I just bought an '08 G35. One of the FOBs is not working, I changed the battery in it and still none of the buttons do anything. When I put it in the slot in the dash the car does not recognize it. How can I know if the FOB is toast or if it just needs to be synced with the car? The battery in the car was replaced before I picked it up. Could that have an effect on whether the car recognizes the FOB? The other FOB works fine but if it goes I have no way to start the car!

 

Changing the vehicle battery does not affect BCM programming. Take it to your local Nissan dealership, chances are your fob died.

 

Had a locksmith provide an OEM FOB and program it all for $165. I feel better. I asked what he charges just to program and he said he will not program FOB's that are bought on Ebay or other sites. He has had situations where the knock-off FOB messed up the computer in the vehicle weeks after he programmed it. Not worth the risk to buy a $20 FOB. Just bite the bullet and get it done right.