Remote unable to unlock doors and turn off alarm after changing batteries in 1995 saab

There's an antenna for the transponder receiver built into the key surround on the 9-5, it could have had a knock or be faulty.

On the 9-5 if the transponder stops working and you get a key not accepted message then you can override it by pushing the unlock button on the key remote with the ignition turned to on and it should let you start the car.

Put key in ignition.
Press unlock button on key fob.
Immobilizer should now recognize it, if it was original fob but car or fob battery was changed or is now low.

Saabs are particular about batteries that are otherwise good, but just below 12 volts.

receiver is hidden away inside the dashboard. it could be the fob is weak or you have something interfering with the fob signals, even a fob going faulty can interfere with its own signal, if you have a spare fob try the difference with that one. if you don't have a spare its best to get one as it may come in handy, it will need programing to the vehicle but it will take up 6 fobs.

If the passkey is messed up, there will be a light on the dash that says security, or have a picture of a car with a lock thru it. If there is no light when the key is turned forward, then its NOT a passkey problem.

try locking and unlocking drivers door lock with the key

After reconnecting the battery press the FOB 5 times that should reset the alar.

Saab's have very specific steps that you must follow when you change the batteries in your key fob. You might try these steps to re-sync your key fob to your security system....

If the battery has been changed outside the
car and the car is locked, proceed as follows:
1 Unlock the front left door with the traditional
key. If the car has a car alarm, this
will be tripped.
2 Open the door and insert the remote
control into the ignition switch. If the car
has a car alarm, this will be silenced.
The remote control and receiver unit are
now synchronized.

sounds like the remote has lost its programming might have to take to dealer if it original equipment if it is aftermarket might have to call manufacturer.

You must LOCK Doors Manualy,then UNLOCK DRIVER DOOR WITH KEY this should Correct the Problem.

if it is a aftermarket alarm, get rid of the alarm, or unlock and lock door w/ key am alarms are a problem when they go awry