Diagnostic Aids

DTC U1000 does not normally identify a module failure. Check fuse supplying power to module with DTC. Check other modules capable of storing serial data DTCs (DTCs beginning with "U") before diagnosing serial data line. Check for DTC U1000 stored in other modules. If DTC is history, problem may be intermittent. Try to recreate fault by wiggling wiring and connectors while performing test.