JRT600

My father-in-law has a 2006 Silverado, V-6. The speedometer and all the gauges work, but the LED that shows the mileage does not work. I know there is one cable that plugs into the instrument cluster, since on my 2005 Silverado I have had to changed out several of the stepper motors. I am thinking this maybe a connection problem with just the mileage gauge. I am wondering if anyone has had this problem and what they had to do to fix it.
Thanks Travis