Amigo 4WD L4-2.3L (4ZD1) (1989)
Engine Temperature Sensor: Description and Operation
Coolant Temperature Sensor
The Coolant Temperature Sensor, located near the carburetor, is a thermistor which relays an engine coolant temperature signal to the ECM.
Temperature changes cause resistance through the sensor to vary, thus creating a signal the ECM can interpret. This signal is used as one of the criteria
to determine when the system is ready to enter closed loop mode. The information is also used to modify the open loop duty cycle.
The temperature/resistance relationship is as follows:
Coolant Temp.
Resistance
15°C (59°F)
4450 +293 or -336 ohms
20°C (68°F)
2100 - 2900 ohms
128°C (262°F)
80 +4.0 or -2.3 ohms