For all motorists, from the newly-qualified and young drivers we look after here at Carrot right up to experienced pros with decades behind the wheel, seeing a dashboard warning light illuminate can bring on that sinking feeling.
The AA attends almost 20,000 dashboard warning light-related call-outs each month with annual peaks in March and September after people have picked up their brand new cars, like the 17-plate models coming out next month.
After surveying their breakdown members, it was found that blokes are more likely to hope that turning their car off, reading the hand book and then switching the ignition back on again will fix an issue and get rid of the warning light. Female drivers are more likely to safely stop and phone someone they trust for advice.
Another breakdown provider, Green Flag, carried out a survey last summer and learned that UK drivers typically spend another 71 hours (obviously not continuously) behind the wheels of their cars before getting warning light problems looked into by a garage.
They reckon a big factor behind motorists like these causing more damage to their cars by delaying doing anything about warning lights is because almost 25% of people didn’t know, for example, what the low tyre pressure warning symbol meant and a fifth didn’t recognise the often serious red engine warning light. Drivers aged 18-34 had the poorest knowledge of dashboard warning lights according to the survey.
Most cars made during the last twenty years or so incorporate engine management systems or electronic control units (ECU), which receive information from sensors all around the car. As soon as they detect that something isn’t right, from a tiny bulb that’s blown, right up to an engine that’s about to blow, they tell the ECU, which then displays a warning light on the dashboard. Simples.
The general rule is:
Blue or green lights tell you that something is switched on, such as your headlights, but there’s nothing to worry about
Yellow or orange lights tell you that a problem has been detected, such as one of your tyres has dropped below the recommended pressure, and that you should get a garage or someone competent to look at it as a priority – but you don’t necessarily need to stop on the hard shoulder or anything
Red lights are much more serious and shouldn’t be ignored. If a red light illuminates and stays lit on your dashboard, it’s recommended that you bring your car to a stop ASAP, somewhere safe.
Building up a pretty good understanding of warning symbols in advance can help reduce any possible worry, especially for drivers with less experience, which is what this blog’s all about. We know that most of our customers can’t afford expensive cars with loads of gadgets, and that few of you drive hybrids, 4x4s or automatics, so we’ve stuck to lights you’re more likely to see.
It’s normal for most or all of a car’s warning lights to illuminate when the ignition is first turned on, but they should disappear a few seconds afterwards. Although the symbols may differ slightly depending on the make and model of car you’re in, and they may shine red or yellow/orange according to how serious the problem is, the main dashboard warning lights to be aware of are:
Brakes e.g. fluid leaks
Engine cooling system
Parking brake (handbrake)
Engine management (including software + emissions)
Anti-lock braking system (ABS)
Tyre pressure incorrect (possible slow puncture)
Glow plugs (diesel cars)
Airbag and seatbelt system
Diesel particulate filter (DPF)
Engine oil level
Battery or charging system
Electronic stability program (ESP)
You may turn out to be one of the few really lucky motorists who never see any of these dashboard warning lights, but chances are you’ll see one or more of them from time to time – and now you know what they refer to. If it’s red, stop ASAP and seek help. If it’s yellow, don’t worry too much but get someone to look at the car as a priority. And if it’s a blue or green light, you can chillax.