Amber light
Immobiliser / Key Warning
The car does not recognise the key, or the immobiliser has a fault.
Normal risk
The engine may not start. Try the spare key before calling for help.
Short answer · Why does the key light flash and the car won't start?
The immobiliser has not recognised the key's transponder. Try the spare key; if that works, the first key's chip or battery is the problem. If neither works, the antenna ring or immobiliser unit may be faulty. A flashing key symbol with the car locked is often normal: it shows the immobiliser is armed.
What to do
- Try the spare keyRules out the key itself.
- Replace the key batteryKeyless keys need a working battery; many cars have a backup spot to hold the key.
- Call the maker's serviceKeys and immobilisers need coding tools.
How is the light behaving?
| What you see | What it usually means | What to do |
|---|---|---|
| Flashing | Immobiliser armed with the ignition off | Nothing |
| Steady | Key not recognised or immobiliser fault | Try the spare key |
Possible causes
- Key battery flatKeyless start fails.
- Damaged transponder chipThe key is not recognised.
- Antenna or control unit faultThe car cannot read any key.