Alternate Diagnostic Methods - HVAC Module: Notes
WARNING: This page is about a different car, the 2009 Ford Flex. However, it is still accessible from the selected car via links, so may be relevant.
The HVAC system must be diagnosed by first retrieving any DTCs, if present.
- An on-demand (hard fault) DTC indicates that the fault is currently present. An on-demand DTC suggests a wiring fault, disconnected connector or component failure.
- A continuous (intermittent) DTC alone (corresponding on-demand DTC is not present) indicates that the fault is an intermittent condition and may not be currently present. A continuous only DTC suggests a poor wiring connection, loose pin or terminal, or intermittent component failure.
On-demand (hard fault) or continuous (intermittent fault) DTCs can be retrieved using a scan tool. If using a scan tool, refer to the scan tool operating manual.
On-demand DTCs can also be retrieved by carrying out the HVAC Module On-Demand Self Test. To retrieve and/or clear continuous DTCs, carry out the HVAC Module - Retrieve Continuous DTCs procedure. Always retrieve both on-demand and continuous DTCs before proceeding with diagnosis and/or repair.
If no DTCs are present, GO to SYMPTOM CHART - CLIMATE CONTROL SYSTEMS or GO to SYMPTOM CHART - NVH for the appropriate diagnostic action.