<h1>2021 GMC Sierra HD Keyless Entry Remote Fob (Smart Key)</h1> <p><font size="3"><strong> Important Notice:</strong> The 2021 GMC Sierra HD supports onboard programming only under specific conditions. If you have two recognized smart keys, you can add additional remotes. If no recognized remotes are available, you may still program new ones using the outlined procedure. This process applies only to vehicles equipped with keyless access. </font></p> <p><strong><font size="3">Programming with Two Recognized Transmitters</font></strong></p> <ul> <li><font size="3"> Step 1: Remove the mechanical key from the working remote. </font></li> <li><font size="3">Step 2: Place both recognized remotes inside the vehicle, such as in the cupholder or on the passenger seat. </font></li> <li><font size="3">Step 3: Insert the mechanical key into the door lock on the driver side. Turn the key counterclockwise to the unlock position five times within ten seconds. The instrument cluster will display "Ready for Remote Two." </font></li> <li><font size="3">Step 4: Open the center console. Inside the front portion near the storage tray is the transmitter pocket. Place the new remote into this pocket. </font></li> <li><font size="3">Step 5: Press the engine start button once. The display will confirm that the remote has been successfully added. </font></li> <li><font size="3">Step 6: Remove the remote from the pocket and press the lock or unlock button to confirm functionality. </font></li> <li><font size="3">Step 7: Repeat Steps Four through Six for any additional remotes. </font></li> <li><font size="3">Step 8: When finished, press and hold the engine start button for approximately twelve seconds to exit programming mode. </font></li> <li><font size="3">Step 9: Reinsert the mechanical key into the transmitter body. </font></li> </ul> <p><strong><font size="3">Programming Without Recognized Transmitters </font></strong></p> <ul> <li><font size="3"> Step 1: Remove the mechanical key from the remote. </font></li> <li><font size="3">Step 2: Insert the key into the door lock on the driver side. Turn the key counterclockwise to the unlock position five times within ten seconds. The display will show "Remote Learn Pending, Please Wait." </font></li> <li><font size="3">Step 3: Wait ten minutes. When prompted, press the engine start button. The display will return to "Remote Learn Pending." </font></li> <li><font size="3">Step 4: Repeat Step Three two more times. After the third cycle, all existing remotes will be erased. The system will display "Ready for Remote One." </font></li> <li><font size="3">Step 5: Place the new remote in the center console pocket as described earlier. </font></li> <li><font size="3">Step 6: Press the engine start button. The display will confirm that the remote has been programmed. </font></li> <li><font size="3">Step 7: Remove the remote from the pocket and press the lock or unlock button. </font></li> <li><font size="3">Step 8: To add more remotes, repeat Steps Five through Seven. </font></li> <li><font size="3">Step 9: After programming all remotes, press and hold the engine start button for twelve seconds to exit programming mode. </font></li> <li><font size="3">Step 10: Insert the mechanical key back into the remote.</font></li> </ul> <div id="gtx-trans"> <div class="gtx-trans-icon"> </div> </div>
