Car Warning Lights Explained: What They Mean and When to Act
Modern cars have dozens of warning lights, each designed to alert you to specific issues. Some demand immediate action; others are informational. Knowing the difference can save your engine – or prevent an unnecessary panic.
Red Lights: Stop and Check Immediately
Red warning lights indicate potentially serious problems. Don't ignore them.
🔴 Engine Temperature (Thermometer in Water)
What it means: Your engine is overheating.
What to do: Stop safely as soon as possible. Turn off the engine. Do not open the bonnet immediately – wait for it to cool. Do not attempt to drive – you risk serious and expensive engine damage.
🔴 Oil Pressure (Oil Can)
What it means: Low oil pressure – the engine isn't being lubricated properly.
What to do: Stop immediately when safe. Check oil level. If level is fine but light stays on, do not drive – have the car recovered. Running an engine without oil pressure causes catastrophic damage within minutes.
🔴 Battery/Charging (Battery Symbol)
What it means: The charging system isn't working – typically alternator failure.
What to do: Turn off non-essential electrical items to conserve battery. Get to a garage soon – you have limited driving time before the battery dies completely.
🔴 Brake Warning (Circle with "!")
What it means: Could be handbrake on, low brake fluid, or a brake system fault.
What to do: First check handbrake is fully released. If light stays on, check brake fluid level. If neither resolves it, get the brakes checked immediately – do not drive if brakes feel abnormal.
Amber Lights: Attention Needed Soon
Amber lights indicate issues that need attention but aren't immediately critical.
🟡 Engine Management (Engine Outline)
What it means: Something in the engine or emissions system needs attention.
What to do: Not usually immediately urgent, but get it diagnosed soon. Continuing to drive can worsen the underlying problem and lead to MOT failure. We offer diagnostic services to identify the fault.
🟡 TPMS – Tyre Pressure (Exclamation in Tyre Cross-Section)
What it means: One or more tyres has low pressure.
What to do: Check and inflate tyres to the correct pressure (usually shown on a sticker inside the door jamb). If it comes back on, you may have a slow puncture – get it checked.
🟡 ABS Warning (ABS in Circle)
What it means: Fault in the anti-lock braking system.
What to do: Normal brakes should still work, but ABS won't activate in emergency stops. Get checked reasonably soon – this will also fail an MOT.
🟡 Airbag/SRS (Person with Airbag)
What it means: Fault in the supplementary restraint system.
What to do: Airbags may not deploy in a crash. Get diagnosed and repaired – this is a safety-critical system and will fail an MOT.
🟡 Service Due (Spanner or "SERVICE")
What it means: Scheduled service is due based on mileage or time.
What to do: Book a service when convenient. Not urgent, but don't ignore indefinitely – regular servicing protects your car's reliability and value.
What to Do When a Warning Light Appears
- Red light: Stop safely as soon as possible and investigate
- Amber light: Note it and get the car checked within a few days
- Flashing light: Usually more urgent than a steady light – treat as red
Diagnostic Services at Redline Tyres
We offer diagnostic services to read fault codes and identify what's actually wrong. Often the underlying issue is simpler (and cheaper) than you fear. Our equipment can read codes from most makes and models, and we'll explain what we find in plain English.
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