What this fob type means in practice
The Proximity Smart Key appears across 736 model-year pages in our directory, spanning 14 manufacturers. Push-button start with passive entry. The fob exchanges a continuous low-frequency challenge with the vehicle and unlocks doors as you approach. Programming almost always requires a scan tool with the vehicle's security PIN.
Programming difficulty
Proximity smart keys are the hardest fob form factor to program at home. The fob, immobilizer, and body control module exchange a continuous low-frequency cryptographic challenge that pairs require reading the vehicle's PIN or security seed over OBD-II — a procedure that almost always demands a licensed scan tool. Onboard ignition-cycle procedures do not work for proximity smart keys, regardless of what a YouTube video may claim.
What you'll spend
Aftermarket proximity fobs typically run $45–$120; OEM units from a dealer cost $220–$420 for the same hardware. Programming labor runs $80–$220 from a mobile automotive locksmith depending on your vehicle and region; dealer programming is roughly double. Owning a programmer (e.g. Autel IM608 Pro or AutoProPAD G2) only makes financial sense if you'll pair more than a handful of vehicles a year.
Common chip families
Proximity smart keys typically use one of the AES-128 chip families: NXP PCF7945 / PCF7952 / PCF7953 (Hitag-PRO), or Texas Instruments DST-AES. The chip family determines which aftermarket programmers can handle pairing — cross-reference your specific vehicle's per-year page for the exact compatibility table.
Vehicles using this fob type
Below is a sample of vehicles in our directory equipped with the Proximity Smart Key. Click into any model-year page for the full part numbers, FCC IDs, and programmer compatibility table.