Gather Required Materials

• New key fob compatible with 2015 Audi A4
• Existing programmed key
• Vehicle owner's manual
• VCDS (VAG-COM Diagnostic System) or a similar tool (optional)

Determine the Type of Key You Have

• There are various types of Audi key fobs. Confirm that your new key fob is compatible with your 2015 Audi A4.

Access the Vehicle

• Enter your Audi A4 using the already programmed key fob.
• Make sure all doors are closed before you begin the programming process.

Insert the Existing Key

• Insert the existing, already programmed key into the ignition.
• Turn the ignition to the "ON" position without starting the engine.

Program the New Key Fob

• Using the VCDS tool, connect to your vehicle's OBD-II port.
• Navigate to the “Adaptation” or “Immobilizer” section of the system.
• Follow the instructions to enter a new key. This usually involves entering a security code (often referred to as the "PIN" or "SKC").
• After entering the required information, press the button on the new key fob. You may need to hold it for a few seconds to complete the process.

Test the New Key Fob

• Turn off the ignition and remove the existing key.
• Insert the new key fob into the ignition and turn it to the "ON" position.
• Verify that the new key fob is able to start the engine and lock/unlock the doors.

Repeat If Necessary

• If you have more than one new key fob to program, repeat the steps for each additional key.

Professional Help

• If you encounter any issues or if the VCDS tool is not available, consider taking the car to an Audi dealership or certified locksmith specializing in Audi vehicles.