If your 1998 Chevrolet Blazer is equipped with a keyless entry system, you will be able to control the locking system using a keyless remote. This remote comes in the form of a key FOB and has three buttons on it. One locks the doors, one unlocks the doors and the third button pops open the back. For the key FOB to work, you must set up your key FOB by programming it through the Blazer programming procedure.
Insert the key into the Blazer ignition, then press and hold the "Unlock" button on the driver side door panel. Continue holding this button throughout the procedure until instructed to release it.
Turn the key as far as it will go without cranking the Chevy engine. This is known as the "On" position.
Turn the key back to the starting position. Known as the "Off" position, this is what the ignition was set at when you first inserted the key.
Repeat steps 3 and 4, then release the "Unlock" button. The doors will lock and unlock to inform you that you have entered the key programming mode.
Press and hold both the "Lock" and "Unlock" buttons on the key FOB for 30 seconds or more. Keep holding the buttons until the door locks cycle on and off again.
Turn the key back to the "On" position to exit programming mode, then test the key FOB.
