The short answer: sometimes, and the numbers decide
Some fobs bought online can be programmed to your car and some never will be. What matters is whether the new fob matches the original on the inside. Two fobs can share the same shape, logo and buttons and still use a different radio frequency or chip.
That is why we check compatibility first and make no promises for a third-party fob. When the numbers line up, there is a fair chance it pairs. When they don't, programming can't fix it, and it is better to learn that on the phone than in your driveway.
Where to find the numbers that matter
Flip your working fob over, or open the case the way you would to change the battery. Look for tiny printing on the back, under the battery or on the circuit board. The new fob, or the seller's listing, should show the same details.
- FCC ID: a short code of letters and numbers on most fobs sold in the US. It identifies the radio inside and is the first thing to compare.
- Part number: usually near the FCC ID or on a sticker inside. Carmakers sometimes switch parts partway through a model year, so this catches mismatches the FCC ID misses.
- Frequency: shown in MHz on some fobs and listings. A fob on the wrong frequency can't reach the car at all.
- Buttons: remote start, power liftgate or sliding-door buttons only work if your car has those features and the fob is the version made for them.
- Blade: a flip key or a smart key with a hidden emergency key needs a blade that fits your locks. Blades bought online arrive uncut.
Warning signs in an online listing
- "Used", "pre-owned" or "pulled from a working car". Many smart keys and some remotes lock themselves to the first car they learn and turn down a second one.
- One listing that claims to fit a long run of years and several brands. Those fobs tend to suit some of the cars named and miss the rest.
- No FCC ID or part number anywhere, in the listing or on the fob.
- "Shell only" or "case only": an empty housing with no electronics, meant for moving your old circuit board into a fresh case.
- A blade that feels light or flexes in your fingers. Soft metal may not cut cleanly.
Can you program it yourself?
On some older cars, a basic lock-and-unlock remote can be paired with a routine from the owner's manual, such as turning the ignition on and off in a set order. If your manual lists one, it is safe to try.
Starting the engine is a separate system. The car's immobilizer must learn the chip in the key or fob, and on most vehicles that takes programming tools connected under the dash. Smart keys for push-button start nearly always fall in this group, as our push-to-start smart key page explains.
What to have ready when you call
- The year, make and model, plus the trim if you know it.
- The FCC ID and part number from the new fob, and from your current one if you still have it.
- How many working keys you have. If none, read all keys lost as well.
- Every key and fob you still use. On many cars, adding a key means registering all of them again in the same session.
- Where the car is parked, plus your photo ID and the registration or title, which we look at before any key is made.
We tell you how the match looks, and the price is explained on the phone before we drive out. If the fob looks wrong for your car, we say so, and you can ask about a key we bring instead.
What happens at the car
Your locksmith looks over the fob before connecting anything, checking the chip and frequency as far as the tools allow. If it has a blade, the blade is cut on the key cutting machine in the service vehicle and tried in the door, and in the ignition if the car has one.
Then the fob is programmed and every button is tested: lock, unlock, trunk or liftgate, panic, remote start if you have it, and the engine start. If the online fob refuses to program, we stop and tell you what we found. Any other option, and its price, is explained before more work begins.
When an online fob makes sense
A matched online remote has a better chance on an older car with a separate metal key. On a newer push-to-start car, a fob from an unknown seller is more of a gamble, and a spare key we bring may be simpler.
If your current fob just stopped working, it may not need replacing. Try a fresh battery first, then see key fob not working for other causes.