01. Preparing the car key fob
a. Remove the factory key fob cover and the circuit board. Remove the battery.
b. Identify the contact pads of the buttons. On each button, one pin is the common pin (often "-"), and the other is the signal pin.
c. Determine the polarity of the key fob battery holder: “+” and “-”.
02. Connecting the cable wires to the key fob
Under the Keynex K1 device cover is a connector for a 10-pin ribbon cable. The wires are assigned as follows:
WARNING: The Keynex K1 device must be protected by an external fuse rated no greater than 1A on the positive DC supply line (+V). Install the fuse holder as close to the power source. Use wiring and fuse holder rated for the circuit (temperature, voltage). Replace only with the same type and rating (≤1 A).
Soldering: Solder one "button" wire only to the button's signal leg. The button's common/negative leg usually doesn't need to be connected—the common "-" is supplied through the black wire. After soldering, secure and insulate the connections.
Create a "wire → button function" mapping table (e.g., "green — open trunk"). This information will be needed when setting up the app.
03. Installing the key fob into the housing
Place the key fob board into the Keynex K1 device housing using the template. Connect the 10-pin connector to the socket on the device board, neatly arrange the wires without kinks, and replace the cover.
04. Power connection
Connect a 5-24V DC power supply: red for "+" and black for "-." A constant power source that is not disconnected when the system is armed is recommended. Then connect the cable to the USB-C port on the device.
05. Mounting the device in the car
Securely mount the device in the vehicle, avoiding areas prone to water damage or overheating. Avoid vibrations and impacts while driving.
06. Initial launch and configuration in the application
a. Power on the device and wait for it to boot up.
b. Open the mobile app and connect to the device.
c. Assign each key fob function to the corresponding wire in the cable.
d. Test each button press from the app (short presses).
07. Checking the correct soldering and automatic pinout adjustment
To ensure that the wire is not shorted to the button housing (soldering is done correctly), do the following:
a. Power the key fob board separately with approximately 3 V (instead of the battery).
b. Power the device (5–24 V). The +/- pinout for the key fob will be configured automatically.
c. Test the button presses in the app.
d. If the button does not work correctly, double-click the button on the device board to change the pinout, then test again.
e. Press all the functions and verify the car responds correctly.
Note: The key fob is powered by the device. For standalone testing, use a 3 V laboratory power source or a battery equivalent with a current limitation. Avoid reverse polarity.