2020 Chevrolet Silverado 3500HD Key Fob Programming Guide

As an ASE-certified electrical technician and automotive locksmith, I see the 2020 Chevrolet Silverado 3500HD roll into the shop quite often. Whether you use your heavy-duty truck for hauling, off-roading, or managing a fleet, losing a key fob brings your workday to a grinding halt. GM upgraded their security protocols significantly for this generation, but depending on the specific trim and whether you have existing keys, you might still have some DIY options.

Here is your comprehensive guide to programming a key fob for the 2020 Chevrolet Silverado 3500HD.

Quick reference

Step-by-step on-board programming

For the 2020 Chevrolet Silverado 3500HD equipped with Push-to-Start (proximity fobs), GM allows an on-board "Add-a-Key" procedure only if you already possess two recognized, working key fobs. If you only have one working key, or have lost all your keys, you must use a professional scan tool or visit a locksmith/dealer.

To add a third key yourself:

1. Ensure the vehicle is off. Gather your two working remotes and the new, unprogrammed remote.
2. Remove the mechanical emergency key from the unprogrammed remote.
3. Insert the vehicle's original mechanical key into the driver's door lock cylinder. Turn the key to the unlock position five times within 10 seconds.
4. The Driver Information Center (DIC) on the dashboard will display "Ready for Remote #3".
5. Locate the backup key pocket inside the center console (usually at the bottom of the front cup holder or under the rubber mat inside the storage bin).
6. Place the new, unprogrammed remote into the transmitter pocket.
7. Press the START/STOP button. When the remote is learned, the DIC will indicate that it is ready to program the next remote.
8. Remove the remote from the pocket and press the UNLOCK button on the newly programmed remote to verify it works.
9. Press and hold the START/STOP button for 12 seconds to exit programming mode.

Note: If turning the key in the door lock does not trigger the DIC prompt, your specific truck's software may require professional programming.

Battery replacement

If your truck displays a "Replace Battery in Remote Key" message, you need a fresh CR2032 battery.

1. Press the small silver release button on the side or bottom of the fob to slide out the emergency metal key.
2. Look inside the slot where the emergency key was resting. You will see a small pry point.
3. Insert a flathead screwdriver into the slot and gently twist to split the two halves of the plastic fob shell.
4. Carefully remove the old CR2032 battery.
5. Insert the new CR2032 battery with the positive (+) side facing downward toward the back cover.
6. Snap the two halves of the fob back together securely and reinsert the emergency key blade.

Where to buy a replacement fob

When replacing a 2020 Silverado 3500HD fob, you have three main avenues, each with its own pros and cons:

• The Dealership: The most reliable but most expensive option. Expect to pay between $250 and $400 for the OEM fob, plus another $100 to $180 for programming and cutting. Pro: Guaranteed to work. Con: High cost and you have to tow the truck if you have no keys.
• Automotive Locksmith: A mobile locksmith is usually the best balance of cost and convenience. They carry OEM and high-quality aftermarket fobs. Expect to pay $150 to $250 total, and they will drive to your truck's location.
• Amazon or eBay (Online): You can often find aftermarket fobs online for $30 to $80. Pro: Extremely cheap. Con: Quality is highly variable, and many locksmiths will refuse to program customer-supplied fobs because cheap internal boards often fail during the pairing process.

If on-board programming isn't supported

If you have lost all your keys, or your 2020 Silverado is on the newer CAN FD (Global B) electrical architecture that disables DIY programming, you cannot program a new key without professional equipment.

The 2020 HD series utilizes a high-security immobilizer system (AES/Hitag Pro). Bypassing this system requires a high-end diagnostic tool (like an Autel IM608 or SmartPro) that connects directly to the vehicle’s OBD2 port and requests a security PIN from GM's servers. If you find yourself in this situation, expect a professional to charge for diagnostic time and the physical cutting of the high-security HU100 key blade via a CNC key machine.

Find a mobile locksmith or shop on Repairius.