Are you switching the display?
I have mine normally set on the display that shows average MPG and miles driven on the tank. Once the wrench illuminates, you have to "switch" it to a different screen, and then back to get it to go off.
If you've done this and it remains illuminated, then something is wrong with your maintenance minder.
And of course, even if you switch it, and turn it off...it will re-illuminate next time you start the vehicle.

 

Ya it would be nice if it went away after a while, but it won't unless you switch the display by hitting the knob. After the 15% comes on, I'll just find a convenient weekend or day off to do the oil change. I don't really stress about it.

On my 4runner the maintenance reminder will blink about 10x when starting up then go away as a warning. When it gets really close to the maintenance time, it will stay lit completely. They use an old system of every 5k OCI.

 

Fitchet -
Yes I do change the display, but it does reappear.

 

Annoying....
It should go away, until you turn the vehicle off and restart it the next time. So, I'd say your Maintenance Minder has a glitch.