History DTCS

When a diagnostic trouble code (DTC) has been set, the instrument panel cluster (IPC) continues to monitor for test conditions and for failure conditions. For most DTCs, if the test conditions are true while the fault conditions are false, the DTC is changed to history. Some DTCs require the test conditions to be true and the fault conditions to be false several times or require an ignition cycle to change from current to history. If there are no current DTCs for a period of 50 ignition cycles, all history DTCs will be cleared.