Speedometer Signal Wire for Pioneer Avic-N2

[hiteksystems]

I Installed the Pioneer Avic-N2 Navigation system in my colorado everthing works, But I'm having problems With the Vss wire. I used the blue connector on the ECM . I tapped into the Yellow/black wire in pin 25. and I get an error message (that says Irregular speed pulse signal detected. please check the installation. after you have checked, please re-boot the system and press ok) when I diconnect the pink wire everything works again. I did notice that before getting the error while looking at the speedometer in the vehicle dynamics display. The the needle Eractic between 0 to 10 mph then it looks like it starts to work fine for a few seconds and the guage says something like this function unavalable the acceleration guage does the same thing. My truck has the auto transmission does anybody know what color is the signal wire that goes to the speedometer in the instrument cluster? Does anybody have a schematic for the instrument cluster or the Ecm showing the VSS Circuit?
Thanks For all the Help