How to Program a Key Fob Without a Working Key (All Keys Lost)
On most cars you cannot program a new key fob yourself without a working key, because the car needs a programmed key to authorize the new one. An automotive locksmith or dealer uses an “all keys lost” procedure: they verify ownership, cut a key from the VIN or lock, then program it through the OBD2 port or the immobilizer module.
Losing your only key is stressful, and the internet is full of tricks that only work when you still have one. This guide explains what is actually possible when you have no working key, what the process looks like, and how to avoid paying more than you need to.
If you still have one working key, the job is far easier and cheaper. Use our main key fob programming guide instead and make a spare today.
Why most cars need the original key to program a new one
Onboard programming procedures were designed as a convenience for owners who already have a key. Most of them start with a working key in the ignition, or require two programmed keys to add a third. That is a security feature: if anyone could add a key with only physical access to the car, the immobilizer would be pointless.
So when every key is gone, the car has to be told about a new key by a tool that can get past its security, usually with a PIN code or by reading data from the immobilizer module.
Your options when all keys are lost
| Option | How it works | Pros | Cons |
|---|---|---|---|
| Mobile automotive locksmith | Comes to the car, cuts a key from the lock or VIN code, programs it with an all-keys-lost tool | No tow, often same day, usually cheaper than a dealer | Not every locksmith covers every model, especially newer European cars |
| Dealer | Orders a key by VIN and programs it with factory software | Works on almost every model it sells | Car usually must be towed in; key may take days to arrive; usually the most expensive |
| DIY with a key programmer | Your own tool runs the all-keys-lost function | Possible on some vehicles | Tool must support AKL for your exact model; a blade still has to be cut |
How the all-keys-lost process works
- Proof of ownership. Expect to show ID and the registration or title in your name. Reputable professionals will not skip this.
- Getting a key cut. The locksmith decodes the lock, or a dealer looks up the key code from the VIN. Laser-cut and high-security blades need special cutting machines.
- Accessing the immobilizer. Depending on the car, the tool reads a PIN code over OBD2, waits through a timed security access, or reads data directly from the immobilizer or body control module (sometimes after removing it).
- Programming new keys. The new keys are written to the car. On most vehicles, any lost keys are erased in the same step, which is good: the old keys will no longer start the car.
- Programming the remote buttons. Sometimes part of the same step, sometimes separate.
Plan on programming two keys while the professional is there. The second key costs much less than another all-keys-lost visit later.
Can you program a key fob without the original key yourself?
Sometimes, but rarely with no tools:
- Separate keyless entry remotes (older cars where the remote only locks and unlocks and a plain metal key starts the car) can often be programmed onboard using just the ignition key. If you lost the remote but still have the ignition key, you are not really in an all-keys-lost situation.
- Some older GM vehicles with Passlock or PK3 systems allow a timed relearn with a newly cut key, which does not require a previously programmed key. Coverage depends on model and year.
- Key programmers with all-keys-lost support can do it on supported cars. Check the coverage list carefully, because many tools list “add key” for a model but not “all keys lost.”
Bluetooth Key Finder Tag
A small tracker on your key ring lets you find misplaced keys with your phone. It costs far less than an all-keys-lost visit.
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How much does it cost without the original key?
All-keys-lost jobs cost more than adding a spare because they take longer and need more expensive tools. Many mainstream cars land roughly between $250 and $600 with a locksmith, and some European models cost much more or must go to the dealer. Towing, after-hours calls and laser-cut blades add to the bill. See key fob programming cost and lost car key replacement cost for detailed ranges.
Before you call anyone: three quick checks
- Search thoroughly. Our guide on how to find a lost car key covers the places keys usually turn up.
- Check for a spare. Family members, the original purchase paperwork envelope, and the glovebox of a second car are common hiding places.
- Check your coverage. Some insurance policies and roadside plans cover key replacement or lockout service.
Frequently Asked Questions
Yes, if they have an all-keys-lost tool that covers your vehicle. Many mainstream cars can be done on site. Some newer European models may need the dealer.
The dealer can usually get the key code and order a key using the VIN and proof of ownership, but the key still has to be programmed to the car, so the car normally needs to be at the dealer.
On most cars, no. An all-keys-lost procedure normally erases all previously stored keys, so a lost key cannot start the car.
Only if the fob can be reset or unlocked and the programmer supports all-keys-lost on your car. Many used smart keys are locked to their first vehicle.
A mobile locksmith often finishes in 30 to 90 minutes. A dealer may need days if the key has to be ordered.