Turbo

The Water Thermosensor, located on top of the engine near the thermostat housing, is a thermistor device whose resistance varies with changes in engine coolant temperature. The ECU sends a reference voltage to the sensor and measures changes in resistance as engine temperature fluctuates. The ECU utilizes this engine temperature information in its calculations for outputs such as air/fuel ratio control and emission devices.

Sensor temperature/resistance relationship is as follows:

COOLANT TEMP. RESISTANCE (K OHMS)

-20°C (-4°F) 16.2 ± 1.6
20°C (68°F) 2.5 ± 0.2
80°C (176°F) 0.3 ± 0.1