The Key fob LED still lights up, do I still need to replace the battery?

The LED on the key fob requires very little power to light up, The best way to check to see if your battery is still good or needs to be replaced is to unscrew the screw on the back of the fob, pop both batteries out and use a Multi-Meter to test the batteries, they should be at 3.0-3.3Volts, if they are any lower they need to be replaced.