With Scan Tool

The DTCs in the HVAC programmer are erased in one of two ways:
1. Tech 1 "Clear DTCs" selection.
2. Ignition cycle default.

TECH 1 METHOD
Select F2 for diagnostic trouble codes. After DTCs have been viewed completely, Tech 1 will ask, "CLEAR DTCs"?; answer "YES." Tech 1 will then read, "HISTORY DATA WILL BE LOST. CLEAR DTCs"? Answer "YES." and the DTCs will be cleared.