Thats the problem there isn't any GR/YL wire in that cluster of wires. I looked when I installed mine and Bluecoupe couldn't find the GR/YL as well.
It wouldn't surprise me if the instructions are wrong because when I first bought my nav radio the instructions that came with the radio were backwards with the wheel speed wire and the back up wire were reversed. I was able to figure it out with the help of a Chrysler tech and Becker of North America. This was before any of the service manuals were available on this forum.