This is not an answer to your question, but it may help you to make some sense of where you are.
I just bought a 2001 Monte LS (yesterday) and it did not come with the FOB and since my 01 Impala has keyless entry, I wanted it on this car.
I called the dealer to see if this car came equipped and the prior owner or dealer just lost (or kept) the remote - they cost about $45 to get them replaced! The dealer (parts department) printed out a list with all of my vehicles original options based on my VIN.
In this list, my car has option AU0 - just like yours., so the guys at the parts counter sold me the remote and told me that I may have to schedule service to have it programmed (that should happen today).
Here's where I will find out if mine is like yours, but with a twist.
The twist - The Impala has a tape player (RDS and factory) and the Monte has a single disk CD player (RDS and factory). Last night I SWAPPED THE RADIOS BETWEEN THE CARS and this sets off the theft deterrent system because the VIN in the radio does not match the VIN in the (current) car - in both cases, obviously.
I plan on taking both cars to the dealer today to have the radios reprogrammed with the correct VIN so I can use them again AND I am also going to have them program the new FOB for the Monte. Now you can see the twist.
As an aside, the thing that bugs me the most is that I prefer to do my own work on my cars, but a guy named John that posts on automotiveforums.com seems to know an incredible amount about the keyless entry system and he said that the Impala/Monte Carlo paltform seems to be one of the few that REQUIRES as scan tool to be connected to the car (costs ~$300?) in order to be able to reprogram the FOBs and to clear out the radios. So you can either buy that unit (is it worth it???) or take it to the dealer. Bummer.
If you reply to this message, then I will repost with what I find out.
Jim