How to Solve Lonsdor K518 MQB49 5C 5D Data Reading Failed Error 25?

Problem:

Trying to make a key for a 2019 VW Polo, Normal key not proximity. 5c chip. I tried using both adapters that are in the shape of the key. Lonsdor K518 failed to read original key data with the MQB49 5C adapter.

It reported an error “Data reading failed. Error code Unlock failed ret=25”. Any solution?

Solution:

Check the connection diagram carefully. You need to solder one wire from the key circuit board to the 5C interface board, as shown in the diagram. Then try again, and it should work.

Not for all key types. For this type key, solder 1 wire to the board.

If reading the original key data for BMW BDC2 or BDC3 fails, try the same method.