A car-and-key or padlock symbol relates to the immobiliser. Why it flashes when parked, and what it means if the car will not start.
Looking for more detail? Our full guide covers this topic in depth, with step-by-step advice and sources.
A flashing light when parked is usually the alarm or immobiliser showing it is armed. A light at start-up that stays on means the car has not recognised the key.
What it looks like
A car outline with a key or padlock. Colour: Red, green or amber depending on maker.
Common causes
- Flat battery in the key fob
- Using a spare key that is not programmed
- Immobiliser or transponder fault
What to do
- Try the spare key.
- Replace the key fob battery (often a CR2032 coin cell, but check).
- Many keyless cars let you start the car by holding the key against a marked spot on the steering column or start button: see your handbook.
Can I keep driving?
If the car starts and runs, yes.
MOT
No.
Symbols vary slightly between makes. Always check your owner's handbook. General guidance only; if in doubt, call your breakdown provider.
Sources and further reading
Facts checked on 20 October 2026. Spotted an error? Tell us and we will correct it.