Problem:
Attempted to do all keys lost on a 2025 Hyundai Sonata with Autel IM608 and Smart Pro too. Already prepurchased the PIN code. Autel couldn’t communicate with the ECU. And the smart pro would display me this unknown error. Any solution?
Here is the clue:
The car’s ECU is locked out.
Leave car alone for a few hours (or 24 hours), the ECU will unlock and try again. Make sure the battery is fully charge.
Sometimes disconnecting the battery and shorting the cables out and reconnecting but don’t touch anything for about 5 minutes will bring back communication to program the key, just don’t plug in your tool right away.
You can program with the autel under a different application. Go under diagnostic side.
Some others had the same issue with IM608 & SmartPro. Finnaly OBDStar G3 woke ECU and programmed key with dealer pin no problems. OBDSTAR is go to for newer hyundai/Kia, reads most pincodes as well.
