DTC P0217: ECT Sensor Circuit Over Temperature: Description
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The Coolant Temperature telltale on the Instrument Panel (IP) has the ability to illuminate as a result of an engine overtemperature condition. The ECM will send a message to the IP cluster over the Class II link to turn the coolant temperature telltale ON if the Engine Coolant Temperature (ECT) exceeds the temperature calibration value listed under DTC parameters. The coolant temperature gauge will read approximately 7/8 of the way toward HOT when the telltale is turned ON.