Key assembly

Use the original car key to disassemble it and remove the circuit board inside, then weld it with the device.

Using the original car key, disassemble it to extract the circuit board inside and then weld it to the device. The buttons (micro-switches) on the original car key and the wiring provided by the device should be soldered one by one according to the definitions, with attention to not using too high of a temperature for the soldering gun; the buttons only need to be soldered in a diagonal pattern.

Alternatively, you can test the solder joints on the buttons with a multimeter. Set the multimeter to the continuity testing mode. Connect the two ends that should not conduct electricity (infinite resistance) to the device's wiring, paying attention to the color definitions of the wiring and ensuring that they correspond to the functions of the remote key buttons.