Hyundai Smart Key gets locked once it is programmed or matched to a car. Keydiy KD-X2 remote maker can be used to unlock this key so that it can be used again with any other Hyundai i20 cars.
Hyundai i20 Smart Key Renew with Keydiy KD-X2
How to unlock/renew Hyundai i20 smart key?
i20 ID46 smart key 3-button
In keydiy KD-X2, select Chip Function->Automation detection clone->Start identifying
KD-X2 detects remote sensor is locked
Disassemble the smart key, take put key PCB and remove battery
In KD-X2, select Chip Function->Remote Renew->Hyundai KIA->V3 KeylessGo(PCF7953)
connect Keydiy kd-x2 and key PCB via remote data cable
Press UNLOCK to unlock key
Check again: Chip Function->Automation detection clone->Start identifying
Keydiy KD-X2 renew i20 smart key success.