i have a 02 envoy and i had to get anew battery when i got a new battery . now thw keyless remote wont and the truck wont open helpppppppppp plzzzzzzzzzzzzzzzz

You have to re program your fob with the security system. Sit in the driver's seat and close the door. Insert the key into the ignition cylinder, but do not turn it. Press and hold "Unlock" on the driver's door switch. Continue to hold the buttons throughout the process, until otherwise instructed. Turn the ignition to "On," but do not crank the engine. Turn it back to "Off," and then turn it to "On." Turn the ignition to "Off." Let go of the "Unlock" button on the driver's door. The doors should lock then unlock. This lets you know that you have entered programming mode. If the doors do not lock then unlock, start over. Press and hold "Unlock" and "Lock" on the keyless-entry remote. Wait for the door locks to lock then unlock. This takes up to 30 seconds. After the doors lock and unlock, press and hold "Unlock" and "Lock" on the next remote, if you are programming multiple remotes. Wait for the doors to lock then unlock. Turn the key to "On" when you are finished, and then turn it to "Off."

Will that help the truck to open too?