benjmsher wrote:The key fob is difficult to open and using a small screwdriver mars the plastic.
I tried to take mine apart just out of curiosity and had the same experience. I got nowhere using screwdrivers or fingernails. I was
able to open it with a knife blade. I was a bit surprised to see that the battery is installed "upside down", i.e. with the + and battery type information not visible. I would think some people might be tripped up by that, but since you were able to use the fob afterward to open the doors you obviously didn't fall into that trap.
benjmsher wrote:So I tried replacing the spare fob battery first. I did get it to unlock the doors but nothing else. So a few days later I tried my luck with my primary fob and replaced the battery. (And I tested the new battery with my voltmeter and got 3.2 volts vs 2.9 in the weak battery). Car would not turn on. Door unlock would function.
So you have two fobs that work to open the doors, but not to power up the car (except by touching the power button). I don't think this has anything to do with replacing the batteries. It sounds like something wrong with the radio transceiver used inside the car (which is separate from the ones used to communicate with the fobs outside the car). By the way, 2.9v doesn't strike me as terribly weak. Mine is at 3.03v after only five months of use.
benjmsher wrote:But I'm perplexed and annoyed why doing a simple battery replacement in the key fob should result in needing to schedule a service call at the Nissan dealership.
As well you should be if that were true. But it isn't, as many others can attest. Needing a service call for a failing transceiver, though, would be expected. Please tell us what the final resolution of this is.