DTC U1300, Class 2 Short To Ground: Testing
WARNING: This page is about a different car, the 1997 Cadillac Seville, 1997 Cadillac Eldorado, and 1997 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
DTC U1300 should always be a history code. If DTC U1300 is current, modules on Class 2 serial data line cannot communicate with each other or diagnostic equipment. Check for intermittent short to ground in Purple wire between individual control modules.