Which car warning lights mean stop, and which can wait

Dashboard lights look alarming because they arrive without explanation. They are grouped by colour, and the colour tells you what to do next. Knowing the three groups lets you react calmly instead of panicking.

Red means stop safely, now

Red lights warn of a problem that can damage the car or cause a crash. Oil pressure and coolant temperature are the two that matter most. If either comes on, pull over where it is safe, switch off the engine and check the handbook. Driving on with low oil pressure or an overheating engine can turn a cheap repair into an engine replacement.

A red brake warning light usually means the parking brake is engaged or the fluid level is low. Either way it is worth stopping to check.

Amber means check it soon

• Engine management light: steady usually means a fault to have read soon; flashing calls for reduced speed and a stop.
• Tyre pressure: check pressures when the tyres are cold and top up to the figures on the door pillar.
• ABS or traction: normal braking still works, but grip on a wet road is limited, so slow down.
• Glow plug or exhaust filter: these often clear after a longer run at a steady speed.

Green and blue are information

Green or blue lights usually tell you a system is switched on, such as headlights, indicators or cruise control. A blue main-beam light is a reminder to dip for oncoming traffic, not a fault.

What to do before anything goes wrong

Read your handbook once and note what each symbol means for your car, because the same shape can mean different things across models. Check tyre pressures monthly when the tyres are cold, and check oil and coolant levels on a flat surface. If you are unsure what a light wants, treat it as a reason to stop at the next safe place rather than to keep driving. Road safety research bodies such as iihs.org publish general vehicle safety guidance, and India's road transport ministry publishes rules at morth.nic.in.

The bottom line: red means stop, amber means book a check, and green or blue usually just means the system is on.