1998 Chevrolet Astro Owner's Manual - Page 93
1998 Chevrolet Astro Manual
Page 93 highlights
Battery Replacement Under normal use, the battery in your remote keyless entry transmitter should last about two years. You can tell the battery is weak if the transmitter won't work at the normal range in any location. If you have to get close to your vehicle before the transmitter works, it's probably time to change the battery. To replace the battery: NOTICE: When replacing the battery, use care not to touch any of the circuitry. Static from your body transferred to these surfaces may damage the transmitter. I I L . Use one PanasonicBthree-volt, type CR2032, or equivalent battery. Your transmitter housing snaps apart for ease in battery replacement. Insert a small coin, or flathead screwdriver, to separate the bottom of the transmitter from the top. 2. Remove the battery and replace it with a new one, making sure the positive (+) side of the battery is facing down. 3. Snap the top and bottom together. 4. Test the operation of the transmitter with your vehicle. If the transmitter does not work, try synchronizing the transmitter with the receiver.