PT Cruiser L4-2.4L Turbo (2009)
Engine - Coolant Temperature Sensor/Switch: Description and Operation
Engine Coolant Temperature Sensor - Description
2.0L/2.4L ENGINE
The engine coolant temperature (ECT) sensor (1) threads into the thermostat housing just below the coolant outlet connector. New sensors have sealant
applied to the threads.
The ECT Sensor (2) is a Negative Thermal Coefficient (NTC) Sensor. The resistance of the ECT Sensor changes as coolant temperature changes. This
results in different input voltages to the PCM. The PCM also uses the ECT Sensor input to operate the radiator cooling fan(s), and send a message over
the PCI bus to the instrument cluster for temperature gauge operation.