2020 GMC Sierra 1500 Key Fob Programming Guide

Quick reference

Step-by-step on-board programming

Good news for Sierra owners: if you have at least one working key fob, you can program additional remotes yourself without any special tools. This procedure will program the remote functions (lock, unlock, remote start) of your new fob. However, it will not program the immobilizer transponder chip required to start the vehicle. You will need two programmed fobs to perform this procedure.

1. Take your current, working fobs and your new, unprogrammed fob and get in the driver's seat.
2. Place the first working fob in the center console pocket designed for key fob programming. The owner's manual will show the exact location of this pocket.
3. Start the vehicle by pressing the push-to-start button. The Driver Information Center (DIC) will display a message indicating it is ready for the next fob.
4. Within 5 seconds, remove the first fob and place the second working fob in the console pocket.
5. Press the push-to-start button again. The DIC will update to show it is ready for the new, unprogrammed fob.
6. Within 5 seconds, remove the second fob and place your new, unprogrammed fob into the pocket.
7. Press the push-to-start button. The DIC should display a confirmation message that the new fob has been learned.
8. Press the stop button to turn off the vehicle. Test all buttons on the new fob (lock, unlock, remote start) to ensure they are working correctly.

This procedure only adds a new key; it does not erase existing ones. If you only have one working key, or if you have lost all your keys, you cannot use this DIY method and must see a dealer or automotive locksmith.

Battery replacement

Replacing the battery in your 2020 Sierra fob is simple and requires a CR2032 coin battery.

1. On the side of the fob, there is a small button. Press it to release the emergency key blade.
2. Pull the key blade out of the fob.
3. Inside the slot where the key was, you will see a small indentation. Use the key blade or a small flathead screwdriver to gently pry the two halves of the fob apart.
4. Carefully separate the halves. The CR2032 battery will be visible on one side of the internal circuit board.
5. Note the orientation of the old battery (+ side up/down) and remove it. A small screwdriver can help pop it out.
6. Insert the new CR2032 battery, making sure it is in the same orientation as the old one.
7. Snap the two halves of the fob back together until they click securely.
8. Re-insert the emergency key blade.

Where to buy a replacement fob

• Dealer: The most expensive option, but you are guaranteed to get a genuine OEM fob that is correct for your vehicle. Expect to pay anywhere from $150 to $300 for the fob itself, plus a labor charge (often one hour) for programming. Total cost can exceed $400.
• Automotive Locksmith: A great balance of cost and convenience. Locksmiths can source high-quality OEM or aftermarket fobs and have the professional scan tools required for immobilizer programming. They are often cheaper than the dealer and can come to you. Expect to pay $100-$250 for the fob and programming.
• Amazon/Online: The cheapest way to acquire the hardware. You can find fobs ranging from $30 for an aftermarket version to over $100 for an OEM one. However, the quality can be inconsistent, and you still need a way to program the immobilizer chip. Many locksmiths are willing to program a fob you provide, but they will not warranty the part.

If on-board programming isn't supported

The on-board procedure detailed above only programs the remote control functions. To get the vehicle to start, you must also program the immobilizer transponder chip inside the key fob. This requires a professional-grade diagnostic scan tool that can access the vehicle's security systems. This is not a tool most DIYers own.

When a locksmith or dealer programs the immobilizer, their scan tool communicates with your truck's computer to authorize the new key's unique transponder ID. This security measure prevents someone from simply cutting a key and stealing your vehicle. The cost for this service is primarily labor, often a flat fee or one-hour charge, ranging from $75 to $150, in addition to the cost of the fob itself.

Find a mobile locksmith or shop on Repairius.