OWNER ANSWER
Why does my electric BYD ATTO 2 seem to start without the key?
Check whether the instrument cluster actually shows OK. BYD uses that indicator to show the car is ready to drive. For a normal smart-fob start, the electric ATTO 2 handbook says the registered fob must be inside the cabin.
- With the car in Park and the parking brake on, switch it off using START/STOP. Check that the OK indicator has gone out.
- Check for a spare fob in the cabin and consider whether you recently used an NFC card, a phone key or remote start. If you compare start behaviour, keep the car in Park and use a known working key as your comparison.
- For the normal fob check, bring the valid fob into the cabin, press the brake and press START/STOP. Look for OK on the cluster.
What success looks like
OK goes out when you switch off and appears when a normal fob start succeeds. BYD lists the cabin as the fob’s starting area and describes a No key detected message when the key cannot be detected.
If that did not work
If OK returns after a full shutdown when all authorised keys are accounted for and you have given no remote command, switch the car off and lock it with a working key. Tell BYD the exact entry method, the cluster messages and whether the result also happens after a normal fob entry. Ask them to check the registered keys and start authorisation. One Australian ATTO 2 owner reported different behaviour after using a card or app. The duration was unclear and may depend on the vehicle or software.
Keep the test stationary in Park. Confirm the car is off and locked before leaving it.
Useful next steps
- Read the ATTO 2 smart-fob detection area (BYD UK)
- Check the ATTO 2 OK and No key detected indicators (BYD UK)
- Check an ATTO 2 that will not unlock
BYD electric ATTO 2 RHD handbook, printed pp. 52 and 100–102. Checked 13 November 2026.
Open source (BYD UK)