You changed the battery, but your GM vehicle still won’t unlock.

The passive entry works perfectly when you pull the handle, and the engine starts fine once you are inside.

However, the buttons on your key fob are completely dead.

Before you head to the dealership or buy a replacement, there is a strangely simple official factory fix.

But…It might just give your thumb a serious workout.

How to Resync Your GM Key Fob (Step-by-Step)

If your fob buttons are unresponsive but the vehicle still starts, your fob is likely out of sync with the Body Control Module (BCM). Here is the exact procedure to fix it:

  1. Grab the affected key fob. Ensure you are within normal operating range of your vehicle.

  2. Repeatedly press any button on the unresponsive fob.

  3. Keep pressing the button up to 255 times.

  4. Stop pressing as soon as the vehicle begins to respond to the button presses.

That is the entire official factory procedure.

A digital vehicle driver information screen showing the text "Replace Battery In Key" above a "Dismiss" button.
If your dashboard specifically displays this “Replace Battery In Key” message, the 255-press trick won’t help—you actually just need a fresh CR2032 battery!

Why Does it Take 255 Presses?

It sounds like a joke, but it is a legitimate communication error.

The key fob transmitter has simply fallen out of synchronization with the vehicle’s Body Control Module.

By repeatedly pressing the button, you are forcing the fob and the BCM to continuously ping each other.

Eventually, their internal synchronization counters align, and normal function is restored.

Which GM Vehicles Does This Work On?

This specific synchronization issue covers a massive lineup of recent GM vehicles.

If you drive a 2023-2026 full-size SUV like the Chevrolet Tahoe, Chevrolet Suburban, GMC Yukon, or Cadillac Escalade, this applies to you. (Discuss these models in our 2021-2026 Tahoe, Suburban, Yukon, & Escalade Forum)

It also covers the 2024-2026 Chevrolet Colorado (discuss in our 2023+ Colorado & Canyon Forum).

The 2025-2026 Chevrolet Equinox and the 2025-2026 GMC Terrain are affected as well (discuss in our 2025+ Equinox & Terrain Forum).

Many new EVs across Chevrolet and Cadillac are also on the list, including the 2024-2026 Chevrolet Silverado EV, GMC Sierra EV, and GMC Hummer EV.

What to Do if the 255-Press Trick Fails

Sometimes, a rapid-fire clicking session won’t solve the problem.

If you have pressed the button a few hundred times and the vehicle is still not responding, stop clicking.

According to the official bulletin, if this procedure does not correct the concern, further dealership diagnostics are required.

If you end up needing to visit the dealership, make sure to tell your service advisor to look up GM Service Bulletin PIT6456D.

This is the official document, updated in February 2026, that outlines this exact key fob synchronization issue.

Having this bulletin number handy will save you a ton of time and prevent the service department from trying to sell you a new battery or a costly replacement fob.

Frequently Asked Questions (FAQ)

Will this trick work on a standard Silverado 1500?

No, not according to this specific bulletin, but “maybe” in real like. . The official GM document only lists the 2024-2026 Chevrolet Silverado EV, not the standard gas-powered Silverado 1500 but it’s worth trying just in case! 

Do I need a dealer scan tool to do this?

No. While a dealer technician will use a GDS2 tool to verify the internal “Synchronization Counter” is increasing, you can perform the actual resync simply by pressing the fob buttons.

Should I just replace my fob if this happens?

No. The official GM bulletin specifically instructs technicians not to replace key fobs or the Body Control Module for this specific sync concern.

Where can I talk about this with other owners?

Head over to the GM-Trucks.com Forums and join the conversation!