Self-Diagnostics - HVAC System - Automatic

The heater and A/C programmer contains a set of self diagnostic tests. When you use a scan tool, the diagnostic tests will identify the source of any system malfunction as specifically as possible. The scan tool also tells you whether the malfunction is current or non-current (history). Refer to DTC Table for a diagnosis of the HVAC DTCs which the PCM sets. Diagnostic Trouble Code Descriptions