Retrieving Diagnostic Trouble Codes
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
Diagnosis of temperature control portion of HVAC system is based on Diagnostic Trouble Codes (DTCs) stored in HVAC control assembly. The HVAC control assembly will store either a current or history DTC depending on type of fault detected.
For system diagnosis, use a scan tool to check for any DTCs that may be set. If a DTC is set, go to appropriate diagnostic procedure. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table. After a repair is completed, DTCs must be cleared from memory to ensure proper system operation. See CLEARING DIAGNOSTIC TROUBLE CODES . If no DTCs are set, diagnose problem by symptom, see appropriate test procedure under SYMPTOM TESTS .