Electronic Automatic Temperature Control Module - Diagnostic Methods: Notes

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

The electronic automatic temperature control 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 diagnostic tool. If using a diagnostic tool, refer to the diagnostic tool operating manual.

On-demand DTCs can also be retrieved by carrying out the Electronic Automatic Temperature Control Module On-Demand Self Test. To retrieve and/or clear continuous DTCs, carry out the ELECTRONIC AUTOMATIC TEMPERATURE CONTROL MODULE - Retrieve Continuous DTCs . Always carry out the Electronic Automatic Temperature Control Module On-Demand Self Test before retrieving continuous DTCs.

If no DTCs are present, GO to SYMPTOM CHART for the appropriate diagnostic action.