You have steering wheel controls?
The diagram I gave you includes C125 which is the standard connector. It looks like they've duplicated that with C126, allowing the connection of a different radio when there are steering wheel controls. C126 isn't a 16 pin connector but, rather, about 22 pins, IIRC, although some are not used and there are others that go nowhere.
Your vehicle may be a later build than what is in the manual so it's very likely that yet another "running change" has been implemented, simplifying the connection.
Using the diagram above, check, by wiring colour code, that you have all those wires in the connector, which you can identify. The extra two should be the steering wheel control wires. Most likely that the wire colours haven't changed and you can check these in the diagram at the bottom of the same page in the manual.
With things like this there are often differences and you just have to use the process of elimination. Sometimes you can get lucky and someone like Aerpro have an adaptor harness. On my ML there was an adaptor harness but the positions of the two power wires had been swapped, in the factory, for some unknown reason. It did seem a bit odd that the head unit only worked when the lights were turned on.