Every camera has extended ISO. In the upper end where the ISO is pushed, I do not recommend using them.
But the extended low ISO is worth testing. In theory, the image quality should be better. The ISO is pulled and the brighter images get darker and that will reduce noise.
Check out the video to see my test on the different Olympus cameras.
This time I am talking about Auto ISO.
The Auto ISO can be found in Custom Menu E in the following Olympus cameras:
Pen E-PL8, E-M5, E-M5 MkII, E-M10, E-M1 and MkII, E-M1,
In Pen E-PL9 and E-M10 MKIII its in the Custom Menu D1
and as shown in the video in E-M1 MkII its in the Custom menu E1.
The Auto ISO can also be set with the Super Panel.
If you havent seen the previous episodes I recomend you to watch them. The whole Using Olympus playlist can be found here: https://goo.gl/9cPqo1
If you have any questions please ask them in the comments!