How many Coolant Temperature Sensor are in corolla 08?

i saw many video on youtube about ect sensor, some saying it is on thermostat housing and some show near throttle body. some says there are two sensors and some says ther is only one.

can some tell me how many coolant sensor are there actually in car?

what i learned in past is there are two ect, one show the temperature of engine INSIDE and the second show temperature of coolant AFTER passing through radiator.

but as i mention some youtybe video show one sensor and some two. :unsure:


3 Answers

  • Anonymous
    2 months ago
    Favourite answer

    There is only one on your car, it's mounted on the coolant outlet at the rear of the engine.

    Some cars have two, with the second one controlling the electric radiator fan. Your fan is controlled by the computer which uses the same signal as the one for engine control.

  • Geo
    Lv 6
    2 months ago

    You should have 3 total. The one by the Throttle body is the IAT (Intake Air Temp) and one on the Thermostat Housing or Head for the Gauge (CTS) and one for the ECM called the ECT. Some cars incorporate the CTS with the ECT but they're rare. The easy way to tell is that a CTS has 2 Wires, if both CTS/ECT it will have at least 3 Wires. On newer cars the IAT is incorporated into the MAF.

  • 2 months ago

    Thanks for the answer,

    How the ecu know that it is time to turn the fan on and what time to stop?

    Because the sensor is on thermostat  housing and show only outgoing coolant. So how the ecu will know that the outgoing coolant has been cooled by radiator or not?

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