<h1>1998 GMC Sierra – Remote Key Fob Programming Instructions</h1> <p><font size="3"> This vehicle allows manual programming of keyless entry remotes using the under-dash diagnostic connector. </font></p> <ul> <li><font size="3">Step 1: Locate the vehicle’s Data Link Connector (DLC), positioned beneath the driver’s side dashboard. The connector is a trapezoid shape, wider at the top. You’ll need to identify pins 8 and 4 — refer to a pinout diagram if the port is not labeled. </font></li> <li><font size="3">Step 2: Inspect the connector to ensure metal pins are present in both pin 8 and pin 4. Once confirmed, use a jumper wire to connect these two terminals. Keep the jumper wire connected for the entire duration of the programming process. </font></li> <li><font size="3">Step 3: After the jumper is in place, the vehicle will enter programming mode. The door locks should automatically lock and unlock once, indicating the system is ready to program remotes. </font></li> <li><font size="3">Step 4: Take the first remote and press the LOCK and UNLOCK buttons simultaneously. Hold both buttons for approximately 15 seconds until the locks cycle again to confirm the remote has been successfully stored. </font></li> <li><font size="3">Step 5: To program additional remotes, repeat the same button hold process for each one within 60 seconds of programming the previous remote. </font></li> <li><font size="3">Step 6: When all remotes have been programmed, disconnect the jumper wire from the OBDII port to exit programming mode. </font></li> <li><font size="3">Step 7: Test all remotes to ensure they operate the door locks as expected.</font></li> </ul>
