Modern cars have more than fifty possible warning symbols, and almost none of them are explained on the dashboard itself. The good news is that the colour tells you most of what you need to know before you have identified the symbol at all.
What the Colours Mean
| Red | Stop as soon as it is safe. Red means a fault that can hurt you or wreck the car quickly — oil pressure, brakes, charging failure, overheating, airbags. Driving on is a gamble with the engine or your safety. |
|---|---|
| Amber / Yellow | Investigate soon, but you are not stranded. Something has failed a self-test. The car will usually still drive, often with reduced power, and the fault should be read with a scanner within a few days. |
| Green / Blue | Information only. A system is switched on — lights, cruise control, indicators. Nothing is wrong. |
A red oil pressure light and a red temperature warning can destroy an engine within minutes of coming on. Pull over safely, switch off, and do not restart to “just get home”. A tow is far cheaper than an engine.
Common Warning Lights
Latest Warning Light Guides
All warning light guides ›-
Check Engine Light Comes On Only When It Rains
An environmental trigger this specific is a genuine diagnostic gift — it points almost directly at moisture intrusion in the ignition system.
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Check Engine Light Came On After an Oil Change
A check engine light appearing right after an oil change is rarely a coincidence — something the service touched is almost always…
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Maintenance Required Light On: What It Means
This light has nothing to do with a detected fault — it’s a scheduled reminder based purely on mileage or time, and…
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Security or Anti-Theft Light Flashing, Car Won’t Start
This is one no-start cause that has nothing mechanical wrong with it at all — the immobilizer is simply refusing to recognize…
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Brake Pad Wear Warning Light On (Electronic Sensor)
This dashboard light comes from a physical wire embedded in the pad, not the mechanical squealer tab — and that wire can…
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Parking Brake Warning Light Stays On: Causes
This light usually means exactly what it looks like — the parking brake isn’t fully released — rather than a hydraulic brake…
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Check Engine Light Flickers On and Off Intermittently
A light that comes and goes over days is a different symptom from one that flashes rapidly while driving — and it…
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Seatbelt Warning Chime Won’t Stop: Causes
A persistent seatbelt chime with the belt actually buckled almost always traces to the seat’s weight sensor or the buckle switch itself,…
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Door Ajar Warning Light Won’t Turn Off
A door ajar light that won’t clear, even with every door confirmed shut, usually traces to one specific door’s sensor rather than…
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Washer Fluid Warning Light Stays On: Causes
This is one of the least urgent warning lights on the dashboard, but a light that won’t clear even after refilling usually…
Why Clearing the Light Is Not a Fix
Disconnecting the battery or clearing codes with a scanner turns the lamp off. It does not repair anything, and it has two real costs:
- You lose the evidence. Freeze-frame data and pending codes are the most useful diagnostic information the car has, and clearing wipes them.
- Emissions readiness resets. After a clear, the car needs a full drive cycle before its self-tests report as complete — and it will fail an emissions or MOT-style test until they do.