If you're trying to get hands-free calling working the XL series doesn't support it, only the higher-end 7xx and 9xx models do.
The Bluetooth functionality in the XL is for Bluetooth data as part of the TomTom Plus services, including weather and traffic.
http://www.tomtom.com/plus/
I have a tom tom One XL.s and wondering how to get the blue tooth working?

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