Why, yes, it does emit a radio frequency in response to the polling of the car’s immobilizer system. You ask the car to start by pressing a button the immobilizer system wants to see some credentials and sends out a summons to the key fob. The key fob responds. There seem to be a range of frequencies used by key fobs, including 315 MHz, 418 MHz, and 433 MHz.
Linx technologies manufactures OEM-compatible aftermarket transmitters and receivers. You might consider contacting them or someone like them for advice.
LINX TECHNOLOGIES, INC.
159 ORT LANE
MERLIN, OR 97532
PHONE: (541) 471-6256
FAX: (541) 471-6251
www.linxtechnologies.com