2018 Fiat 500 Key Replacement

2018 500 key specs

Every US-market 500 from 2012 to 2019, Abarth included, left the factory with a three-button flip key: lock, unlock and hatch release, with the transponder and remote sharing one head. Parts catalogs most often pair FCC ID LTQF12AM433TX (also printed 2ADFTF12AM433TX) and the Delphi body computer with 2012 to 2017 cars, so on a 2018 or 2019 car read the ID on your own fob first. A buttonless SIP22 transponder key with an ID46 chip makes a low-cost spare; it starts the car and opens the driver's door but can't lock or unlock remotely. No US 500 offered push-button start.

What's specific to the 2018 500

The 2018 Fiat 500 is the seventh of 8 model years in the 500 Type 312 (Mexico-built) (2012–2019), so it shares its key system with the rest of that run, which makes replacement parts easy to source. At roughly 8 years old, a 2018 Fiat 500 has usually seen real wear. Ignition and door cylinders on high-mileage cars wear along with the key, so we cut new keys to factory code rather than copying a worn key. Fob cases crack, buttons wear through and solder joints loosen at this age, so a new shell or a replacement remote often beats repairing the old one. Many have changed hands more than once, so erasing keys you can't account for is worth doing during the visit.

If a newly cut key turns the 2018 500's ignition but the engine cranks and dies, the transponder isn't recognized yet; that's a programming step, not a cutting problem, and it's handled at the car.

Key options for the 2018 Fiat 500

• Flip (switchblade) key. When a flip key is lost rather than broken, the replacement starts from scratch. For a Fiat 500, we confirm the FCC ID, frequency and chip type from the VIN and any remaining key, cut the blade by code, then program both the transponder for the immobilizer and the remote buttons for the doors. Some platforms accept a new flip key through the OBD-II port in a single session; others need a security PIN or a module read before they'll take a new key. Aftermarket flip keys vary a lot in quality, especially the hinge mechanism, so we'll tell you which options we trust for your 2018 500 and which we don't.
• Transponder (chip) key. Transponder chips come in families, such as Texas Instruments 4C and 4D, Philips 46, Megamos 48 and the newer 128-bit AES types, and a Fiat 500 only accepts the one its immobilizer was built around. That's why a hardware-store blank that looks right often won't start the car. We match the blank to the vehicle's chip and keyway before cutting. One more practical note: the chip lives in the plastic head, and when that head cracks, the chip can fall out or shift away from the antenna. If the car starts some days and not others, a damaged head is a frequent reason, and replacing the key before it quits entirely costs less than an all-keys-lost visit.

How the Fiat immobilizer works on the 500

• Fiat's 2012 owner's manual says new 500s ship with a code card listing the key code numbers, and that the first owner is given a four-digit PIN.
• Refurbished Delphi-type 500 flip keys marked LTQF12AM433TX are also sold for 2015 to 2019 Ram ProMaster City vans with the same body computer.
• If the body computer doesn't recognize the chip, the blade still turns the ignition but the immobilizer keeps the engine from running.
• Fiat ended US sales of the gas 500, 500c and Abarth after the 2019 model year.

Programming a 2018 500 key

Programming runs through the OBD-II port with a tool that carries Fiat USA immobilizer software. The tool needs the car's security PIN, which it can often read directly or which can be retrieved by VIN once ownership is confirmed. Aftermarket remote heads usually have to be pre-coded before the car will learn them. After the transponder is accepted, the remote buttons are paired in the same session. All-keys-lost follows the same path once we've cut a working blade from the door lock or by code.

Lost every key to your 500?

Losing every key is fixable on most Fiats, but it takes more than a cut blade. On the 500, 500c and 500L, we verify ownership, decode the SIP22 door lock or cut a blade from the key code, then connect to the OBD-II port, read or enter the security PIN and program a new flip key. If you kept the code card that came with a new car, it speeds up the cutting step. The 500X needs AES-capable equipment, and some push-button or late-model cars involve extra security procedures that we explain on the phone. The Mazda-built 124 Spider depends on tool coverage for its VIN, and the plate stamped with its key code number helps on the cutting side. For the 2024 and newer 500e, plan on a dealer-supplied fob. Have your ID and registration or title ready, and give us the VIN when you call so we can confirm the route before we drive out.

1. Gather your documents and the VIN. Find your registration or title and a government photo ID in the same name. Note the VIN, which is printed on the driver's side of the dashboard and usually on your insurance card. If the paperwork is locked in the car, tell us; we'll open the vehicle first and check it there.
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. Next, the new key is introduced to the car's security system. Many vehicles allow this through the OBD-II port with a PIN or security procedure. Some all-keys-lost cases require reading a module on the bench, and a few platforms only allow dealer programming, which we'll tell you up front.
5. Erase missing keys and add a spare. Once the car starts, we remove the lost keys from memory wherever the system allows, so they can't start the engine if someone finds them. Making a second key during the same visit costs much less than a repeat all-keys-lost call down the road.

Why a spare key pays for itself

• 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.
• A spare stored safely at home rescues you from a locked car with the fob sitting on the seat, a key dropped somewhere along a hiking trail, or a fob that stops responding on a busy morning. Keep it indoors, never in a magnetic box under the bumper.
• 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.

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 500 and your schedule.

500 key battery

If a new CR2032 doesn't bring the fob back, the battery wasn't the problem. Common culprits include a battery holder whose solder joints have cracked from drops, contacts corroded by moisture, worn rubber button pads that no longer reach the circuit, or a board damaged by water. We can test whether the fob is transmitting at all and inspect the board closely. Sometimes a new shell or a resoldered holder solves it; sometimes the fob has to be replaced and programmed. Meanwhile, the car can usually still be started with the fob held at the backup spot described in the owner's manual.

How the job works

1. Identify the exact key your 500 uses. Every job starts with the VIN, the trim and a look at any key you still have. From those we confirm the keyway, the transponder or smart-key chip, the remote frequency, the FCC ID and the button layout. Two Fiat 500 keys that look identical can carry different electronics, so this step keeps the wrong part from ever reaching the car.
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 500, 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 500 key

• The type of key. The biggest factor is technology. A plain mechanical key is a cutting job only. A transponder key adds a chip and programming. Remote-head and flip keys add a circuit board, and a proximity fob for a push-button Fiat 500 is the most involved of all, both in the part itself and in the programming.
• Factory or aftermarket parts. Some owners want an exact factory match; others just want a dependable key that starts the car. Both are reasonable choices. The part you pick changes the quote, so we lay out the options side by side, with the trade-offs in fit, button feel and long-term durability, before you decide.
• 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.
• 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.

Call (951) 903-3193 with your VIN and the keys you still have, and we'll quote the job before any work starts.

Common Fiat key problems

• Used smart keys bought online for the 124 Spider or 500X are often already locked to another vehicle and can't be reprogrammed. Buy new, or ask us to check the FCC ID and part number before you order.
• Inexpensive online Fiat flip keys often arrive locked or uncoded. Many must be pre-coded on a key programmer before the car will learn them, so a key that won't program is often the wrong blank rather than a fault in the car.
• On the push-button 500X, a weak smart-key battery can bring up a key-not-detected message. Fiat's manual says to touch the back of the fob, the side opposite the emergency key, to the START/STOP button, which usually gets you home.
• Buying the wrong remote is a frequent mistake. The 500 and 500c use Delphi-type remotes marked LTQF12AM433TX or 2ADFTF12AM433TX, while the 500L uses the Marelli-type 2ADPXTRF198. The blades match, but the buttons only work on the right car.

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.
• 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.
• Be careful with discount fobs from online marketplaces. A listing may match your remote's shape while using a different frequency, chip or FCC ID, and many used smart keys are locked to their original vehicle. If you already bought one, send us the listing or a photo before the visit so nobody pays for a programming attempt that can't work.

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.

Need a 2018 Fiat 500 key?

Don't wait until the last key disappears. If your Fiat 500 is down to one key, or the one you have is falling apart, call (951) 903-3193. We're a licensed California locksmith, license LCO7891, serving Southern California and the rest of the Inland Empire with mobile car key service every day from 6:30 a.m. to 11:30 p.m.