2001 Lexus RX300 Key FOB replacement question

The remote access key for my Lexus RX300 (2001) doesn’t work any more. I thought the battery may be dead. Replaced the battery with new one, yet it doesn’t do anything remotely, like closing or opening door. Took it to my mechanic and he checked with a gadget and said there is no signal from the key.

What are my options now? First option (expensive) is to go to the local dealer. I would like to explore if there is inexepnsive alternative, hence I positing the question in this forum.
I am confused with statements like …

DIY Step by step programming instructions included -
1 working original key required to add a new key with the DIY procedure (Key blade will need to be cut prior to programming)

Since my key is totally dead and not transmiting any signal, this is not a viable option, am I right?
My mechanic said, buy on-line and bring the key to me and I can program it. So I am tending towards that option. In that case what kind of key I should purchase? What does

  • Replacement for P/N: N14TMTX-1 mean? Will this work for me?

Thanks in advance.

Arun

It is probably a newer version.
why not ask your mechanic to order you the key?
Or you can try going to a professional locksmith to get a new key. most can even program them but would need the vehicle there to do that part.

I ordered new fobs on line that were exact replacements. The dealer though had to program them. I paid somewhere around $100 for the two fobs and the dealer charged $120 for programing. They do wear out. Your results may be vary.

The confusing instructions you are encountering may be related to anti-theft restrictions associated with key repair/replacement that wouldn’t be a problem, for example , if you were just replacing the car’s water pump.