Hard Diagnostic Trouble Code (DTC)

HARD DIAGNOSTIC TROUBLE CODE (DTC)
Any Diagnostic Trouble Code (DTC) that is set whenever the system or component is monitored is a hard DTC. This means that the problem is there overly time the TCM or TCCM checks that system or component. Some DTCs will set immediately at stall. up and others will require a road test under specific conditions. It must be determined if a DTC is repeatable (Hard) or intermittent before attempting diagnosis.