Toyota Mirai Key Replacement

Mirai keys by generation

The second-generation Mirai uses a four-button smart key with lock, unlock, trunk and panic buttons; catalogs list FCC HYQ14FLA under Toyota parts 8990H-62030 and 8990H-62140, powered by a CR2032. Entry is by touching a door handle, and the car starts with the POWER button whenever the fob is inside the cabin. An emergency blade slides out of the fob for the driver's door. This is a different fob from the first-generation car's, so the two generations can't share keys. New fobs must be registered with professional equipment; there is no on-board method. On current tools, adding a fob to this generation usually involves online data for Toyota's 128-bit smart system, and some cars need a direct connection at the smart key ECU. All-keys-lost is less widely supported than on high-volume Toyotas, so we confirm by VIN first and will tell you plainly if a Toyota dealer that services fuel-cell vehicles is the better route.

First-generation Mirais use a four-button proximity fob with lock, unlock, trunk and panic buttons; catalogs list FCC HYQ14FBA under Toyota part 89904-62020. Touching the door handle with the fob nearby unlocks the car, and the POWER button starts the fuel-cell system whenever the fob is inside. An emergency blade slides out of the fob for the driver's door. There is no key slot or conventional ignition anywhere on the car. There is no on-board programming for Mirai fobs. A new fob is registered with a programmer through the OBD-II port and the smart key system, after which the emergency blade is cut to the door lock. Aftermarket tool coverage for the Mirai is thinner than for the Prius or Camry because so few were sold, so we check your VIN against our equipment before scheduling. All-keys-lost may require direct access to the smart key ECU or a visit to a Toyota fuel-cell dealer.

Toyota key security

Toyota phased in transponder immobilizers model by model, so two Toyotas from the same year can need very different keys. Starting with the 1998 model year, the Camry, Avalon, 4Runner, Sienna and Land Cruiser used a fixed-code Texas 4C chip, while US Corollas, the Echo and other economy models kept plain mechanical keys into the mid-2000s. Between 2003 and 2005, depending on the model, the encrypted Texas 4D-67 chip took over. Around 2010 came the 80-bit G chip, and from about 2014 the 128-bit H chip, also called 8A. Many of these later keys carry a stamped D, G or H on the blade. Smart keys spread to US Toyotas with cars like the 2004 Prius, 2005 Avalon and 2007 Camry, moved to 128-bit fobs in the 2010s, and since about 2022 Toyota has used a newer generation: Texas 8A BA-type fobs in models such as the bZ4X and Crown, and NXP Hitag AES, often called 4A, in the Corolla, Corolla Cross and 2025 Camry. Partner-built cars follow their partner's rules, so the 86 and GR86 use Subaru systems and the GR Supra uses BMW's. The letter on your blade, the FCC ID on your fob and your VIN tell us which system we are working with.

Most Toyota key work runs through the OBD-II port with professional equipment. On 4C cars, a spare can often be cloned from a working key onto a new chip, while 4D-67, G and H keys are registered to the immobilizer itself. Some 4D-67 and G-chip Toyotas also accept an on-board add when you have a working black master key, and Toyota's door-and-key routine pairs most separate remotes and remote-head buttons without a computer. Smart keys always need a programmer. Many 2004-2020 fobs can be professionally reset and reused, but fobs from the newest systems may not be reusable at all. Blades matter too: most Toyota chip and remote-head keys use the TR47 profile, while smart keys hide a laser-cut emergency blade that has to be cut so you can open the driver's door when the fob dies. Before any of this, we check your ID and registration, and we quote the whole job before starting.

All Mirai keys lost

Losing every Toyota key is solvable in most cases, but the method depends on the system. On 4D-67 and G-chip cars, our equipment resets the immobilizer through OBD-II, usually after a built-in security wait, and then registers new keys. H-chip and 8A smart key cars usually need an emulator or a direct connection at the immobilizer or smart key box, which can mean removing a panel under the dash. Older 4C cars and early smart key systems may need the module's memory read on the bench. Toyota's newest BA and Hitag AES systems have aftermarket all-keys-lost coverage on many models but not all, and the BMW-built GR Supra is a dealer job. We confirm your VIN before driving out, verify ID and ownership on site, and program at least two keys.

1. Gather your documents and the VIN. Call with the year, make, model and VIN if you can read it through the windshield, plus where the car is parked. Those details let us confirm whether your Toyota Mirai can be done on-site and bring the right key, so the first trip is the only trip.
2. Get into the vehicle without damage. Entry comes before key-making because we need access to the ignition, the OBD-II port and sometimes the documents in the glove box. We take care with weather stripping, door frames and paint, and we confirm the dash VIN matches your registration before going any further.
3. Originate a new key from the car. Originating a key means building it without a sample. The door lock usually reveals most of the cuts; any it doesn't are worked out by test-cutting and trying the ignition or a second lock. The finished blade should feel like a factory key, not a forced fit.
4. Program the key to the immobilizer. All-keys-lost programming often takes longer than adding a key, because the car has no trusted key to authorize the change. We follow the procedure your Toyota Mirai requires, then confirm the engine starts and keeps running and the remote or keyless functions respond.
5. Erase missing keys and add a spare. A lost key's metal blade can still open your doors even after its chip is erased. If the keys disappeared along with something showing where you live or park, consider rekeying the car's door lock cylinders too. We'll also recommend leaving with two working keys, not one.

Dealer or mobile locksmith?

Price and parts are the other half of the comparison. Dealers typically sell factory keys only and charge their posted service rates for programming. We offer factory keys where it matters and quality aftermarket alternatives where they perform well, and the quote covers cutting, programming and the trip, with nothing tacked on at the end. Timing differs too. Dealer service departments generally keep business hours, while we take automotive calls every day from 6:30 a.m. to 11:30 p.m., which covers early commutes and late evenings. We're closed overnight, and we'll be upfront if your timing means the dealer or a next-day visit is the better plan. Neither option is wrong; the right one depends on your Mirai and your schedule.

How the job works

1. Identify the exact key your Mirai uses. We ask a few quick questions on the phone: the year, whether the car starts with a turn key or a button, how many keys you have left, and whether the remote still works the doors. Then we check the VIN against our programming references so the van arrives with the correct blank or fob, not a close guess.
2. Verify ownership before any work. California holds licensed locksmiths responsible for knowing whose car they're making keys for. We record your name, the VIN and the plate on a work order. If you aren't the registered owner, you'll need the owner's written authorization along with your own photo ID before we begin.
3. Get the key code or decode the lock. A key is cut from a code, not a guess. When the factory code can be retrieved through manufacturer channels after ownership is verified, we use it. When it can't, we decode a door lock with a pick-decoder tool that reads the wafer positions without damaging anything, then work out any missing cuts.
4. Cut the blade on-site. Cutting happens right beside your car. For a smart key, that means the emergency blade hidden inside the fob; for a transponder or remote-head key, it's the main blade you'll use every day. We deburr the cuts and check the fit in each lock so nothing binds or sticks later on.
5. Program the chip, remote or smart key. Programming tells the car's computers that the new key belongs to the vehicle. Transponder chips are added to the immobilizer, remote buttons to the body control module, and proximity fobs to the keyless system. If a step requires dealer-only access on your Mirai, you'll have heard that before we arrived, not halfway through the job.
6. Test everything and clear out old keys. The last step is a short walkthrough. We show you how many keys the car now recognizes, point out the dead-fob start method for your vehicle, and hand you an itemized receipt. If a spare makes sense, it's simplest to add it during this same visit while the equipment is already connected.

What affects the price of a Mirai key

• All keys lost or adding a key. Adding a key while a working one is in hand is the simpler job. With every key gone, we may have to open the car, decode a lock to originate the cuts, and run a longer programming routine, so all-keys-lost work takes more time and costs more.
• Programming complexity and security access. Some immobilizers accept a new key with a few on-board steps. Others need a PIN code, a timed security wait, manufacturer online access, or removing a module to read its data. Every extra layer of security on the Toyota system adds equipment time and labor to the job.
• Blade style and cutting. The blade still matters on keyless cars, because the emergency insert has to fit the door lock. Cutting by code is standard for us. Decoding a door lock when no key or code exists adds time, and so does progressing any cuts the door lock doesn't show.
• Travel, timing and extra repairs. Sometimes a key problem is really a lock problem: an ignition that won't turn even with the right key, or a door cylinder that has been jammed for years. Fixing those is separate work. We point them out, explain the options, and quote the whole job up front so the bill holds no surprises.

Mirai key types explained

• Smart proximity key (push-to-start). A smart or proximity key lets a 2026 Toyota Mirai open when you touch the door handle and start with a push of a button while the fob stays in your pocket or bag. Antennas in the doors and cabin send out a low-frequency wake-up signal; the fob answers on a higher radio frequency with an encrypted reply, and the car only allows a start once it confirms the fob is inside. When the fob battery is weak, that conversation fails, which is why most designs include a backup: hold the fob against the start button or set it in a designated pocket. The owner's manual shows where, and it's worth checking before you need it.

Why a spare key pays for itself

• Some vehicles make it hard to add a key once you're down to one. Certain immobilizer systems let an owner program an extra key on-board only when two working keys are present, so a second key preserves the easy options for later and avoids a full reset.
• Electronics fail without warning. A fob dropped on concrete, run through the washing machine or soaked at the pool can quit for good. With a second programmed key, that's an annoyance you fix on your own schedule, not a stranded car that needs attention today.
• When you sell or trade in the vehicle, buyers and dealers expect two keys. A missing key can come up during an appraisal or a private-sale negotiation, so having both on hand keeps the conversation about the car, not about what it will cost the next owner to replace one.

Tips from a mobile locksmith

• Every so often, use the mechanical blade in the driver's door lock. Cylinders that go years without a key can seize from dust and dried grease, and you won't find out until the day the fob dies and the blade is your only way in. A small shot of dry lubricant keeps the lock ready.
• On any vehicle with a turn-key ignition, keep the key ring light. A heavy cluster of keys, tools and charms swings with every bump and slowly wears the ignition wafers and the key itself. When the key starts to stick or needs a wiggle to turn, deal with it early, before it stops turning entirely.
• Southern California heat is hard on keys. Fob batteries drain faster, plastic housings turn brittle, and rubber button pads crack when a key spends summer afternoons on a dashboard or in a sunny cup holder. Carry the fob with you or keep it shaded, and replace batteries before summer rather than after they fail.
• Make the spare before you need it. Adding a key while one still works is quicker and less expensive than starting from nothing, and it keeps the simpler programming options available. Good moments are right after buying the car, or as soon as one of your two keys goes missing.

Common Toyota key problems

• Toyota chip keys are easy to mix up. Many later keys are stamped near the head with D for the 4D-67 chip, G for the 80-bit G chip or H for the 128-bit H chip, and a key ordered by looks alone often won't program.
• Toyota fob batteries vary by family. The 2009-2012 Camry-style smart key takes a CR1632, many 2016-2022 fobs take a CR2032, and larger 2022-and-later fobs take a CR2450. Most remote-head keys use a CR2016, while older separate remotes use a CR2032.
• If a smart key battery dies, most push-button Toyotas will still start. Press the brake and touch the Toyota emblem side of the fob to the start button; the car reads the chip directly, so a flat cell isn't a lockout.
• Many newer Toyota fobs have a battery-saving mode, switched on by holding lock and pressing unlock twice. Afterward the car ignores the fob in your pocket until a button is pressed, which owners often mistake for a dead key.
• Toyota smart keys look alike across models but carry different FCC IDs and board numbers. Suppliers warn, for example, that a 2007-2010 fob with an E board won't substitute for one with a numbered 0140 board.
• Remote-head keys take a beating on a key ring: the plastic head cracks and the rubber button pad tears. The chip and circuit board usually survive, so a new shell and freshly cut blade often fix the problem.
• Older Toyotas came with black master keys and gray valet keys. The valet key starts the car but can't be used for Toyota's on-board method of adding keys, so a car with only valet keys left needs programming equipment.
• A used Toyota smart key bought online is already locked to its first car. Many 2004-2020 fobs can be professionally reset for reuse, but fobs from the newest systems may not be resettable, so buying used can waste money.

Proof of ownership

Before we cut or program a key for any vehicle, we verify that you have the right to it. Please have two things ready: the current registration or the title, and a government-issued photo ID with a matching name. We also check that the VIN on those documents matches the VIN plate on the dashboard. If the registration is locked inside the car, that's fine; we open the vehicle first, check the paperwork in the glove box, and only then make the key. If something doesn't line up, we stop and sort it out before any key is made.