Its a shiftlight. I use it on my 08 for drag racing. Read the owners book and it will tell you how to set it. You can set it to blink rapidly or stay on constant till you shift,or you can turn it off. You can also change the brightness of it and then ya can change the rpm setting for it to lite up. Here is a run down on how to set it.
Before you turn on the key prees both select and adjust buttons at the same time and then turn on the key.
The mite blink push the adj. button and you can set it to blink stay on or turn it off.
Next hit select and you can set the brightness. At the bottom of the display screen you will see some small ooooo Then push adj. button and this will dim or brighten the light.
Then push sect button , look at the tach. I think it starts at 4000 rpms. Then push adj. button and look at the tach , you will see the needle move. Up to 8000 rpms the needle will move at 500 rpm increments then over that it moves at 250 rpms up to 11,500 rpms.
The owners book has a diagram of the instument panel and a list of everything on it. Read through the book and it does give the instructions on how to set the shiftlight.