<h1>2025 GMC Sierra HD — Smart Key Remote Fob Programming Instructions</h1> <p><font size="3">The 2025 GMC Sierra HD does not support manual or onboard programming for keyless entry remote fobs. All programming must be completed through the vehicle’s electronic control system using specialized tools. </font></p> <p><font size="3"><b>Smart Key Programming Procedure (Non-Onboard)</b> </font></p> <ul> <li><font size="3">Step 1: Park the vehicle in a safe location and ensure the ignition is off. Close all doors before beginning the programming process. </font></li> <li><font size="3">Step 2: Gather all remote fobs you wish to program. If any existing remotes are still in use, they must be included in this session to remain functional. </font></li> <li><font size="3">Step 3: Connect a professional-grade diagnostic tool to the OBD-II port under the dashboard on the driver's side. </font></li> <li><font size="3">Step 4: Access the programming menu on the tool by selecting the correct vehicle year, make, and model. Follow on-screen instructions to begin remote setup. </font></li> <li><font size="3">Step 5: When prompted, press and hold both the LOCK and UNLOCK buttons on the new remote until confirmation appears on the diagnostic screen or a chime is heard. </font></li> <li><font size="3">Step 6: Repeat Step 5 for each additional remote, if applicable. The system can typically store multiple transmitters. </font></li> <li><font size="3">Step 7: Once all remotes have been successfully paired, save the settings and exit the programming mode. </font></li> <li><font size="3">Step 8: Test every programmed remote to confirm all functions are operational, including locking, unlocking, and remote start (if equipped).</font></li> </ul>
