Every Dashboard Warning Light Explained: What They Mean and What to Do
Dashboard warning lights are your car's way of communicating a problem — but with dozens of different symbols, it's not always clear how seriously to take them. Here's a comprehensive guide to the most important ones.
Red Warning Lights — Stop Driving
Red lights indicate serious problems that require immediate attention. Pull over safely as soon as possible.
Engine Oil Pressure (Oil Can Symbol)
What it means: Oil pressure has dropped dangerously low. Continuing to drive could destroy the engine.
What to do: Stop immediately. Check oil level. Do not drive until resolved — have the car recovered if necessary. Repair cost: £100-£2,000+ depending on cause.
Engine Temperature (Thermometer Symbol)
What it means: The engine is overheating. Common causes: coolant leak, failed water pump, stuck thermostat, or failed radiator fan.
What to do: Pull over, turn off the engine, wait for it to cool. Check coolant level (never open the cap when hot). Repair cost: £150-£800.
Battery/Charging System
What it means: The alternator isn't charging the battery. The car will eventually stop as the battery drains.
What to do: Turn off all non-essential electrics. Drive to the nearest garage or safe stopping point. Repair cost: £200-£600.
Brake System Warning
What it means: Could indicate low brake fluid, worn brake pads, or a brake system fault. Also illuminates when the handbrake is on.
What to do: If the handbrake is fully released and the light remains, have brakes inspected immediately. Repair cost: £100-£500.
Amber Warning Lights — Attention Needed
Amber lights indicate issues that need attention but aren't immediately dangerous. Book a service or inspection soon.
Engine Management Light (EML)
What it means: The engine control unit has detected a fault. Could be anything from a loose fuel cap to a sensor failure.
What to do: If the car drives normally, book a diagnostic check within a few days. If flashing, reduce speed and avoid hard acceleration. Diagnostic cost: £50-£100. Repair cost varies hugely.
ABS Warning Light
What it means: The anti-lock braking system has a fault. Normal brakes still work, but ABS won't activate in an emergency stop.
What to do: Drive carefully and have it checked soon. Repair cost: £100-£400.
Tyre Pressure Monitoring (TPMS)
What it means: One or more tyres has low pressure, or the TPMS sensor has failed.
What to do: Check all tyre pressures at the nearest petrol station. If a tyre is losing pressure rapidly, don't drive on it. Cost: Free (inflation) to £100+ (new sensor or tyre).
DPF Warning (Diesel Only)
What it means: The Diesel Particulate Filter is becoming blocked — usually from too many short journeys.
What to do: Take the car for a 20-30 minute motorway drive at 2,500+ RPM to trigger a regeneration cycle. If the light persists, book a diagnostic. Repair cost: £300-£2,000+.
For a complete interactive guide to warning lights, visit our Car Tips & Troubleshooting page — tap any warning light to see its meaning, urgency level, and estimated repair cost.
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