Diagnostic Trouble Codes (DTCs)

The DTCs when set, indicate that the instrument cluster has detected a malfunction in a particular circuit or other system. The instrument cluster is programmed with routines for internal tests that the instrument cluster follows only under prescribed conditions (test conditions). When these conditions exist, the instrument cluster tests certain circuits or systems for a malfunction (failure conditions). When the failure conditions are true, a DTC is set current. Some DTCs command the instrument cluster to illuminate the SERVICE VEHICLE SOON indicator.

The DTCs are not stored in the instrument cluster's electrically erasable programmable read only memory (EEPROM). The DTCs are not retained after a battery disconnect.