Dashboard Warning Lights: Red, Amber and Green Explained
Learn what red, amber and green dashboard warning lights mean, what to do for each, and when to book a car repair near me.
Dashboard warning lights follow a simple colour code: red means a serious problem, so stop safely as soon as you can; amber means get the car checked soon; green or blue is information only. If a red or amber light stays on, booking a car repair near me for a proper diagnostic check is quicker and cheaper than waiting for the fault to grow. Knowing which colour you are looking at tells you how fast to act.
This guide explains the colour system, the red and amber lights that matter most, and exactly what to do when each one comes on. Symbols vary slightly between manufacturers, so your handbook is always the final word on your own car.
How the warning light colour system works
Most modern cars use the same traffic-light logic. Learning it means you can make a sensible decision in seconds, even if you do not recognise the symbol.
- Red: a serious fault or safety risk. Find a safe place to stop, switch off the engine and do not carry on until you know what is wrong.
- Amber or yellow: something needs attention soon. You can usually keep driving carefully, but book a check within days, not weeks.
- Green or blue: information only, such as headlights, main beam or cruise control being on.
Two extra clues help. A light that flashes is usually more urgent than one that stays steady. And it is normal for most lights to glow briefly when you switch on the ignition as a bulb check; they should go out once the engine starts.
Red warning lights: stop safely
Oil pressure
Usually shown as an old-style oil can. It means the engine is not getting enough oil pressure, and running it like this can cause serious engine damage within minutes. Stop, switch off and check the oil level on flat ground once the engine has cooled. Even if the level looks fine, do not drive on until the cause is found.
Engine temperature
Often a thermometer in liquid. The engine is overheating. Stop and switch off. Never open the coolant cap while the engine is hot, as the system is under pressure. A low coolant level, a leak or a failed fan or water pump are common causes.
Brake system
Typically an exclamation mark in a circle, sometimes with the word BRAKE. First check the handbrake is fully released. If the light stays on, the brake fluid may be low or there may be a fault in the system. Our guide to the brake warning light explains the possible causes.
Charging system
Shaped like a battery. It usually means the battery is not being charged, often because of an alternator or drive belt problem. The car will run on battery power for a short time, then lose power. Read what a car alternator does to understand why this matters.
Amber warning lights: get a check soon
- Engine management: an engine outline. Steady means a fault has been logged; flashing usually means a misfire, so reduce speed and get it checked promptly. A steady light will also cause problems at your MOT, as explained in our guide to the engine management light before an MOT.
- ABS: the letters ABS in a circle. Normal braking still works, but the anti-lock system may not help in an emergency stop.
- Tyre pressure (TPMS): a horseshoe shape with an exclamation mark. Check and adjust all four tyres when cold, then look for a puncture if the light returns.
- Airbag: a seated figure with a circle in front. The airbag or seatbelt pre-tensioner system may not work in a crash.
- Diesel particulate filter (DPF): a box with dots inside. The filter is getting blocked. A longer steady drive can sometimes help it clear, but check your handbook first.
Warning lights at a glance
| Light | Colour | What it usually means | What to do |
|---|---|---|---|
| Oil pressure | Red | Low oil pressure | Stop and switch off now |
| Engine temperature | Red | Overheating | Stop, let it cool, do not open the cap hot |
| Brake system | Red | Handbrake on, low fluid or brake fault | Check handbrake; if still on, do not drive |
| Charging | Red | Battery not charging | Stop safely and arrange a check |
| Engine management | Amber | Engine or emissions fault | Book a diagnostic soon; urgent if flashing |
| ABS | Amber | Anti-lock system fault | Drive gently and book a check |
| Tyre pressure | Amber | Low pressure in one or more tyres | Check pressures and look for damage |
| Airbag | Amber | Restraint system fault | Book a check promptly |
| DPF | Amber | Filter becoming blocked | Follow the handbook; book a check if it stays on |
Book a diagnostic check with a mobile mechanic or a trusted local garage, with a fixed price and live photo updates.
What to do when a light comes on
- Note the colour and whether it is flashing. This sets your level of urgency.
- Watch for other symptoms. Steam, smoke, burning smells, loss of power or a change in how the brakes feel all make it more serious.
- For red lights, stop safely. Pull over somewhere safe, switch on your hazard lights and switch off the engine.
- Do the simple checks. Handbrake, oil level, coolant level when cold and tyre pressures. Our guide on checking your car's fluid levels at home shows you how.
- Do not just clear the code. A cheap code reader can turn a light off, but the fault is still there.
- Book a proper diagnosis. A diagnostic inspection reads the stored fault codes and then tests the parts involved, so you fix the cause rather than guess.
Booking a car repair near me after a warning light
With Hon Car Service you enter your registration and postcode to get a fixed price with parts and labour included. You then choose a mobile mechanic at your home or work, free collection and return, or drop-off at a trusted local garage near me. You get live photo updates, any extra work needs your approval first, and your card is only charged after the work is done and approved. Repairs carry a 12-month parts and labour warranty.
We cover Southampton, Eastleigh, Totton, Hedge End, Chandlers Ford and Romsey, and drivers across the UK.
Frequently asked questions
Can I drive with an amber warning light on?
Usually yes, carefully and for a short time, but book a check soon. If the light starts flashing or the car behaves differently, stop and get help.
Why did a warning light come on and then go off?
The car may have detected a short-lived fault. The code is often still stored in the system, so a diagnostic check can show what happened.
How do I find a car repair near me for a red warning light?
Do not drive on with a red light. Enter your registration and postcode for a fixed price, then choose a mobile mechanic who comes to you, or free collection and return.
Will a warning light affect my MOT?
Some can. Lights such as engine management, ABS, airbag and brake system are checked, and a warning light that is on for these can lead to a fail.
Enter your registration and postcode for a fixed price, with parts and labour included.