With Scan Tool

Current diagnostic trouble codes can be read by using the scan tool diagnostic computer. The presence of history diagnostic trouble codes can be determined by using "Flash Code" diagnostics, however, the specific history diagnostic trouble code numbers must be read and cleared by using scan tool diagnostics.

History diagnostic trouble codes can only be cleared by using scan tool diagnostics. If a scan tool is not available, inform the owner of the information stored in the history record and suggest it be cleared upon the next visit to a GM dealership.