When do people call us for a key fob?
Most fob calls start with an ordinary annoyance that has turned into a problem. The buttons stopped responding. The case cracked and the circuit board is rattling around inside. The fob went through the wash in a jeans pocket. A dog chewed it. Or the car simply says 'key not detected' on a morning when you need to be somewhere.
The other group of calls is about having only one key. Many drivers realize they own a single working fob only when it goes missing or breaks. A spare is far easier to make while you still hold a working key than after the last one is gone, and we say so plainly when people ask whether it is worth doing now.
A smaller number of calls come from people who bought a used car with one fob, from people who ordered a fob online and can't get it to pair, and from people whose dealer quoted a long wait for a part. All of these are the same craft: identify the exact key system, source or build the right hardware, and program it so the car accepts it.
- Worn-out, cracked, or water-damaged fob that no longer works reliably
- Lost fob, with or without a spare still in hand
- Only one working key and you want a spare before something goes wrong
- Fob bought online that won't program or pair
- Push-button start car that no longer detects the key
- Used car that came with one key or a mismatched remote
What is the difference between a remote, a flip key, and a smart fob?
People use the words 'key fob' for several different pieces of hardware, and the differences decide how the job goes. Getting this sorted out first saves you from buying the wrong part.
A basic remote is a separate unit that locks and unlocks the doors and sometimes opens the trunk or sounds a panic alarm. On many vehicles the remote does not start the car. A separate transponder key does that, and the two are programmed as different functions. Because of that, a car may need a remote and a key addressed separately.
A remote head key, or flip key, combines a cut metal blade with the remote buttons in one housing. It has two jobs to get right: the blade must be cut to fit the ignition and doors, and the electronics must be paired to the car. The blade can be cut correctly and the electronics still fail, or the reverse.
A proximity key, often called a smart key or smart fob, is what most push-to-start vehicles use. It talks to the car over short-range radio, so the car senses the fob near the cabin and allows the start button to work. Many have a hidden emergency blade inside for a dead battery or a dead car. These are the most system-specific fobs, and they are where a careful VIN check matters most.
For deeper background on the chip side of the system, see our page on transponder key programming, which covers how the immobilizer chip and the car's computer agree on which keys belong.
Locked out or need a locksmith now?
We answer around the clock, every day of the year.
Call (213) 577-1366How does a key fob replacement actually work, step by step?
The order of the work matters. Doing it out of sequence is how people end up with a fob that looks right and does nothing. Here is how we approach it.
- Identify the vehicle exactly. We start with the year, make, model, trim, and VIN. Fob hardware can differ within the same model year, so the VIN and the physical key or ignition type settle the question, not a guess from memory.
- Confirm ownership. We ask for proof that the vehicle is yours, typically a registration or title along with your ID. This protects you, and it is a basic professional standard for anyone who makes car keys.
- Check what you have. We look at any existing key or fob, test whether it still has life, note the button layout, and see how many keys the car already knows.
- Pick the right hardware. That means the correct frequency, chip type, button set, and blade profile for your vehicle, in a new unit that is not locked or used by another car.
- Cut the blade if there is one. On flip keys and the emergency blade in smart fobs, we cut by code or by duplicating a working key, then test it in the door and ignition.
- Program the electronics. Using professional programming equipment connected to the car's diagnostic port, we pair the new fob and, where the system requires it, register the transponder or proximity credentials with the immobilizer.
- Test everything. We check lock, unlock, trunk, panic, remote start if the car has it, and the actual starting of the engine. For push-start cars we test starting with the fob in different places in the cabin.
- Go over what you have. We hand you the working keys, explain any quirks, and tell you plainly if anything we found suggests a different problem.
What does a pro check before programming anything?
Programming looks like the quick part, but the checking beforehand is what keeps a job from going sideways.
First, we check whether the car's own receiver and battery are healthy. A weak car battery can interrupt programming mid-process and leave the system in a confused state, so on some vehicles we use a power supply to keep voltage steady during the session.
Second, we ask how many keys the car currently knows. Some systems have a limit on registered keys. Others require you to present every key you want to keep at the time of programming, because the process can erase older registrations and rebuild the list. If you have an old fob you still want working, tell us at the start.
Third, we check for dealer-only situations honestly. A small number of vehicles restrict key programming so that the security data is only available through the manufacturer. When that happens, we say so before any work starts and tell you what your realistic options are, rather than taking a deposit and hoping. Where we can't confirm what a specific vehicle needs from the data in front of us, we confirm by VIN and in person, not from a general rule.
Finally, we look at the fob you give us. A cracked case with an intact board can sometimes be moved to a new shell, which is a lighter-cost route than a whole new unit. A corroded board usually cannot be saved.
- Car battery voltage and general electrical health
- Number of keys already registered and whether old ones should stay active
- Whether the system is open to aftermarket programming or restricted
- Condition of the existing fob, shell, and battery contacts
Locked out or need a locksmith now?
We answer around the clock, every day of the year.
Call (213) 577-1366How do push-to-start and proximity systems change the job?
On a push-button start car, there is no ignition key turning a cylinder. The car checks for a valid fob by radio, then allows the start button to work. That changes a few things for you.
The fob must be registered as a proximity credential. That is a different process from a simple remote pairing. Some cars accept a new fob after a diagnostic-port session, while others need additional security steps first. We find out which kind yours is before we order anything.
If the fob is lost entirely, the 'add a key' route is often unavailable and the work becomes an all-keys-lost job, where the system is reset to accept new credentials. That is a bigger process than copying a fob that still works. If that's your situation, our page on lost car key replacement walks through it in detail.
One thing worth knowing: a push-start car that suddenly stops detecting its fob is not always a fob failure. A depleted fob battery is the most common culprit and the easiest to fix. Radio interference near the car and a faulty interior antenna can also produce a 'key not detected' message. We test the fob before we sell you a new one.
When is a battery or shell swap enough?
We would rather tell you the lighter-cost fix than sell a replacement you don't need. Before replacing a fob, it is worth ruling out a few simpler things.
If the buttons work intermittently or the range has shrunk, a fresh battery may be all it needs. If the case is cracked but the circuit board is healthy, a new shell can hold the existing electronics. If the key blade is worn and the car has trouble turning over, the blade may just need re-cutting.
A replacement is the right call when the board is water-damaged or corroded, when the buttons or the chip have failed, when the fob is lost, or when you want an extra unit. We will test what you have and tell you which category you are in. If the answer is a battery, that is the answer we give you.
What can a key fob replacement not fix?
Honest limits matter here, because a new fob can't solve problems that live elsewhere in the car.
If the key goes into the ignition but won't turn, that points at a worn or damaged ignition cylinder, not the fob. A fresh fob will behave exactly like the old one. That is an ignition problem, and our ignition repair service covers it.
If the fob works for the doors but the engine won't start, the issue may be the immobilizer pairing, a failed chip, or a starter or battery fault. We diagnose which one before recommending parts.
If the car's own receiver, body control module, or interior antenna has failed, no fob will talk to it. This is rare, but it does happen, and we'd rather identify it than let you pay for hardware that can't help.
If you need a full set of keys after losing everything, or want to understand your options across key types, our car key replacement page covers the whole range, with fobs as one part of it. And the car keys overview lays out the different key types side by side.
Locked out or need a locksmith now?
We answer around the clock, every day of the year.
Call (213) 577-1366What affects the cost of a key fob replacement?
We don't quote numbers on a web page, because the honest answer depends on your car. These are the real factors that move the cost up or down.
The first is the type of fob. A basic remote is simpler hardware than a proximity smart key with a hidden blade and a more complex circuit. The more buttons and functions, the more the unit costs.
The second is whether it is an add-a-key job or an all-keys-lost job. Copying from a working key is usually the more economical route. Starting from nothing takes more steps and, on some vehicles, more equipment.
The third is the vehicle's security system. Some are open to professional aftermarket programming without much trouble. Others involve extra security steps or restrictions that add work.
The fourth is the hardware source. A properly matched unit costs more than a mismatched or recycled one, but the cheaper unit often can't be programmed at all. We'd rather sell you one that works.
The fifth is where and when. A van coming to your location, especially late at night, costs more to run than a storefront visit. If you can bring the car to our Westwood shop at 10740 Wilshire Blvd, that's often the lighter-cost way to do it, and we'll tell you so when you call. For general guidance on how we quote, see our pricing page. We give you the full figure before we start work, not after.
Why call Wilshire Lock & Key for a fob?
We have been working as locksmiths in Los Angeles since 1987. That is a long time to see cars change from simple metal keys to chips, remotes, and radio-based smart fobs, and to learn from every generation of it.
We have a storefront at 10740 Wilshire Blvd in Westwood and mobile service vans. If you can bring the car in, you can. If you're stuck in a parking lot or a driveway, a van comes to you. Either way it is one company, not a call center passing your job to whichever subcontractor picks it up. The person who answers the phone is part of the same operation that does the work.
David, the owner and lead technician, oversees the work. If something unusual comes up, such as a dealer-only restriction or a system that needs a second look, it is handled by the people responsible for the business.
One more thing we'd encourage you to do with any locksmith, us included: ask about licensing. California requires locksmith companies to hold a BSIS LCO license, and a reputable company will answer that question directly. It is a simple way to screen out operators who do not take the trade seriously.
Phones are answered 24 hours a day, seven days a week, all year, at (213) 577-1366.
Locked out or need a locksmith now?
We answer around the clock, every day of the year.
Call (213) 577-1366Where do we replace and program key fobs?
Our mobile vans cover 140 cities across Los Angeles County and Ventura County. You can see the full list on our locations page. We handle fobs the same way wherever you are: identify the system by VIN, confirm ownership, program on site, and test before we leave.
If you want a version of this page focused on your area, we have dedicated pages for key fob replacement in Los Angeles, Santa Monica key fob replacement, and key fob replacement in Pasadena, along with many other cities.
If you're not sure whether we reach your address, call (213) 577-1366 and tell us where the car is. We will tell you plainly if it is outside our service area and, where possible, point you toward a sensible alternative.
Frequently asked questions
Can you program a key fob I bought online?
Sometimes. It depends on whether the fob matches your vehicle's frequency and chip type and whether it has already been locked to another car. Many online units are mislabeled or already used, and those can't be reprogrammed. We can check one before you commit, but we can't promise a particular unit will work until we test it against your VIN.
Do I need my old fob to make a new one?
No, but having one makes the job simpler. With a working fob, the process is usually an add-a-key job. Without any key, it becomes an all-keys-lost job, which involves more steps. Either way we can handle it once we confirm the vehicle and your ownership.
Will a new fob make my old one stop working?
It depends on the vehicle. Some systems keep all registered keys active when you add one. Others require every key to be present during programming and may rebuild the list. Tell us which keys you want to keep, and we'll explain how your car behaves before we begin.
What proof of ownership do you need?
We ask for ID plus something that ties you to the vehicle, such as the registration or title. This is standard for responsible car key work, and it protects you from someone else making keys to your car.
Can every make and model be programmed by a locksmith?
No. Many can, but some vehicles restrict programming to the manufacturer or require security access that is not available outside the dealer. We say so up front when we run into one, rather than starting work we can't finish. Because this varies by vehicle and year, we confirm by VIN and in person.
My car says 'key not detected' but the fob looks fine. What should I try?
Replace the fob battery first, since it is the most common cause. Try the emergency blade or the backup start position described in your owner's manual. If that doesn't help, call us. We can test the fob and tell you if the problem is the fob, the car's antenna, or something else.
Is it better to bring the car to you or have a van come out?
If the car drives and you have time, bringing it to our Westwood storefront is often the lighter-cost option. If the car is stuck, you're away from home, or you simply can't leave, a mobile van comes to you. Call (213) 577-1366 and we will talk it through.
Do you make spare fobs, or only replace broken ones?
Both. A spare made while you still have a working fob is usually the more economical route compared with replacing after losing everything, so we encourage people to do it before there is an emergency.
Can a fob be repaired instead of replaced?
Sometimes. A cracked case can often be swapped to a new shell, and a weak battery just needs replacing. Water damage or a failed circuit board usually means the fob needs replacing. We look at what you have and tell you honestly which situation it is.
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Reviewed by David, Owner & Lead Technician, Wilshire Lock & Key — in the locksmith trade since 1987.
Last updated 2026-10-12.