Warning lights follow a simple traffic-light logic. Red: a serious problem or a safety risk, so stop as soon as it's safe. Amber or yellow: something needs attention soon, so drive gently and get it checked. Green or blue: information only (lights on, cruise control active). Symbols vary slightly between makes, so your owner's manual is the final word, but the ones below are nearly universal.
You'll need
- Your owner's manual (the warning-light pages)
Step by step
- 1
Oil pressure — red oil can: stop now
The engine has lost oil pressure. Pull over safely and switch off immediately; driving on can wreck the engine within minutes. Check the oil level once it has settled. If the level is fine and the light stays on, don't drive — get it towed or inspected.
- 2
Engine temperature — red thermometer: stop now
The engine is overheating. Pull over safely and switch off. Don't open the coolant cap while it's hot. Once it's fully cold, check the coolant level and look for leaks. Repeated overheating can warp the cylinder head.
- 3
Battery / charging — red battery: head somewhere safe
The charging system (usually the alternator or its drive belt) isn't charging the battery. The car is now running on battery alone and will die once it's flat, often within 20–60 minutes. Switch off non-essentials (aircon, radio, heated seats) and head straight to a safe place or a mechanic. Don't switch off in the middle of nowhere — it may not restart.
- 4
Brake system — red (!) in a circle: check, and don't drive if unsure
First make sure the handbrake is fully released. If the light stays on, the brake-fluid level may be low or there may be a fault in the brake system. If the pedal feels soft or travels further than usual, stop and don't drive.
- 5
Airbag / SRS — red figure with a circle: get it checked
A fault in the airbag or seatbelt-tensioner system, which means the airbags may not deploy in a crash. The car still drives normally, but have it checked soon.
- 6
Check engine — amber engine outline: check soon (or now if flashing)
Steady: the engine computer has logged a fault. It could be minor (a loose fuel cap) or serious, so get the code read soon — you can look up what it means with our free fault-code tool. Flashing: a severe misfire. Ease off, avoid hard acceleration, and get it seen promptly, because unburnt fuel can overheat and destroy the catalytic converter.
- 7
ABS — amber 'ABS': normal brakes, no anti-lock
Your normal brakes still work, but the anti-lock system won't help in an emergency stop, especially on wet roads. Leave extra following distance and get it checked.
- 8
Tyre pressure (TPMS) — amber horseshoe with (!): check your tyres
One or more tyres is under-inflated. Slow down and check the pressures at the next safe opportunity. If a tyre is visibly flat, stop and change the wheel.
- 9
Traction / stability control — amber car with skid lines
Flashing briefly while driving means the system is working to stop a skid, so ease off. Staying on means the system is switched off or faulty; drive gently, especially in the wet.
Pro tips
- At start-up most lights come on briefly as a bulb check. That's normal; what matters is whether they go out once the engine is running.
- A light that comes and goes is still telling you something — note when it happens (hot engine? over bumps?) and tell your mechanic.
- Diesels also have a glow-plug light (amber coil) that should go out before you start, and some have a DPF warning; see your manual.
Stop and get a mechanic if…
- Any red warning light that stays on.
- A flashing check-engine light.
- Several warning lights come on together — often a charging-system or electrical fault.
General guidance only. Your owner's manual has the final word on specs, fluids and procedures for your vehicle. Last reviewed 24 September 2026.