Dashboard warning lights: what to do about each colour
Warning lights are colour-coded like traffic lights. Getting the colour right tells you whether to pull over or carry on to the garage.
Red — stop safely, now
Oil pressure, engine temperature, brake system and battery charge lights in red mean stop as soon as it's safe. Driving on with low oil pressure or an overheating engine can turn a £200 job into a £2,000 one.
Amber — book in soon
Engine management (the engine outline), ABS, tyre pressure, DPF and glow plug lights. The car is usually drivable but something is out of spec. A diagnostic scan costs around £40–£70 and tells you the fault code.
Diagnostics done right
A code is a clue, not a diagnosis. A good garage reads the code, tests the component and tells you the price before replacing anything. Ask for the code — it's yours.