Doors will not open by using remote key pad

Hi. It sounds like the door lock has failed. This would need to be replaced. You will have to break the door pad to access the lock.

1) Key turns but dose not unlock door. This means that the rod that goes to the back of the lock has came off. This also means that is the reason door is not unlocking with the remote as it pops the lock rod inside the door which pushes the lock open.
2) Key does not turn lock at all but works passengers side door. This means that the locks has been changed in the door, but that doesn't sound like the problem as you say the remote doesn't open the drivers side door so more than likely the rod has came off the back of the lock

Sounds like the security system is armed. It is designed to disable the starter. If you don't have a key fob for the alarm, try locking and un-locking the driver's door with the key to disarm. If that doesn't work, look for a very small black button or toggle switch that will either be taped to wiring under the driver's side or the dash, or mounted to the very bottom of the dash above the driver's legs.

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.

Either via an actual theft attempt or you (or someone with your keys) not realizing that you/they actually armed the vehicle and opened the door or trunk afterwards.

Essentially this sounds like the vehicle was entered after being armed and the proper precedures not met to reset it.

The car may just need to be locked from the outside with the key (not the remote or keyless entry) while the doors are closed and windows are up, and then also unlocked with the key...

However it sounds as though you have perhaps driven it since then. If this is the case

You may want to check all your fuses and replace the ones affected by the anti theft system.
Security - Pwr Locks - Horn - Pwr Trunk Release _ Int Lights - and maybe The Emergency Flasher as well.

Be sure and check under the Dash, Hood and under the Back seat.

Cadillac recommends after a theft attempt, the vehicle may need to be serviced. So I recommend going through the fuses first, even replacing the battery in your remote fob and then if the problems still persist. have the vehicle serviced.

Good Luck and Happy Motoring

Respectfully

check the battery in key, check wiring harness to relays behind dash. I think you have a bad relay or connection or button on your key is sticking. Worst case is having shop diagnose system so you can repair.

FORD KEY PADS

• Enter permanent factory code
  
• Press the 1/2 button within 5 seconds to enter programming mode
  
• Within 5 seconds enter new code, doors will lock, unlock to verify code, this erases previous codes remotes will also need to be programmed. (MAYBE)
  

KEY PADS/REMOTES

• Insert key, turn ignition off-to- on eight times in succession, ending with key in on position doors will lock, unlock to verify in programming mode
  
• Press any button on new remote, doors will lock, unlock to verify
  
• Do the previous step with the second remote, doors will lock unlock to verify.
  
• Turn ignition off. Doors will again lock, unlock to verify.
  

NOTE-Some vehicles use 5 turns of the key instead of 8

Check to see if someone might have unplugged the switches or rain may have ruined switch if window was down... the keyless module goes to the relays that throw the actuators. sometimes door switches are wired so one is the master and the other goes through it as a slave. GM should be driver side. also could be broken wires in the door boots from opening and closing. The rear door may have problems with the linkage from the key cylinder to the latch or be rusted. Usually one can find the relays by using the keyless while listening for a light clicking sound under the dash driver side kick panel if you need to check for unplugged harness.

the door lock actuator is defective, they get really hard to move when they go bad, that is why the difficulty with the key.