Dashboard warning lights: What do they mean?
Published on 29th February 2016 in Servicing
There are 60+ warning lights on cars, all of which are crucial for flagging up mechanical malfunctions. The sooner these sensory lights flash on, the sooner you can visit an IMI-Registered Technician - and hopefully pre-empt the need for expensive fault-fixing. We’ve put together a list of the most common dashboard warning lights you’re likely to encounter, so you’ll know what they mean - and what you need to look out for.
Oil Level/Pressure Warning Light
There’s no wish-granting genie in this lamp; just a not-to-be-ignored alert that your oil level pressure is low. Ensure you turn off the engine when checking the oil level, and top up accordingly to avoid severe engine damage. If the warning light is still glowing after filling the oil to maximum capacity, alert your local IMI Registered Technician without hesitation. Whilst usually red, some cars flash up an amber version of this sign to warn drivers that the oil level is getting low, but not critically so.
Battery Charge Warning Light
What looks like a simple piece of Lego is a crucial call-to-action sign that the battery isn’t working correctly, the alternator is malfunctioning, or the car's charging system is short of power. While you do not need to stop the car as soon as this alert flashes on your dash, be aware that your drive time will be limited; typically around 30 minutes during the day and even less at night. In that timeframe, don’t put any additional electrical strain on the battery; switch off your stereo, phone charger, A/C, sat nav and other non-essentials. As soon as you are able, seek out guidance from a technical expert listed on the IMI Professional Register.
Brake System Warning Light
Unless you have forgotten to release your parking brake, this signals one of several things: there’s a too-low level of fluid in the master brake cylinder reservoir, the brake system has a potentially serious hydraulic problem, or the parking brake sensor is out of alignment. If the light remains illuminated after replenishing the brake fluid and testing the brakes by pressing on the pedal, your car is unsafe to drive. Seek the immediate help of a skilled IMI Registered Technician who will inspect the brake system for leaks, worn linings or general failure.
Engine Warning/Management Light
Also known on some vehicles as the Malfunction Indicator Lamp (MIL), this yellow submarine-looking symbol indicates that a running or emission fault has occurred: usually a loose, faulty or missing petrol cap, failure of oxygen sensor, mass airflow sensor or catalytic converter, worn spark plugs or wires, or a problem with the emissions control system. But unless your car is smoking or stalls completely, it does not require urgent attention and will be perfectly safe to drive until you have time to visit a technician and have them run a diagnostic.
Anti-lock Breaking System (ABS) Warning Light
This warning light signals that your ABS system has given up. In most cases, as soon as this warning light flashes on the dashboard, the ABS is temporarily disabled. While still safe to drive, your vehicle will not benefit from anti-lock brakes when making emergency stops or braking on wet or slippery surfaces - you will only have conventional, unassisted breaking. In the first instance, consult your owner’s manual for troubleshooting tips. If the light remains on, the ABS will need testing by an IMI Registered Technician.
Airbag Warning Light
Also referred to as the SRS light (Supplemental Restraint Systems), this car dashboard warning light flashes on for two reasons; there’s a fault with the airbag sensor itself or a problem with any one of the airbags that would activate instantaneously in the event of a side impact, frontal or near-frontal collision. While the vehicle is still safe to drive, be aware that so long as the warning light is on, the airbags will not deploy in the case of an accident. To avoid putting yourself - and passengers - at risk, seek help from your local IMI Registered Professional at the earliest opportunity.
Power Steering (EPAS) Warning Light
Also known as the Electric Power Assisted Steering (EPAS) light, what is characterised by a steering wheel and exclamation mark alerts the driver to a steering problem; either the steering fluid levels are low or there is a system fault. This may already be noticeable by way of heavy steering; annoying at low speeds but fatal at high speeds. If the light remains on after topping up the power steering reservoir with fluid (full details in your manual), you will still have control of the vehicle but may experience unintended veering even when you exert a huge amount of physical effort to turn the wheel. In all cases, cautiously move off the road and seek prompt mechanical assistance.
Temperature/Coolant Warning Light
What resembles a pirate ship is one of the most crucial of your 60+ car dashboard warning lights. Not only does it mean that the coolant levels are running low, but it also indicates that your car’s engine is rapidly overheating. In all cases, stop the car immediately but resist the urge to open the bonnet for at least 20 to 30 minutes before topping up the coolant to avoid scalding by superheated steam. If the light continues to flash red thereafter refer to the emergency steps for engine overheating scenarios in your owner’s manual. If nothing is working, seek expert technical assistance immediately.
Tyre Pressure Monitoring System (TPMS) Light
If you inflate your tyres to the correct pressure level once a month, you won’t be familiar with this odd-looking yellow cutaway tyre with an exclamation mark. It is designed to alert drivers that at least one of their four tyres is under-inflated - usually by 25% lower that what the car manufacturer recommends. While some TPMS systems indicate tyre pressures for individual wheels, many drivers will need to check the pressure of each one to ensure it matches the car’s handling capacity. Although this is one of the warning lights on cars that is more a precaution than a sign of immediate danger, it will need your attention.
Catalytic Converter Warning Light
What looks like a steaming hotpot is one of the car dashboard warning lights most likely to stump British motorists – 95% could not recognise the tell-tale sign for a malfunctioning or completely damaged catalytic converter. Prior to this light flashing on your dashboard, you would have noticed a significant decrease in your MPG - or clocked that your car goes no faster even when you’ve floored the accelerator. In all cases of a failing catalytic convertor, your car will be releasing toxic fumes all over the place before eventually packing up completely. Unfortunately there is no DIY quick-fix, so contact your local IMI-registered technician straight away.
- Dashboard survey by Britannia Rescue (July 2013)
- AA-Populus survey (September 2015)