2003 GMC Sonoma Owner's Manual - Page 81

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. 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 in the keyless entry transmitter do the following: 1. Insert an object like a thin coin in the slot between the covers of the transmitter housing near the key ring hole. Remove the bottom by twisting the coin. 2. Remove and replace the battery with a three volt CR2032 or equivalent battery, positive (+) side up. 3. Align the covers and snap them together. 4. Resynchronize the transmitter. See Programmable Automatic Door Locks on page 2-8 for instructions. 5. Check the operation of the transmitter. 2-6