Q: how to activate message access profile

Your phone supports MAP...there is nothing for you to turn on/off. Try re-pairing your phone.

MAP is an available bluetooth profile with the iPhone 4 and later. This should be activated and available when Bluetooth is enabled. There is not a separate setting for this on the iPhone.

http://support.apple.com/kb/HT3647?viewlocale=en_US&locale=en_US

Why doesn't it work with Uconnect?

Ask your dealer.

Finally iPhone 5, iOS 6.1.4 does it support MAP profile or we need IOS 7 to have MAP profile available?

iOS 7 Handfree message setup

1. Pair your phone with the vehicle using the proper steps for individual vehicle.
2. In you iPhone open settings
3. Open Bluetooth connections
4. Locate the head unit device. This is located below the Bluetooth on/off slider. A standard name may be Car Multimedia, locate your head unit name. There will be a button off to the right shaped like a lower case i with a circle around it, tap that and it will open up settings for the device/vehicle.
5. Turn on "Show Notifications"
6. Go back to home screen and turn phone off then turn it back on.
7. While your vehicle is still on and your phone completely boots up they should connect automatically and the text messages should start coming through your vehicle as long as it's turned on in the vehicle settings.

iPhone 4, 4s, 5, 5c, 5s support MAP and a whole lot of other systems.

Anything before iphone 4 is missing MAP and I doubt will ever have it.

That worked!  Thanks Mjdau. 

Tried this on my MDX 2015.

It does not give me the option to select text/email account.

TRy the advice from Mjdau.  It worked for me.

I did get text but no email.

Also the preset reply thru the Acura MDX system does not seem to work

Hello Raymond, I don't have an Acura, and my car does not claim to offer access to emails, only text messages.  I was happy to find out about texts, but emails would be great.

John

thanks for actually ANSWERING the question and being thorough, unlike many of the other responses.  well done!