The truck is bought, the title is signed, and the seller handed you exactly one key. Somewhere out there may be a second key, a third, and a spare the previous owner forgot about in a kitchen drawer. Call or text (817) 214-2934 and we will tell you which half of this problem you actually have.
Quick Answer
As of September 2026 in Granbury, rekeying a vehicle's mechanical locks runs $50–$150 per lock, with most used-vehicle jobs landing in the $75–$200 range for the doors and ignition together. Erasing previously learned electronic keys from the immobilizer falls in the $80–$350 programming band. Those are two different jobs solving two different risks, and on a modern vehicle you usually need both — rekeying the locks does not erase an old electronic key, and erasing keys does not stop an old metal key opening your door.
The Two Locks on Your Vehicle
Every vehicle built in the last thirty years has two independent security systems, and people buying used cars almost always think about only one of them.
The mechanical lock. The metal blade, the wafers inside the door cylinder and the ignition, the physical act of turning something. This is what stops someone opening the door and rummaging through the console.
The electronic immobilizer. The chip in the key, the antenna around the ignition or the receiver in the body control module, the handshake that lets the engine run. This is what stops someone driving away.
A previous owner holding an old key holds both. A previous owner holding an old key that has been erased from the immobilizer still holds the first one — they can open your doors, they just cannot drive off. And a vehicle whose locks were rekeyed but whose immobilizer was never touched has the opposite gap on a push-to-start vehicle, where there is barely a mechanical lock to rekey in the first place.
Getting this distinction right is most of the value in this article, because it is the difference between spending money on the correct job and spending money on half of it.
Granbury Rekey and Erase Pricing
| Job | Typical Granbury range (September 2026) | Notes |
|---|---|---|
| Rekey one door lock cylinder | $50–$150 | Per lock; decoded and re-pinned to a new key |
| Rekey doors and ignition together on a used vehicle | $75–$200 | The usual used-vehicle package |
| Ignition lock cylinder replacement instead of rekey | $100–$350 | When the cylinder is worn rather than just unknown |
| Erase previously learned keys from the immobilizer | $80–$350 | Programming band; feasibility is platform-dependent |
| New key cut and programmed at the same visit | $75–$350 | Cheaper bundled than as a separate call-out |
| Push-to-start proximity fob added or re-paired | $200–$600 | Proximity electronics cost more than remotes |
| Full peace-of-mind package: rekey plus erase plus one new key | Quoted as one number, always below the sum of separate visits | One trip out to Hood County instead of three |
These bands are the ones published across this site, including on our car lock rekey and repair service and our car key replacement page. We quote the all-in number for your specific vehicle before anything is opened up.
Which Half Do You Actually Need?
Run through this and the answer usually falls out on its own.
If the vehicle is a push-to-start with a proximity fob: the electronic side is almost the entire risk. There is a mechanical emergency blade hidden in the fob and a matching keyway on the driver's door, but nobody is casually opening your truck with it. Prioritise erasing previously learned fobs, in the $80–$350 band.
If the vehicle is older and uses a plain metal key with a chip in the head: you need both. The metal blade opens the doors; the chip starts the engine. Rekeying alone leaves them unable to start it but still able to get in. Erasing alone leaves them able to get in but not drive away.
If the vehicle is old enough to have no chip at all — and plenty of the farm and ranch trucks around Hood County are — then there is no immobilizer to erase and rekeying the mechanical locks is the whole job. That is also the cheapest version of this by a comfortable margin.
If you genuinely cannot tell which you have: look at the head of the key. A thick moulded plastic head usually means a chip. A thin all-metal head usually does not. Our transponder key guide for Granbury walks through how to tell, and what the chip is actually doing when you turn the key.
Can Old Keys Really Be Erased?
Honestly: usually, but not universally, and the difference matters before you pay.
On many platforms, programming a fresh set of keys as though every key were lost causes the immobilizer to forget everything it previously knew. Any key not present during that procedure stops working. That is the clean outcome and it is the common one.
On other platforms, adding a key is genuinely just adding — the module keeps its existing list and a separate erase procedure has to be run. That is still routine, it just has to be asked for explicitly, which is exactly why "rekey the truck I just bought" needs to be a conversation rather than a checkbox.
On a small number of vehicles — certain European marques, some very recent platforms with a locked security gateway — a full key erase needs manufacturer credentials we cannot obtain at the roadside. When that is your vehicle, we tell you on the phone rather than after a trip out to Lipan. There is no version of this where discovering it in your driveway is acceptable.
The related honest note: the number of keys a module can hold is finite and varies by platform. On some vehicles it is four, on others eight or more. If you are near that ceiling, an erase is not optional even if you only want to add one key — there is no room left.
The Used-Vehicle Situations We See Most in Hood County
The private sale with one key. Overwhelmingly the most common. The seller is not being sinister; they lost the spare years ago and never replaced it. You inherit a vehicle with a single point of failure. The fix is one key plus, if the platform allows it, an erase. Do it in one visit and you pay one trip charge.
The auction or estate vehicle. Nobody knows how many keys ever existed, and there is no one to ask. This is the strongest case for a full erase — not because anyone is coming for the truck, but because you cannot audit what you cannot see.
The repossession or recovered vehicle. Same logic, more urgency. Rekey the mechanical locks and erase the immobilizer, and do both.
The dealer trade-in bought off a small lot. Worth asking a plain question: how many keys came in with it? A straight answer costs nothing. An evasive one tells you to budget for the erase.
The work truck changing hands within a business. Different problem, same tools. When a driver leaves, the keys they had should stop working, and that is a rekey plus an erase exactly as it is for a private sale.
What This Costs Compared With Doing Nothing
Doing nothing is free until it is not, which is unsatisfying but true. The honest framing is not fear, it is this:
The single key you were handed is now the only key in existence that you know about. If it is lost, damaged, or left in a locked truck at a boat ramp, you are in an all-keys-lost situation — the most expensive version of every job on our price list, because the vehicle has to be convinced from scratch. On a proximity vehicle that is the $250–$600 band rather than the $200–$500 one, plus whatever waiting period the manufacturer imposes.
So the second key is not really a security purchase. It is the cheapest insurance in vehicle ownership, and it costs least on the day you still have one key working. We make the same point in our guide to getting a spare car key in Granbury, and it is the single piece of advice we repeat most often.
If you have already crossed that line and no key exists at all, it is still solvable — see whether a locksmith can make a car key with no original for how that job actually runs.
What About the Ignition Cylinder?
Sometimes the right answer on a used vehicle is not to rekey the ignition but to replace it.
A worn ignition cylinder on a high-mileage truck will accept a sloppy old key and reject a freshly cut, dimensionally correct one — which feels like the locksmith made a bad key but is actually the lock telling you it has been worn oval by twenty years of a heavy keyring. Rekeying a worn cylinder puts new wafers into a tired housing and the problem returns.
Replacement sits in the $100–$350 ignition band and includes fitting and testing a key. On most vehicles the new cylinder can be keyed to match your door locks so you still carry one key rather than two. Whether yours needs it is a five-minute assessment, not a guess — the tell is usually that the key has to be jiggled, lifted, or held at an angle to turn, which our write-up on a key that will not turn in an older vehicle covers in detail.
What We Need Before We Come Out
- Year, make, model, and trim
- How many keys exist, and whether every one of them is in your hand
- Whether the vehicle is push-to-start or uses a turn key
- Proof of ownership: title, registration, or insurance in your name, with photo ID
- Where the vehicle is parked
The ownership check is not a formality, and it is the point where a used-vehicle job differs from every other kind. A recently signed title is fine. A bill of sale plus ID is usually fine. What is not fine is making keys for someone who cannot tie themselves to the vehicle, and a locksmith who skips that step on your car will skip it on somebody else's — the reasoning is in our guide to vetting a locksmith in Granbury. In Texas, locksmiths are licensed through the Department of Public Safety Private Security Program, and asking to see that is a fair question at any doorstep.
How the Job Runs
A used-vehicle rekey in Granbury usually takes forty-five minutes to two hours, depending on how much of it you want done.
We confirm the vehicle and check ownership. If the mechanical locks are being rekeyed, we remove the door cylinder, decode it, re-pin it to a fresh key, and refit it — then repeat for any other lock you want matched. If the immobilizer is being cleared, we connect to the diagnostic port and run the platform's erase-and-relearn procedure with your new keys present. Then we test everything: every door, the ignition or start button, the trunk or tailgate, and the remote functions.
The last step matters and it is the one people forget to ask about. Before we leave, we confirm that the vehicle starts on every key you now hold, and that any key not in your hand no longer does anything. That is the entire point of the visit.
One Thing Worth Doing the Same Week
Whatever you decide about rekeying, get a second key made while the first one still works.
Half the used-vehicle calls we take in Hood County are not about the previous owner at all. They are from somebody who bought a truck with one key six months ago, lost it in a pasture or a lake, and is now paying the all-keys-lost price on a vehicle they could have covered for far less at any point in between. On a modern truck that gap is frequently $200 or more — the same pattern we see on the Chevy Silverado transponder and remote-start jobs that come through here most weeks.
Bundle it into the rekey visit and you pay one call-out instead of two.
Frequently Asked Questions
How much does it cost to rekey a car's locks in Granbury? As of September 2026, $50–$150 per lock, with most used-vehicle jobs covering the doors and ignition together at $75–$200. Erasing old electronic keys from the immobilizer is a separate job in the $80–$350 programming band. We quote the combined number before starting.
I bought a used car with one key. Do I really need to rekey it? It depends on the vehicle. On a push-to-start, erasing previously paired fobs matters far more than the mechanical locks. On an older chipped-key vehicle you want both, because a rekey stops someone driving it and an erase stops nothing about them opening the door. On a pre-chip truck, rekeying the locks is the whole job.
Can you erase the previous owner's keys so they stop working? On most platforms yes — programming a fresh set as an all-keys-lost relearn makes the module forget everything it previously knew. On some, erasing is a separate procedure that has to be requested. On a few vehicles it needs manufacturer credentials, and we tell you that on the phone rather than after a trip out.
Does rekeying the door locks also stop the old key starting the engine? No, and this is the most common misunderstanding. Rekeying changes the mechanical wafers only. If the old key has a chip the engine still recognises, it can still start the vehicle once inside. The two systems are independent and have to be dealt with separately.
Is rekeying cheaper than replacing the locks? Almost always, and it is usually the better result too. Rekeying keeps your original hardware, matches everything to one key, and avoids mismatched replacement cylinders. Full replacement makes sense when a cylinder is physically worn or damaged rather than simply of unknown key history.
Can you match my new key to every lock on the vehicle? Usually yes — doors, ignition, and often the tailgate or trunk can all be keyed alike so you carry one key. It is far cheaper done in a single visit than lock by lock later, because you are only paying one trip out to Hood County.
Do I need to prove I own the car? Yes, on any job where keys are made or erased. Title, registration, or insurance in your name alongside photo ID is the normal set, and a recently signed title from a private sale is fine. Any locksmith who does not ask is one to be wary of.
How long does a used-vehicle rekey take? Typically forty-five minutes to two hours in your driveway, depending on how many locks are being rekeyed and whether the platform imposes a security waiting period during the immobilizer relearn. We tell you which applies to your vehicle before we start.
Get One Number for the Whole Job
Send us the year, make, model, how many keys exist, and whether the vehicle is push-to-start, and you will get a single figure covering the rekey, the erase, and any new keys. Call or text (817) 214-2934, weekdays 8:00 AM to 7:00 PM, Saturdays 8:00 AM to 5:00 PM, with 24/7 emergency availability. You can also request service through our contact page or read our auto locksmith services and costs guide for the full price list.
Sources
- Texas Department of Public Safety — Private Security Program
- Texas Department of Motor Vehicles — buying a vehicle and title transfer
- National Insurance Crime Bureau — vehicle theft resources
- National Automotive Service Task Force — Vehicle Security Professional Program
- Federal Trade Commission — buying a used car
- Associated Locksmiths of America