Five Car Warning Lights You Shouldn't Ignore

In a recent study, Carly uncovered a startling fact: more than a third of vehicles on the road, 35%, have serious faults that could jeopardise the safety of drivers and passengers. This study, based on 6.8 million diagnostics in 2024, highlights a clear need for drivers to have access to critical information about their vehicles before these faults escalate into emergencies.

To help drivers avoid mechanical issues that could lead to costly repairs or accidents, there are five key warnings every driver should know, but few truly understand. It's possible to anticipate critical vehicle failures up to 42 days before they manifest, allowing for early intervention that prevents severe damage and maintains road safety.

First is the oil pressure indicator. Did you know that dashboard lights have different meanings depending on their colour and whether they flash or remain steady? In many cars, a yellow (sometimes grey) oil pressure light indicates low oil levels, while a red light can range from a simple service alert to a total loss of oil pressure. Carly warns: if this light is red and steady, stop the engine immediately! Driving without oil pressure could severely damage the engine.

The "red" generator light is not just about the battery. The red generator light indicates a failure in the charging system, not the battery itself, and many drivers mistakenly believe they can continue driving. However, doing so could cause a failure of safety and assistance systems. If you see this light, stop in a safe place as soon as possible and turn off the car.

The engine control light (MIL) can remain steady or flash, and many ignore the difference. A steady yellow light usually indicates an emissions failure, while a flashing light means emergency mode has been activated. In both cases, Carly recommends finding a safe place to park and consulting the vehicle manual to understand which system is affected.

There's also the immobiliser light (WFS). If your engine won't start and you see a light showing a car and key symbol, this is the reason. This light, also known as the immobiliser light, indicates a security system issue preventing the engine from starting. If you see this light, Carly recommends trying to start with a second key or, in an emergency, consulting the Carly app to check the immobiliser status.

Similarly, the tyre pressure warning light. Many drivers worry unnecessarily when they see this light after a tyre change, often because they forgot to reset the pressure sensor. However, Carly warns that this light can be critical if there's a genuine pressure loss or the sensor is failing. Ignoring the light could lead to uneven tyre wear and increase the risk of accidents.