Unfortunately Arnold not entirely supports Maya’s new Color Management System (yet).

This is one way how you render with Arnold in Maya 2016:

Maya’s Color Management System is turned on by default. That’s good.
You can check here:
Windows -> Settings/Preferences -> Preferences -> Color Management

Go to Render Settings -> Arnold Renderer tab -> Gamma Correction:

• Display Driver gamma: 1
• Lights: 1
• Shaders: 1
• Textures: 2.2 (means every (almost – see below) texture used as gamma corrected images)

Nice, but what about the high dynamic range images.
Don’t worry about that. Arnold automatically recognize EXR and other typical linear formats (usually used for image based lighting, as textures on area lights, displacement maps).

Color maps:

Aka diffuse, Specular Color, Reflection Color and others which directly define the surface color. You don’t have to do anything (you already did, when you chose the texture 2.2 in render settings).

Normal and bump maps:

You have to handle this type of maps as linear data (since it is), even it’s sometimes just an 8 bit image and you see them as gamma corrected (when you open it with Photoshop).
Just find the bump2d node, open the Arnold tab and uncheck the Gamma Correct box.
If your normal map looks fliped (i.e. the surface is concave when it should be convex or vice versa) uncheck the Flip G Channel box.

Other linear data type textures:

Roughness, IOR, Reflectance at Normal, Opacity textures and others. Usually you have to correct that types manually (not if the file is an EXR). Just put a Gamma Correct node after the file node. Set the gamma value to 2.2 and connect that to the material.

Arnold trial:
https://www.solidangle.com/arnold/try/

Cheers, D