2007 Suburban Tire Pressure reads all dashes

My new 2007 Suburban reads all dashes instead of the actual tire pressure in the DIC.  I went through the learn tire position sequence but it still displays all dashes.  I let some air out and I do get a low pressure warning just not actual pressure numbers bing displayed.  I see there is a service bulletin 060316002 which addresses this issue but I do not have access to these bulletins.

go register your burban at my gmlink.com.  there may be some info there.