Very interesting.
Set the light for 2k and try the experiment again. @5K, there's going to be some natural strain/resistance from the engine. The instant you back off the throttle, the AT's going to upshift. But @2K, there's no resistance; the engine will very freely rev above 2K and it should be
very easy to tell that it's actually limiting revs. Put it in Manual mode, floor it. If it actually holds you at ~2K without shifting, then it's a bona fide rev limiter. Neat.
In my 6MT, the setting triggers the light. Nothing more, nothing less. It
does not actually limit the RPM range. I can set my light for 2K and wind it out to 7k+ RPM. Makes zero difference to the operation of the engine. The owner's manual makes no indication that it should actually affect engine performance, either for an AT (5-15) or MT (5-19).
And other than the 4k RPM limit suggestion during break-in, why would this shift-limit feature actually be useful? Can't you just use your right foot to control the shift point? The AT will do what every AT does and automatically react to the throttle input. What purpose does it serve to be able to set an arbitrarily low limit? I mean, it's like a self-imposed limp-mode. I get it that it's an interesting feature, just curious why you'd ever really use it.
You crazy AT drivers.
