It could be the remote has a dead battery. If both remotes don't work, seems like the sensing unit in the car has failed. The remote battery is the easier problem to fix.
The 1989 Buick Park Avenue does not come with a remote keyless entry. The keyless remote entry was not available till 1997.
Follow this link and you're good to go. Let me know if you have any questions. I've done this myself so I know how to do it. .ehow.com/how_7291758_program -remote-1997-buick-lesabre.html#ixzz1HA YkCKDX
To determine if your 2001 Buick Regal LS is equipped with keyless entry, check the owner's manual for features listed under "Remote Keyless Entry." Additionally, look for a key fob; if your vehicle has a fob with buttons for locking and unlocking the doors, it likely has keyless entry. You can also inspect the driver's door for a keyless entry keypad or observe if the doors lock/unlock as you approach the vehicle with the fob. If you're still unsure, contacting a Buick dealership with your vehicle's VIN can provide definitive information.
According to AllData, it is located behind the IPC.
This model never offered keyless entry. It can be made to have keyless entry with after market products.
form_title= Automotive Keyless Entry form_header= Lost your keys? No problem. Get automotive keyless entry. How frequently do you lose your keys?*= _ [50] How long have you owned your vehicle?*= _ [50] Why do you want keyless entry?*= _ [50]
Yes , keyless remote entry
One reason that your keyless entry may not work is that the battery is dead, take it an auto parts store and have the keyless entry battery replaced. If that does not fix it you will need to take it to the dealer to have the keyless entry reprogrammed.
keyless entry system
If there is a touch pad on the drivers door then it has keyless entry.
There are many cars with keyless entry, mine is included (a 2002 ford focus). Keyless entry has been used since around the 90s and have been used ever since. There are still cars without keyless entry but they are all older models.
Each vehicle with keyless entry has its own factory code