Door Lock Key Code

I Have a 1987 mercury Sable It Has A key Pad On The Drivers Side Door. How Can I Find Out Or Change The code So I May Lock & Unlock

Help

There should be a unit (in the trunk behind the liner?) that will have a 4 or 5 digit number on it. That is the door code.

There should be a unit (in the trunk behind the liner?) that will have a 4 or 5 digit number on it. That is the door code.

if it a wagon, the door code is on one of the two computer boxes located inside the inside of the spare tire compartment,
watch out for leaks in here as it will kill your door/remote starting
computer. (Thats how I found out about mine.)