Diagnostic Aids
WARNING: This page is about a different car, the 2000 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
DTC U1300 cannot be retrieved as current. If DTC U1300 is set, test class 2 serial data line. See SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SELF-DIAGNOSTIC SYSTEM. An intermittent condition can be caused by short to ground on class 2 serial data line.