GM-50334-12, GM-50334-13 and GM-50334-14 are part of a three piece cable kit that is used in conjunction with each other in order to diagnose various connection points and components of the Next Generation Rear Seat Entertainment module. GM-50334-12 is a male mini B/male mini B USB cable which enables technicians to test for faults in the cable stretching between the splitter and the Media Disc Player. Data comes from the Media Disc Player on 4 of the 5 pins. There is a D+ and D- for screen "A" and D+ and D- for screen "B". Pins 1 and 2 carry the screen A data and pins 4 and 5 carry the screen B data. Pin 3 is used as a "signal shield drain wire". In a normally constructed USB cable, pin 3 would be used to carry data and pin 4 would be the signal shield drain wire. A normally constructed USB cable would not pass the information needed on pin 4 and therefore cannot be used to verify if this cable is faulty.