hello guys and gals...

i have had my xl7 now for about a month i knew when i got it need some tlc but now the trany wont shift in to high gears like 3 or 4th. it would do it some times and other times nothing. any idea what it could be???... speedo works fine my 4x4 does not thou... now for the last week it only shifted once and i have to drive it around only shifting to 2nd any advice i tried to scan and scan port seems to not work using a gennise scan tool and a lunch and nothing my body has this tools at his shop port has power but it keeps saying check conection like it cant read this car ... could this be a sensor prob???

For 2004 + models that would be a safe mode, a computer not liking a signal, or not getting a signal.  If you can't read the codes, it may be a loss of power to one or a part of one of the Control Modules, or one of the sensors.  A missing or broken ground will cause same thing.
Have you worked on anything?