J'ai fais faire une autre clé de contact qui ouvre les portières

I did make another ignition key that opens doors and puts her but did not start the car. Please.
This is the new key made?That does not start the car but it opens the doors?

Are you able to turn the ignition key?
Is the original key able to start vehicle?
Is the security light flashing in dash?

" Yes the light is flashing on the dashboard of security."

Close all doors and lock them. Use key to open the driver door and try starting. If key flashes, close all door and use key to open passenger door to test.

" Es it possible to weld the old key on the carcass pourque the new key can walk? "

Yes you can. If the key has a transponder embedded in it, hold both keys together to see if it works.

"Have asked to close all doors to a test?

The old key does not have keys for it and how?"

Security system is triggerred and you need to unlock the doors using the key. It can be the passenger door, driver ot the trunk.

Under normal circumstances turning the key in the ignition should reset. Try checking to see if any fuses are blown. I believe your key is not equipped with any transponders and the new key should work by itself.