air bag or ‘airbag’ dashboard warning light should go out shortly after engine ignition. If the light comes on when driving or does not come on at all during ignition, there is a fault with the air bag system. In many vehicles, this light is also associated with SRS (Supplementary Restraint System) and your vehicle may display a ‘SRS’ warning light. Seat belt pretensioner faults can occur.
ABS Warning Light Meaning
It’s unlikely that the air bags will be deployed in the event of a collision. Have diagnostic equipment connected by an engineer to establish faults codes to fix the fault.
Seat Belt Warning Light
The seat belt dashboard warning light illuminates on the majority of vehicles and will usually emit an audible alarm if any vehicle occupants do not fasten their belt.
Seat Belt Warning Light Meaning
Seat belts help to reduce fatal injury to front seat passenger car occupants by 45% and risk of moderate-to-critical injury by 50%
Oil Temperature Warning Light
The oil temperature dashboard warning light is high to the point that internal engine components may give way.
Oil Temperature Warning Light Meaning
Reduce the engine load of your vehicle and if possible, stop, switch off the engine and allow some time for the engine oil to cool. For possible reasons why this warning light is illuminating, see oil temperature warning light.
Tyre Pressure Warning Light
The tyre or ‘tire’ pressure under inflation dashboard warning light, or tyre pressure monitoring system (TPMS) illuminates when one or more tyres is significantly under inflated.
Tyre Pressure Warning Light Meaning
Stop as soon as safely possible and check tyres. Re-inflate the affected tyre or change over with the spare if necessary. Tyre (tire) pressures should ideally be checked when cold. For further information on what cold tyre pressure means and how to check tire pressures when cold or hot, see cold tyre pressure explained.
Brake Pads Warning Light
Not all vehicles come equipped with a worn brake pads warning system. If you see this warning light, your vehicle has an electronic brake pads wear sensors that alert the driver when the remaining pad levels are low.
Brake Pads Warning Light Meaning
The low brake pads warning light requires you to have the brake pads changed soon. See worn / low brake pads warning light for further information.
ASR Warning Light
ASR is a type of traction control and vehicle stability system used by certain car manufacturers. At each ignition cycle, ASR is activated, but can be disabled by use of the ASR OFF button, or by navigating through the options on the display panel.
ASR Warning Light Meaning
It’s almost always beneficial to leave ASR switched on. If you switch off the ASR system, the ASR OFF warning light displays on your dashboard. For further information on ASR, what it is and when it is beneficial to switch it off, see ASR on a car explained.
Low Outside Temperature Warning Light
The low outside temperature warning light / snowflake symbol indicates that their may be frost on the road.
An external sensor on your vehicle monitors outside temperatures and triggers the snowflake warning light when temperatures fall to around 3°C. For further information on the frost warning light, see snowflake dashboard warning light explained.
DPF Warning Light
In order to curb harmful emissions, most diesel cars have been fitted with diesel particulate filters (DPF) since 2009. A DPF collects harmful diesel soot and traps it. After a predetermined time, detected by sensors within the filter, it requires cleaning, either passively, actively or by forced regeneration.
Diesel particulate filters can cause issues for driver of diesel vehicles, particularly those that mainly take short journeys. For further information on the DPF and how to regenerate (clean) your filter by driving, see DPF warning light meaning.
Rear Fog Lights Warning Light
This symbol represents the rear fog lights being switched on.
Rear Fog Lights Warning Light Meaning
It is mandatory in the UK since April 1st 1986 that all vehicles are fitted with red rear fog lights. Fog lights must only be used when visibility is significantly reduced and must be switched off when parked. For further information on a car’s rear fog lights, how and when to switch them on a turn them off, see fog lights symbol and use.
Front Fog Lights Warning Light
This symbol represents the front fog lights being switched on.
Front Fog Lights Warning Light Meaning
Unlike rear fog lights, front fog lights are not a legal requirement. As with rear fog lights, only use front fog lights when visibility is significantly reduced.
Exterior Lights Warning Light
This dashboard light informs the driver that the exterior lights / sidelights / parking lights / headlights are switched on.
To prevent battery drainage, most modern vehicles lights switch off when the ignition key is turned to the off position. Some vehicles allow parking lights to remain on.
High Beam Warning Light
The high beam symbol is a blue symbol with five horizontal lines vertically stacked to the left of a shape that resembles a headlight. When traffic ahead is seen, high beam headlights must be switched to low / dipped beam to prevent dazzle to other road users.
The blue symbol will go off once the headlights are switched to low beams.
Automatic High Beam Warning Light
Automatic high beam headlights automatically switch between high main / beam and low / dipped beam. Most automatic high beam systems use a camera mounted behind the windscreen at the top centre.
If auto high beam lights are not working correctly, clean this area of the windscreen in front of the rear view mirror to ensure functionality.
Open Book Symbol
The symbol of an open book containing either the letter ‘i’ or an exclamation mark illuminates to refer you to your car owner’s manual. The symbol typically comes on along with a text message or a warning light. The open book symbol various in colour from white, black or yellow.