Warning light guide
Something lit up on your dashboard? Tap the light that matches to see what it means and whether it’s safe to keep driving.
Choose a warning light
Select a light to see what it means and what to do next.
Engine management
What it means
The engine control unit has detected a fault. It could be anything from a loose fuel cap or sensor to a misfire. If it flashes, the engine may be misfiring badly enough to damage the catalytic converter.
What to do
Steady: book a diagnostic check soon. Flashing: reduce speed, avoid hard acceleration and get it checked as soon as possible.
Oil pressure
What it means
Oil pressure has dropped too low to protect the engine. This can be low oil level or an oil pump problem, and running the engine like this can cause serious damage quickly.
What to do
Stop as soon as it is safe, switch off the engine and check the oil level. Do not keep driving if the light stays on. Call us for advice.
Battery / charging
What it means
The car is not charging its battery properly, usually an alternator or drive belt fault. The car will run on battery power alone until it goes flat and stops.
What to do
Turn off non-essential electrics (heater, radio), get somewhere safe and have it checked. Avoid switching off if you need to get home, as it may not restart.
Coolant temperature
What it means
The engine is overheating. Common causes are low coolant, a leak, a failed fan or thermostat. Continuing to drive can damage the head gasket.
What to do
Stop safely and switch off the engine. Let it cool fully before checking the coolant level. Never open the coolant cap when the engine is hot.
Brake system
What it means
Either the handbrake is on, the brake fluid level is low, or there is a fault in the braking system.
What to do
Check the handbrake is fully released. If the light stays on, do not drive the car. Brakes are safety critical, so call us.
ABS
What it means
A fault with the anti-lock braking system. Your normal brakes still work, but the wheels could lock under heavy braking.
What to do
Drive carefully, leave extra stopping distance and book a diagnostic check. If the red brake light is on as well, stop driving.
Airbag (SRS)
What it means
There is a fault in the airbag or seatbelt pretensioner system, which means the airbags may not deploy in a crash.
What to do
The car can be driven but you are not fully protected. Book a diagnostic check promptly. An SRS warning light is also an MOT failure.
Tyre pressure (TPMS)
What it means
One or more tyres are below the correct pressure, or you may have a slow puncture.
What to do
Check and inflate all tyres to the pressures in your handbook (often inside the fuel flap or door), then reset the system. If it keeps coming back, have the tyre checked.
Glow plug (diesel)
What it means
On diesels, this light normally comes on briefly while the glow plugs warm the engine before starting. If it flashes or stays on while driving, there is an engine or glow plug fault.
What to do
Wait for it to go out before starting. If it flashes or stays on, book a diagnostic check.
Diesel particulate filter
What it means
The diesel particulate filter is getting blocked with soot, common on cars that do lots of short journeys.
What to do
A steady 20 minute drive at motorway or dual carriageway speed often lets it clean itself. If the light stays on after that, book in before it needs a costly replacement.
Power steering
What it means
A fault with the electric power steering. The steering may feel very heavy, especially at low speeds.
What to do
Drive carefully, take extra care when parking and book a check. If the steering becomes very heavy, stop when safe and call us.
Traction / stability control
What it means
Flashing means the system is working to stop wheelspin on a slippery road. Staying on means it has been switched off or there is a fault.
What to do
Flashing: ease off the accelerator. Staying on: check it hasn't been turned off by the button, otherwise book a diagnostic check.
This guide is general advice only. Symbols vary between manufacturers, so always check your vehicle handbook. If in doubt, stop safely and call us on 07702 341414.
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