How do I know what frequency my car key is?
Typically, car key remotes transmit on a regional RF frequency: about 315 MHz in North America and about 433.92 MHz in Europe. The exact frequency depends on your vehicle’s make, model, and year, so verify with labeling on the key, the manual, or your dealer.
Why the frequency matters
Knowing the correct frequency is important for ordering a replacement key, getting a new fob programmed, or diagnosing why a key might not work when traveling or after a repair. Different regions and generations of keys use different standards, and some vehicles bundle remote access with an immobilizer system that operates on a separate frequency.
Remote signal versus the immobilizer chip
The car’s remote (lock/unlock, trunk release, and sometimes push-button start) uses a higher RF frequency to communicate with the vehicle. The key’s embedded immobilizer transponder, which verifies you have a legitimate key, relies on a low-frequency channel to wake and respond. These are separate systems and often use different frequencies. Do not confuse the two when shopping for a replacement key or getting one programmed.
How to determine your key’s frequency
Use these methods to identify the transmit frequency used by your key fob. Each approach has its own advantages and limitations.
- Check the owner's manual, vehicle documentation, or the key fob packaging for any frequency information or regulatory identifiers.
- Inspect the key fob itself for labels, a model number, or an FCC ID (or equivalent regulatory ID). If present, you can search online for that ID to confirm the frequency.
- Look up the FCC ID (or equivalent) printed on the fob. The regulatory database entry typically lists the transmit frequency and allowed bands for that device.
- Contact the car maker’s dealership or customer support with your VIN and key details. They can confirm the exact remote frequency and any required programming steps for your vehicle.
- If you have access to legitimate RF equipment (such as a handheld detector or a software-defined radio) and understand the legal constraints, you can identify the carrier frequency when you press a button on the remote. Always operate within local laws and avoid interfering with other devices.
Having the right frequency helps you obtain an exact replacement key or have a locksmith or dealer program a new fob correctly.
Common regional frequencies at a glance
Here’s a quick reference for typical remote frequencies by region. Exact values can vary by manufacturer and model, so always verify with official sources if you need an exact figure for programming.
- North America: commonly around 315 MHz for standard remote functions
- Europe and parts of Asia: commonly around 433.92 MHz
- Some newer or specialty models: may use 868 MHz or 915 MHz in certain regions
- Immobilizer transponder: typically a low-frequency channel (commonly around 125 kHz) used to power and read the chip; this is separate from the remote frequency
In practice, the exact frequency depends on your vehicle’s make, model, and year. When ordering a replacement or getting a key programmed, provide your VIN and ask the dealer or a qualified automotive locksmith to confirm the correct remote-frequency specification and steps.
Summary
Car key frequencies vary by region and model. Start with the fob’s labeling or your manual, then verify with the manufacturer or dealer using the VIN. Remember there are distinct frequencies for the remote signal and the immobilizer transponder, and when in doubt, consult a professional to ensure you obtain and program the correct replacement key.
