Coolant Temperature Sensor
WARNING: This page is about a different car, the 1995 Cadillac Seville, 1995 Cadillac Eldorado, and 1995 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
The coolant temperature sensor is located in a coolant passage of the intake manifold. Its output is monitored by the PCM, which in turn sends a signal to the ACP for system operation calculations.