2019 Nissan Altima Key Fob Programming & Replacement Guide

As an ASE-certified electrical technician and professional locksmith, I’ve worked on hundreds of Nissan proximity keys. If you have a 2019 Nissan Altima and have lost a key, need a spare, or are simply dealing with a dead battery, navigating the replacement process can seem daunting. Modern vehicle security has advanced significantly, and the days of simple DIY key programming are largely behind us.

Here is your comprehensive guide to the 2019 Nissan Altima key fob, covering everything from part numbers to programming procedures.

Quick reference

Step-by-step on-board programming

Important Note: The 2019 Nissan Altima features a push-to-start proximity key system. There is no on-board, DIY programming procedure for this vehicle.

In older vehicles, you could often cycle the ignition a few times to enter a programming mode. Because the 2019 Altima uses an advanced Hitag AES immobilizer transponder system with rolling security codes, the vehicle's computer must be accessed directly via the OBD-II port.

To program a new fob to this vehicle, a professional must:

1. Connect a specialized biometric or security-authorized scan tool (like the Nissan Consult III Plus, Autel IM608, or Advanced Diagnostics Smart Pro) to the OBD-II port.
2. Read the BCM (Body Control Module) rolling PIN code.
3. Convert the PIN to an authorization code to bypass the vehicle's security gateway.
4. Program the new smart key directly into the vehicle's immobilizer memory.

Attempting to program this key without the proper professional equipment is impossible. You will need to hire a local automotive locksmith or visit the Nissan dealership.

Battery replacement

If your current fob has simply stopped working, it likely just needs a new battery. The 2019 Altima key fob uses a standard CR2032 coin-cell battery. Replacing it is a simple DIY job that takes less than five minutes:

1. Remove the emergency key: Flip the fob over, slide the small mechanical release latch on the back, and pull the metal emergency key blade out of the bottom.
2. Open the fob casing: Look into the slot where the emergency key was resting. You will see two small notches on either side. Insert a small flathead screwdriver into these notches and gently twist to pry the two halves of the key fob apart.
3. Remove the old battery: Carefully pop the old CR2032 battery out of its housing.
4. Insert the new battery: Place the new CR2032 battery into the slot with the positive (+) side facing down toward the back cover.
5. Reassemble: Snap the two halves of the plastic shell back together tightly, and slide the emergency key blade back into place until it clicks.

Where to buy a replacement fob

If you need a completely new key, you have a few avenues to explore, each with its own pros and cons:

• The Dealership:
  • Pros: Guaranteed OEM parts, guaranteed to work, fast turnaround if in stock.
  • Cons: Very expensive. You can expect to pay anywhere from $250 to $400+ for the fob, the emergency blade cut, and the programming labor.
• Automotive Locksmith:
  • Pros: Often much cheaper than the dealer. Many are mobile and will come directly to your house or workplace to cut and program the key on-site.
  • Cons: You must ensure they have the specific OEM or high-quality aftermarket fob in stock for your 2019 Altima.
  • Price: Typically ranges from $150 to $250 total.
• Amazon / Online Retailers:
  • Pros: The cheapest upfront cost for the fob itself (often $30 to $70).
  • Cons: High risk of receiving a low-quality or incompatible aftermarket fob. Even if you buy it online, you still have to pay a locksmith to laser-cut the blade and program it. Some locksmiths will not guarantee customer-supplied parts.

If on-board programming isn't supported

Because the 2019 Nissan Altima requires diagnostic programming, you need to factor in labor costs when budgeting for a replacement. The immobilizer transponder inside the fob communicates via a high-frequency antenna in the cabin. If the key is not paired to the car's BCM via an authorized scan tool, the push-to-start button will simply not respond, and the dashboard will display a "Key Not Detected" warning.

When calling for quotes, tell the professional your year, make, model, and whether it is a push-to-start model (all 2019 Altimas are). Expect the programming alone to cost between $75 and $150, depending on your region and whether the locksmith has to drive to your location.

Find a mobile locksmith or shop on Repairius.