TannadiceMotors
Warning lights
What the common lights mean, how urgent they are, and what to do next — in plain English.
Red — stop when it’s safe and call us.
Amber — get it checked soon.
What it means: The engine’s computer has logged a fault — anything from a loose sensor to a misfire.
What to do: If it’s steady, the car is usually safe to drive gently to us for a diagnostic check. If it’s flashing, ease off and get it looked at straight away: a misfire can damage the catalytic converter.
An engine management light that stays on is an MOT fail.
What it means: The anti-lock braking system has a fault. Your normal brakes still work, but the wheels can lock under hard braking.
What to do: Drive carefully, leave extra stopping distance and book a check. Common causes are wheel speed sensors and wiring.
An ABS warning light indicating a fault is an MOT fail.
What it means: Oil pressure is too low to protect the engine.
What to do: Stop as soon as it’s safe and switch the engine off. Check the oil level once it has cooled. Don’t keep driving — call us.
What it means: The charging system isn’t working, so the car is running on what’s left in the battery. Often the alternator or its drive belt.
What to do: Switch off anything you don’t need and head for the garage. Avoid stopping the engine somewhere you can’t get help.
What it means: One or more tyres is low, or the tyre pressure monitoring system has a fault.
What to do: Check and adjust all four pressures (the right figures are usually inside the fuel flap or door pillar). If it comes back, you may have a slow puncture.
On cars first used from 2012, a faulty tyre pressure monitoring system is an MOT fail.
What it means: The handbrake is on, the brake fluid is low, or there’s a fault in the braking system.
What to do: Check the handbrake is fully off. If the light stays on, don’t drive — low fluid can mean a leak. Call us.
What it means: The diesel particulate filter is getting blocked with soot, which is common on diesels that do mostly short trips.
What to do: Your handbook will say how to let it clean itself — usually a steady drive at higher speed. If the light stays on, bring it in before it becomes a bigger repair.
What it means: There’s a fault in the airbag or seatbelt tensioner system, so they might not work in a crash.
What to do: The car will drive normally, but get it checked soon.
An airbag warning light showing a fault is an MOT fail.
This is general guidance. Symbols and colours vary between manufacturers — your handbook has the final word. If in doubt, don’t drive it: call 01382 690898.
Light still on?