RX7 2RTR-1308cc 1.3L MFI (1991)
Engine - Coolant Temperature Sensor/Switch: Description and Operation
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
