You also cannot remote start the car from fob 1 with fob#2 in the car.

I don’t think your question is “dumb.” The key fob (Acura just calls it “the key”) is involved with a number of functions on the RDX, some of which are not obvious, so it is important to know how it works—and the precautions.

You may want to read the “Owner’s Manual” or the “Owner’s Guide” carefully. Pages 148 through 184 of the Manual cover procedures and precautions about the key. There are other places where the key is involved (like the “Driving Position Memory System” on page 201) so you have to do some looking.

Acura does not provide an “Owner’s Manual” at delivery; you have to download it or order a printed copy. The “Owner’s Guide” does come with the car and has a lot, but not all, of the necessary information about the key, scattered throughout.

I’ve driven Acuras with fobs since 2005, and the 2019 has newer features like “walk-away locking” that present new opportunities for me to screw something up. Twice now I’ve left passengers in the car while I run into the store with the key in my pocket, forgetting about the walk-away feature; when they later changed their mind and tried to open the door, the security alarm went off. I just found a procedure to temporarily deactivate walk-away locking on page 153 of the Manual (but I do not see it in the Guide).

I assume from your question that you have enabled the “walk away auto lock” feature (which is “off” by default from the factory).

SHORT ANSWER: I have enabled the auto lock feature, and I sometimes get the “really quick beeps” after walking away—as far as I can tell, it means something is not right, and I need to go back to the car and press the door button or tailgate button to manually lock it. But, I cannot figure out why it happens.

LONG ANSWER: The auto lock sequence is described on pages 152-153 of the Owner’s Manual. The expected sequence is right after you shut the door, a beeper sounds; after you walk more than 5 feet away, “...some exterior lights flash; the beeper sounds; all doors and tailgate will then lock.”

In my experience, I will get the first single beep (which happens when I am still standing by the car after closing the door or tailgate). After I walk 5 feet away, and should hear the sound of the doors locking and a 2nd single beep to confirm, I sometimes get the series of short/rapid beeps instead—no door-locking sound, and no 2nd single beep. In 3 months, I have experienced this only twice when walking away after closing the driver’s door, but about 25% of the time when walking away after closing the tailgate. I am not aware of doing anything differently each time.

I think the short/rapid series of beeps might be the “Auto lock function operation stop beeper” described on page 153 of the Owner’s Manual, which says:
“Auto lock function operation stop beeper. After the auto lock function has been activated, the auto lock operation stop beeper sounds for approximately two seconds in the following cases.
• The keyless access remote is put inside the vehicle through a window.
• You are located too close to the vehicle.
• The keyless access remote is put inside the tailgate. If the warning beeper sounds, check that you are carrying the keyless access remote. Then, open/close a door and confirm the auto lock activation beeper sounds once.”

As far as I know, I have never met those conditions. Also, I could be wrong about the short/rapid beeps being the same as the “auto lock function stop beeper” since I’m not sure that they go for a full two seconds—they just sound like a series of 5 or 6 very quick beeps, maybe one second. There is not much in the OM about “multiple beeps,” and what’s there is not related to locking.

So, I guess I’ve got a question for the dealer, next time I see him.

How far can you walk away while the car is running and the key is in your pocket? I accidentally left it running today and was a good 100ft from the car. Glad the parking lot was empty and nobody stole it lol 😂