Modern cars have more warning lights than ever, and seeing one illuminate on your dashboard can cause anything from mild concern to full-blown panic. But not all warning lights are created equal — some demand you stop immediately, while others simply inform you of a routine status change.
This guide explains what the most common dashboard warning lights mean and exactly what you should do when they appear.
What Do Dashboard Warning Light Colours Mean?
Before diving into specific lights, it helps to understand the universal colour system used by all car manufacturers:
- Red: Stop driving as soon as it is safe to do so. Red lights indicate a serious or potentially dangerous problem.
- Amber/Yellow: Caution. Something needs attention, but it is generally safe to continue driving to your destination or to a garage.
- Green/Blue: Informational. These lights confirm that a system is active, such as indicators or cruise control.
Which Red Warning Lights Require Immediate Action?
Engine Temperature Warning
Symbol: A thermometer submerged in liquid
This light means your engine is overheating. Pull over as soon as it is safe, turn off the engine, and wait for it to cool down completely before checking the coolant level. Continuing to drive with an overheating engine can cause catastrophic damage including a cracked head gasket or warped cylinder head.
Common causes: Low coolant, failed water pump, stuck thermostat, radiator fan failure.
Oil Pressure Warning
Symbol: An oil can with a drip
This does not mean your oil is low — it means your oil pressure is dangerously low. Pull over immediately and turn off the engine. Running an engine without adequate oil pressure will cause severe internal damage within minutes.
What to do: Check the oil level with the dipstick. If it is low, top up before restarting. If the level is fine but the light stays on, do not drive the car — have it recovered to a garage.
Battery/Charging Warning
Symbol: A battery with positive and negative terminals
This light indicates that the charging system has failed. Your car is running on battery power alone, and the battery will eventually go flat. You may have 20–30 minutes of driving before the car dies.
Common causes: Failed alternator, broken serpentine belt, loose battery terminals.
Brake System Warning
Symbol: An exclamation mark inside a circle
Check your handbrake first — this light also illuminates when the handbrake is engaged. If the handbrake is off and the light is on, it could indicate low brake fluid or a fault in the braking system. Have it checked immediately.
What Do Amber Warning Lights Mean on Your Dashboard?
Check Engine Light (EML)
Symbol: An engine outline
The most common amber warning light, and often the most misunderstood. It can indicate anything from a loose fuel cap to a failing catalytic converter.
The only way to know what triggered this light is to read the fault code stored in your car’s ECU. With Cars Guru and an OBD2 adapter, you can read the code in seconds and get an AI-powered explanation of the problem, its severity, and recommended actions.
ABS Warning
Symbol: The letters “ABS” inside a circle
Your Anti-lock Braking System has a fault. Your brakes will still work normally, but the ABS will not activate in emergency braking situations. Have it diagnosed as soon as possible, especially in wet or icy conditions.
Tyre Pressure Warning (TPMS)
Symbol: An exclamation mark inside a flat tyre shape
One or more tyres are significantly below the recommended pressure. Check all four tyres (and the spare if applicable) at the next available opportunity. Driving on underinflated tyres increases fuel consumption, reduces handling, and accelerates tyre wear.
Engine Management Light
Symbol: Similar to check engine but may be steady or flashing
A steady light suggests a non-urgent issue. A flashing engine management light is more serious and usually indicates a misfire that could damage your catalytic converter. Reduce your speed and avoid heavy acceleration until the issue is resolved.
What Are Green and Blue Dashboard Lights For?
These are nothing to worry about:
- High beam indicator (blue): Your full beam headlights are on
- Indicator arrows (green): Turn signals are active
- Cruise control (green): Cruise control is engaged
- Eco mode (green): Eco driving mode is active
- DPF regeneration (amber on some cars): Diesel particulate filter is cleaning itself — keep driving at motorway speed for 10–15 minutes
What Should You Do When a Dashboard Warning Light Appears?
- Identify the colour. Red means stop; amber means investigate; green means information only.
- Check your owner’s manual. Every warning light is documented with specific instructions for your car model.
- Read the fault code. If it is a check engine or engine management light, use Cars Guru to scan for diagnostic trouble codes and understand the issue before deciding on next steps.
- Do not ignore it. Warning lights do not fix themselves. Even amber lights can escalate to serious problems if left unchecked.
How Can You Decode Warning Lights with an App?
Dashboard warning lights do not have to be mysterious. Download Cars Guru to read your OBD2 fault codes, track your maintenance history, and get AI-powered explanations of any issues your car reports. Knowledge is the best tool for keeping your car safe and your repair costs down.