Xhorse XT15 Chip is not a super chip but a specific chip for BMW PCF7935. Here is a successful test of adding keys for a Mini Cooper R56.

EWS3+ module.

Read data with AK90+.

Write data to XT15 Transponder with Key Tool Plus Pad.
Generate remote with VVDI Mini.

Keys work in the door, work perfectly.

Credit to Hassan Mohamed
Skype: xhorsevvdi.com
Whatsapp: https://wa.me/8613983756354

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