Cadillac 2005 CTS - Manual (Page 77)

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.
1. Use a flat thin object to pry open the transmitter.
2. Once the transmitter is separated, use a pencil
or similar object to remove the old battery.
Do not use a metal object.
3. Insert the new battery as the instructions under
the cover indicate.
4. Snap the transmitter back together tightly to be
sure no moisture can enter.
5. Press any button on the remote keyless entry
transmitter to resynchronize the transmitter.
6. Check the operation of the transmitter.
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