Buick 2003 LeSabre Owner's Manual page 79

Battery Replacement
Under normal use, the battery in your remote keyless
entry transmitter should last about four 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.
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.
To replace the battery, do the following:
1. Insert a coin, or similar object, into the notch near
the key ring. Turn it counterclockwise to separate
the two halves of the transmitter.
2. Once the transmitter is separated, use a pencil
eraser to remove the old battery. Do not use a
metal object.
3. Remove and replace the battery as the instructions
inside the cover indicate. Use one Duracell@
battery, type DL-2032, or a similar type.
no moisture can enter.
4. Snap the transmitter back together tightly to be sure
5. Check the operation of the transmitter
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