Lost my key can i start my car any other way with spare key that only opens doors

it may not be a spare key !
some cars have a set of keys
one that unlocks the door but does not start the car
one that may unlock the boot but not the car door

You may have a similar extra key !

another one the does every lock

As far as I know there is no bypass for the push button. In my Altima I only have the push button and the key port for the intelligent key to be placed into. There is no manual ignition for the key that unlocks the doors. You're only option is going to be to contact Nissan and have them program you new keys for the car. Sorry I couldn't be more help. Good luck.

Without having a spare key with the chip, its going to be expensive.
A locksmith may be able to make a roadside service call and get it done, but probably not much cheaper than the dealer.

-If your car has key with computer chip. You still be able to open door and trunk with spare key, but can't start the car.
-You can get one and program from lock smith or dealer, but it'll cost 120-180.00 dollars.

you need to get a key made by the dealship and reprogrammed. i had a 999 chrysler lhs in my shop ,and I lost the key,and I had to send to the dealership

Close the doors. Lock the doors using the buttons on the key fob. Use the fob to again unlock the doors. The key should then work the ignition. If this will not work, you will have to tow your vehicle to the dealer and buy a new key and/or fob and have it programmed to the vehicle.

it should be alright as you are only programming the new key not the vehicle ......cheers

Your spare key is not a good key. It is only a slug key. You will have to get a key with a security chip in it and get it programmed to your vehicle.

Key must be made by the dealer and programmed to the vehicle. There is a chip in the key that the antitheft system must read to start the engine. Any key blank with matching cut can open the door, no chip necessary

In some cases, the spare is just a key to get you in the vehicle in case you lock yourself out. The newer model vehicles have a "Chip" in the key and it is "Seen" by the lock. This helps to prevent theft. If you have a key made, you have to go to a dealer to get the info on how to program the new key to get it to start.

Good Luck and hope this helps.