Coolant Temperature Sensor (CTS)
WARNING: This page is about a different car, the 1996 Saab 9000. However, it is still accessible from the selected car via links, so may be relevant.
The CTS is located on the intake manifold flange. It transmits an engine temperature signal to the fuel injection ECM. If the ECM fails to receive this signal, it defaults to an assumed engine temperature of 113°F (45°C).