Check engine lights illuminate when the power train control module on the Ford Windstar detects a malfunction in the power train systems. This malfunction generates a diagnostic trouble code; when the code is stored in memory, the check engine light turns on to alert the driver of the Windstar that a problem exists. Once your retrieve the code, diagnose the problem and repair it, you still need to turn off the light.
Remove the dust cover from the diagnostic port, which is located under the driver side of the dashboard, near the fuse panel. The port is roughly two inches wide by 1/2 inch tall. The dust cover has the letters “DTC” embossed into the face for easy recognition.
Plug the data link cable on your scan tool into the diagnostic port.
Read your scan tool's specific instructions on running a self test on the Windstar. Scan tools vary in operation, design and capability depending on the specific brand and model.
Run the self test once you are familiar with the procedure. When the scan tool prompts you to clear the codes, do so. Complete the self test before disconnecting the data link cable from the Windstar. Reinstall the dust cover on the diagnostic port to make sure no dirt, dust or foreign material enters and contaminates the port.
