Modern cars have dozens of dashboard warning lights, and knowing which ones need immediate attention and which can wait is essential for keeping your car safe and avoiding expensive damage.
The Colour Code
Dashboard warning lights follow a simple traffic-light system:
- Red — Serious. Stop driving as soon as it's safe to do so.
- Amber/Yellow — Caution. Something needs attention, but you can usually continue driving to a garage.
- Green/Blue/White — Information only. The system is on or working normally.
Critical Red Warnings
Engine Temperature
The thermometer-in-water symbol means your engine is overheating. Stop immediately when safe. Continuing to drive can cause catastrophic engine damage including warped cylinder heads or a blown head gasket, costing thousands to repair. Common causes include low coolant, a failed water pump or a stuck thermostat.
Oil Pressure
The oil can symbol means oil pressure has dropped dangerously low. Stop the engine immediately. Running without oil pressure will destroy the engine within minutes. Check the oil level using the dipstick — if it's low, top up before restarting. If the light stays on with correct oil level, do not drive — call for recovery.
Brake System
The exclamation mark in a circle means a brake fault has been detected. Check whether the handbrake is fully released first. If it is and the light persists, brake fluid may be low or there could be a hydraulic failure. Drive slowly and carefully to the nearest garage.
Battery/Charging
The battery symbol means the charging system isn't working properly. Your car is running on battery power alone and will eventually stop. Drive directly to a garage or safe location — you may have 20–30 minutes before the battery dies.
Common Amber Warnings
Engine Management Light (EML)
The most common amber light. It can indicate anything from a loose fuel cap to a failing catalytic converter. A steady amber EML means book a diagnostic soon. A flashing EML means a misfire is occurring — reduce speed and get it checked urgently to avoid catalytic converter damage.
MOT note: A lit engine management light is an automatic MOT failure.
Tyre Pressure (TPMS)
The exclamation mark inside a tyre cross-section means one or more tyres are significantly under-inflated. Check and adjust all tyre pressures at the nearest petrol station. If a tyre keeps losing pressure, it may have a slow puncture.
ABS Warning
The "ABS" text in a circle means the anti-lock braking system has a fault. Your normal brakes still work, but the ABS safety feature won't activate in an emergency stop. Get it checked soon.
Check Your Car's Health
Many warning light issues will show up in your MOT history as advisories or failures. Reviewing past MOT results can help you understand recurring problems with your specific car.