Diagnostic Trouble Code (DTC) Diagnosis

The BCM stores DTCs as current or history DTCs. If the BCM detects a malfunction, the BCM stores a DTC that corresponds to that particular malfunction. The BCM does not send a message to the instrument cluster to display a message, such as turning on a warning indicator lamp. If the BCM stores a current DTC and the malfunction is no longer present, some DTCs will remain current until the next ignition cycle. Other DTCs change from current to history without requiring a new ignition cycle when the fault is no longer present. History DTCs are intermittent malfunctions and must be diagnosed differently than current DTCs.