Infiniti EX35 Key Replacement

EX35 keys by generation

The EX35's Intelligent Key has three buttons (lock, unlock and panic) and no hatch button. It is listed under FCC ID KR55WK49622 with part numbers in the 285E3-1BA family, runs on a CR2032 coin cell, and stores a mechanical emergency key for the driver's door. The same fob family is used on the 2009-2013 FX, the 2013 EX37 and the 2014-2017 QX50. No turn-key EX35 was ever sold, so every replacement is a programmed smart fob plus a cut blade. EX35 fobs are registered through the OBD-II port after the programmer pulls the security PIN from the body control module. Any fob that is not presented during the session is erased, so bring every working key. With all keys lost, we open the vehicle, cut the emergency blade by code and register new fobs on site. The J50 platform is well supported by professional key programming tools.

Infiniti key security

Nearly every Infiniti sold in the US since 2000 has an engine immobilizer built on Nissan's NATS (Nissan Anti-Theft System). A transponder in the key or fob has to answer the car's challenge before the engine is allowed to run, and the small security light on the dash blinks while the system is armed. The chip inside changed over the years. The 1997-2001 Q45 used a fixed-code Texas 4C transponder, while the G20, I30, I35 and QX4 used the Texas Crypto 4D60. From 2003 the G35, FX and later models moved to the Philips ID46, which stayed in the Intelligent Key fobs of many models well into the 2010s. Infiniti's Intelligent Key lets the car recognize a fob in your pocket; some early cars such as the FX paired it with a turning ignition knob, and push-button start became standard on most models by about 2009. From roughly 2013 the newer fobs use different electronics, and a replacement has to match both the FCC ID and the IC number printed on the original. The QX30 is the outlier: its key system came from Mercedes-Benz.

Infiniti key programming runs through the OBD-II port under the dash. Most models from 2003 on need a security PIN, which professional programmers read or calculate from the body control module (BCM); older NATS cars use a comparable code from the immobilizer side. Two rules catch owners out. First, registering keys usually wipes every key that is not present, so bring all the keys and fobs you want to keep. Second, the replacement has to match the original's FCC ID and part number, and on newer fobs the IC number as well; a fob that looks identical but was built for another model will not register. Used smart keys from about 2013 on are locked to their first car and must be unlocked before reuse. On the newest platforms, including the 2022-on QX60 and 2025-on QX80, tool coverage varies by build, so we check the VIN before promising an all-keys-lost job.

All EX35 keys lost

Losing every key to an Infiniti is often fixable on site without a tow, depending on the model. We verify ownership first, with your ID plus the registration or title, and then open the car without damage. The mechanical blade is cut by key code or decoded from a door lock; most Infinitis from 2000 into the 2020s use the same NSN14-style edge-cut profile (Ilco DA34), with a few older exceptions. On turn-key models that blade gets a transponder head and is programmed over OBD-II. On Intelligent Key models we register new fobs to the car and cut the emergency blade that hides inside each one. Several models are marked limited here because all-keys-lost can need extra procedures or a dealer PIN, and the QX30's Mercedes-based system is a dealer job. We tell you which case applies before any work starts.

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. If the car is locked, we open it with non-destructive tools such as an inflatable wedge and a long-reach rod, or by picking the door lock. Some vehicles need a careful approach to avoid triggering the alarm, which can interfere with programming later.
3. Originate a new key from the car. With no key to copy, the cuts come from the vehicle itself. We retrieve the key code through manufacturer channels where possible, or decode a door lock with a pick-decoder tool. Then we cut the blade on our code machine and confirm it turns the lock smoothly.
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.

Dealer or mobile locksmith?

Dealers have one clear advantage: direct access to the manufacturer's own systems. Some newer vehicles tie key programming to online authorization that only a dealer can use, and certain all-keys-lost situations on specific platforms still require it. A good locksmith knows where those lines are. Where we can do the job, we use professional programming equipment that talks to the same immobilizer and keyless systems through the OBD-II port, and in many cases the result is identical: a properly registered key that starts the car. Where we can't, we can often still help by opening the vehicle, cutting a mechanical blade from code, or helping you gather what the dealer will ask for so that visit goes smoothly. For your Infiniti EX35, ask us directly and you'll get a plain answer.

How the job works

1. Identify the exact key your EX35 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. If you still have a working key, we can read its cuts directly and check them against the factory depths for the Infiniti keyway. A worn key gets corrected back to spec during this step, so the new key turns crisply instead of reproducing years of wear in a fresh piece of metal.
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 EX35, you'll have heard that before we arrived, not halfway through the job.
6. Test everything and clear out old keys. Before we leave, every function gets checked: doors, trunk or liftgate, panic button, remote range, engine start, and the emergency blade in the driver's door. If keys are missing, we delete them from the car's memory where the system allows, so a lost key can no longer start the engine.

What affects the price of an EX35 key

• The type of key. Price follows complexity. The more the key does, the more it costs to replace: brass blade, then chip, then remote buttons, then full keyless entry and push-button start. If your EX35 came with different key styles by trim, the one your car actually uses is the one that sets the quote.
• 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.
• Programming complexity and security access. Two cars with similar-looking keys can program very differently. Newer platforms often guard key programming behind encrypted access or paid credentials, while older systems allow straightforward OBD-II pairing. We check the exact procedure for your VIN before quoting, so the number reflects the real work involved.
• 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.

EX35 key types explained

• Smart proximity key (push-to-start). Proximity keys bring a security trade-off worth understanding. Because the fob is always listening, thieves with relay equipment can stretch its signal from inside your house to the car in the driveway. Keeping the fob away from exterior walls, or in a signal-blocking pouch, closes that gap, and some fobs offer a sleep mode described in the owner's manual. If a smart key for your 2012 Infiniti EX35 is lost or stolen, programming a replacement is the moment to delete the missing fob from the car's memory. And be wary of used fobs from online sellers: a lot of them are locked to the vehicle they came from and can't be reprogrammed to yours.

Why a spare key pays for itself

• 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.
• A spare turns a future all-keys-lost emergency into a simple add-a-key job. With one working key in hand, programming is quicker, and the chip or fob can often be paired without decoding locks or reading modules, which keeps the cost of a lost key far lower.
• 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.

Tips from a mobile locksmith

• 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.
• 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.
• Never hide a spare key or fob on the outside of the car. Magnetic boxes in wheel wells and under bumpers are the first places a thief checks, and with a proximity fob, a hidden key can let anyone open the doors and drive away. Keep the spare at home or with someone you trust.
• 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.

Common Infiniti key problems

• Weak fob batteries are the most common cause of a key-not-detected warning on push-button Infinitis. Most fobs take a CR2032 or CR2025 coin cell, and a fresh battery often clears the warning without any reprogramming.
• Some late-2000s push-button Infinitis can show a steering-lock fault that looks like a key problem: the car refuses to start and the dash flags the steering lock. That points to a column-module repair, not a new fob.
• Programming wipes keys that are not present. Owners who add a spare without bringing every other key often find an old fob suddenly stops starting the car, so gather every key before the appointment.
• Secondhand fobs bought online often fail. Newer smart keys lock to their first vehicle and must be unlocked, and a fob with the wrong FCC ID, IC number or part number will not register no matter how similar it looks.
• On older turn-key models like the I35, G35 and QX4, worn keys and ignition wafers cause sticking or no-turn ignitions. Cutting a fresh key by code, rather than copying a worn one, often solves it.
• Intelligent Key shells crack and emergency-key releases break with age. A replacement shell can reuse the original circuit board, so the fob usually stays registered to the car and does not need a full new key.
• A flashing security light with a key that looks fine usually points to a cracked transponder, a fob with a damaged chip, or an aftermarket remote-start bypass module interfering with the immobilizer.
• A dead 12-volt battery can leave you outside a push-button Infiniti even with a good fob. The mechanical key hidden inside the fob opens the driver's door so you can reach the hood release.

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.