Can't get key fob to work. Replaced the battery in key fob but now can't get it to start. Used the "inside" key, & it cranks, but won't turn over. With key fob it seems to be "locked"

It sounds like the battery is not a fresh one.. You may need an auto electrician to check programming.

NTSB Service Bulletin from Nissan

Nissan; Remote Engine Start Not Working

National Highway Traffic Safety Administration (.gov)
https://static.nhtsa.gov > odi > tsbs > 2019
PDF Aug 13, 2019 - If the above conditions are met, RES should work. 1. Point the Intelligent Key at the vehicle. 2. Press the LOCK button. 3. Press and hold the ...

https://www.google.com/search?q=2019+nissan+rogue+remote+start+not+working

..

Try this

To fix the Dodge Nitro anti-theft mechanism, you will insert the ignition key and turn it to the on spot, and then attempt to start the engine (crank over), the engine does not run. With the key still in the run spot, wait 10 minutes, and the safety light will flash and then go out.

How do i reset the Dodge Nitro anti theft? - Vehicle History

Or this

How do I reset my Dodge anti-theft system?
To deactivate the anti-theft system so that you can drive your vehicle normally once again, the steps are simple:

1. Place your key in the ignition of the vehicle.
2. Do not attempt to crank up your truck.
3. Allow your key to sit in the ignition for 60 seconds. ...
4. After 60 seconds have passed, start your vehicle as normal.

Jun 28, 2021

Dodge Ram 1500: Resetting the Anti Theft - VehicleHistory

Change. The battery and see if it works. You use the remote all the time it will drain the battery faster

The fob would need to be reset to the car computer - check your owners manual. On some models you press both keys at the same time.

Try not using the fob at all open the door with the key. And start the jeep if it works without issue then its the fob. If its still not working correctly remove the battery from the fob and try again(since if it was damaged could be sending the signal for the panic button) the next step is the key try your spare security key can become worn and cause issues with the antitheft system. After that it only leaves computer problems and those can get spendy

start by replacing battery in key fob

You most likely have an aftermarket fob and remote start unit.What is the brand on the back of your key fob?You will have to get the proper reset and registration procedures for the particular unit installed in your car to make your key work normally.

First thing, does the red light on the remote light up when you push any of the button
if no, then replace battery inside remote
if yes, then try repograming the remote to the car again.
-Have both remote ready. fob#1 and fob#2 (doesn't matter which one is #1 or #2)
-each step has to be done within 5 sec or it will not work, but don't do it super fast.
1.turn key just to the "on" position (not starting) and push "lock button " on fob#1 once and release
2.turn key off
3.turn key just to the "on" position (not starting)and push "lock button " on fob#1 once and release
4.turn key off
5.turn key just to the "on" position (not starting)and push "lock button " on fob#1 once and release
6turn key off
7.turn key just to the "on" position (not starting) and push "lock button " on fob#1 twice (if you only have one fob, then stop here and go to step 7)and push the "lock button" on fob#2 twice.
8.turn key off and remove key from ignition.
if you did it right, remotes should work again.
good luck

What year(s)?