My deville has lost all power wont turn over wont unlock doors no power whatsoever but its fairly new battery what could it be besides the battery

Take it to an auto electrician to have it checked for operation and reprogrammed with a scan tool computer..

The key will unlock the door using the keyhole and turning the key! This is the fail safe for when there is a flat battery......this does not require any battery power whatsoever! I have used this method with the battery disconnected and locked and unlocked the doors!

battery is goosed get a new one

auto right? there is a neutral/park relay on automatic transmission equipped cars. if it is broken or loose it wont let you to run engine (like you did not place the shifter to N or P position)

also for some US made cars you need to press brake pedal to start car, there is a switch for that you need to find its location on your car.

least possible option. your immobilizer is problematic. it can unlock doors but wont allow it to run engine.

check the fusible link at the large post on the starter. this is the power source for the fuse box, if it goes bad you will lose all power to the car. it will be part of the small wire on the large post, just pull on the wire if the link is bad the wire should pull into.

If it's like mine It's your security system, try unlocking the doors from your keyfob, then start it. It is a security feature to stop people from breaking a window, breaking lock then stealing your car. it will either wait 20 minutes, or you must unlock a door from the keyfob or by using a key in the outside lock, and not by the inside lock button.

try this procedure to reporgram:

1. Close all vehicle doors.

2. Insert the key into the ignition.

3. Hold down the power UNLOCK button on the driver's continue to hold down until instructed
to release in step 9.

4. Perform steps 5 through 8 in fairly rapid succession.

5. Turn the key to the ON position (as far as you can go without starting the engine).

6. Turn the ignition switch to the OFF position.

7. Turn the ignition switch to the ON position.

8. Turn the ignition switch to the OFF position.

9. Release the power unlock button on the door panel. The vehicle will lock and unlock the doors automatically.

10. Hold down the LOCK and UNLOCK buttons on the transmitter simultaneously until the vehicle locks and unlocks.
This step may take up to 30 seconds.

11. Repeat step 10 NOW for each additional transmitter (including any existing transmitters).

12. Turn the ignition switch to the ON position in order to exit the transmitter programming mode

Have the ignition fuses replaced and have the shop that installed the remote start fix the main power sorce for their unit.

I'm sure you've checked, but will the headlights come on? Radio? Any sign of power? Did you check the battery voltage under the hood? Our 2001 was dead. No signs of life at all. I checked the voltage and was approx 3.5V on new battery. I pulled the back seat and measure straigt off the battery. 11.89V. Believe it or not, had loose connection for no rhyme or reason. Tighted battery connections and we're back on the road. Just a thought.......

I had this problem and in the trunk on the driver side pull the inner panels down. There should be a little box and a 2 prong plug beside it. You need to bridge the 2 prongs on the plug over and the doors will lock then unlock. After they do then use the lock button on your remote and this should fix the problem. Good Luck