What do the common warning lights mean?
These are the lights our form asks about, and what they generally mean. They’re general meanings only: your handbook explains what each light means on your car, and what to do about it.
- Engine: the DVSA’s MOT inspection manual calls this the engine malfunction indicator lamp (MIL), sometimes called the engine management light. It comes on when you switch on and then goes off (on some cars, once the engine starts). If it stays on, it’s indicating a malfunction.
- ABS: the DVSA’s driving test safety questions say the warning light should come on if there’s a fault with the anti-lock braking system.
- Tyre pressure: the tyre pressure monitoring system (TPMS). The MOT manual says the lamp stays on if the system has picked up a loss of pressure, which doesn’t automatically mean the system has a fault, and that when the system has a fault, the lamp may flash a number of times and then stay on.
- Airbag: airbags are part of what the MOT manual calls the supplementary restraint system (SRS), and its warning lamp is there to show a malfunction in that system.
- Oil: a warning about the engine oil. Your handbook explains what it means on your car.
- Battery: the Highway Code says that if the charge warning light comes on while you’re driving, it may mean that the battery isn’t charging.
Cars have other warning lights too, for example for the brake fluid, the electronic stability control (ESC), the power steering or the electronic parking brake. Tell us about any light that’s on, whether or not it’s on our list.
The Highway Code says: “Make sure that you understand the meaning of all warning displays on the vehicle instrument panel. Do not ignore warning signs, they could indicate a dangerous fault developing.”
Will a car with a warning light pass its MOT?
It depends on the light. gov.uk says a vehicle fails if the test result lists ‘dangerous’ or ‘major’ problems. The DVSA’s MOT inspection manual lists these as major problems:
- the engine malfunction indicator lamp indicating a malfunction, on petrol cars first used from 1 July 2003 and diesel cars first used from 1 July 2008
- the ABS warning device showing a system malfunction
- the airbag (SRS) warning lamp indicating a system malfunction
- the warning lamp for the electronic stability control (ESC), the electronic power steering (EPS) or an electronic parking brake indicating a malfunction
A brake fluid warning light that’s on is listed as a minor problem, and the manual says an illuminated brake wear indicator is not a reason for failure. Our page MOT advisories explained explains what advisory, minor, major and dangerous mean.
How do you price a car with a warning light on?
When a warning light is on, one of our buyers looks at the details before we give a price, and calls you within 30 minutes (9am–6pm Mon–Fri, 9am–5pm Sat); outside those hours, we call first thing the next working morning. They look at which lights are on, your other answers and the car’s MOT history, then price the car as it is. You don’t need a diagnosis first, but if you’ve had one, tell us what it found.
We only change the price if the car isn’t as you described, and we show you what and why before you decide. Our driver checks the car against your description, so tell us about every light that’s on.
What should I tell you?
The more we know, the firmer the price. On our form, answer yes to the warning lights question. Useful things to mention in the “Anything else we should know?” box:
- which lights are on, and any message on the dash
- whether a light stays on all the time or comes and goes
- when it first came on, and anything you noticed at the time, such as a noise or a smell
- anything that has already been checked or diagnosed, and any paperwork
Can I drive the car to you?
We can’t tell you whether your car is safe to drive with a warning light on. Your handbook explains what each light means and what to do. If you’re not sure, choose collection when you agree your price: we offer free collection anywhere in the UK.
Do I need to get it fixed first?
No. You don’t need to repair anything or get a diagnosis to sell to us. Tell us what’s been done and what hasn’t, and we price the car as it is.
General information only, not advice about your own situation. Your handbook explains the warning lights on your car, and the DVSA’s MOT inspection manual has the full MOT rules.