Question 1

How do I spot a fake locksmith before I get ripped off?

Accepted Answer

Three things tell you fast. First, they won't give you a firm price for your specific vehicle on the phone. Second, they show up in an unmarked van with no branding and no way to verify who they are. Third, and this one matters most for a 2003 G35, they can't explain how they're going to program the transponder before they start.

A real locksmith working on this car will tell you upfront whether you're doing an add-a-key or an all-keys-lost job, because the procedure is different and the time is different. If someone shows up and starts guessing, or tells you they'll "figure it out," that's your answer. Ask what tool they use for Infiniti key programming. A vague answer means walk away.

Question 2

What exactly is a remote head key and why does my 2003 G35 need one instead of a regular key?

Accepted Answer

A remote head key is a metal key blade with a plastic head that contains two things: a transponder chip and a small remote for the door locks. On your 2003 G35, the transponder talks to the immobilizer every time you turn the ignition. If the chip isn't recognized, the engine won't start, or it starts and immediately stalls. The remote buttons on the same unit handle lock and unlock separately.

Because both functions live in one piece, a dead fob body or a cracked chip antenna can affect your ability to start the car, not just operate the locks. That's why a plain hardware store key copy cut to the right profile won't work here. The blade can be cut anywhere, but the chip still has to be programmed to your vehicle.

Question 3

What tools do you actually use to program a key for this car?

Accepted Answer

For the 2003 G35, professional OBD-based programming equipment handles both transponder enrollment and remote pairing in one session. This generation supports an add-a-key path when you have a working key present, which is faster and doesn't erase your existing keys. All-keys-lost is a longer job and requires security access to the immobilizer system, but it's still doable on site without a dealer.

I also carry the mechanical decoding tools to originate a key blade when there's no working key to copy from. The cutting and the programming happen at your location, not at a shop.

Question 4

My 2003 G35 starts fine but the remote buttons stopped working. Do I need a whole new key?

Accepted Answer

Not necessarily. On this vehicle the transponder and the remote are in the same key, but they operate independently. If the car starts without any complaints, the chip is fine. A dead CR1616 battery kills the remote functions while leaving the transponder completely unaffected, because the transponder is powered by the car's RF field, not the fob battery.

Swap the CR1616 first. It's a thin cell and not always stocked at every store, so confirm the size before you buy. If a fresh battery doesn't bring the remote back, the fob may have lost its pairing, which is a quick reprogram, or the internal contacts in the key head may be corroded or cracked. Either way, it's not automatically a new key situation.

Question 5

I bought a replacement fob online for my 2003 G35. Can I program it myself?

Accepted Answer

The remote portion of this key does have an onboard relearn procedure for the radio frequency pairing, which some owners have done themselves using an ignition-cycle sequence. However, the transponder chip inside the key head is a separate matter and requires programming equipment to enroll it to your immobilizer. If the key you bought is a complete remote head key with a blank chip, the self-service remote trick won't get the car to start. You'd end up with a fob that operates the locks but a key that stalls the engine.

Bottom line: if you already have a working key and just want to add a second fob, the remote pairing side may be DIY-able on this older platform. But if your bought key has a blank transponder, you still need a tech with the right tools to finish the job.

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