Examination
Location of the coolant temperature sensor on a four-cylinder engine
Location of the coolant temperature sensor on the engine 1 MZ-FE
1. If the temperature gauge does not work, check the fuses in the electrical circuit.
2. If the temperature gauge shows a high temperature when starting a cold engine, disconnect the wire from the temperature sensor (see fig. Location of the coolant temperature sensor on a four-cylinder engine). If the temperature gauge shows a low engine temperature, replace the coolant temperature sensor. If the gauge still shows a high temperature, check the condition of the electrical circuit from the sensor to the gauge, or the coolant temperature gauge itself.
3. If the coolant temperature gauge does not show any temperature after the engine warms up and the fuse is in good condition, disconnect the wire from the temperature sensor and connect it to the vehicle ground. Switch on the ignition for a short time without starting the engine. If the temperature gauge shows a high engine temperature, replace the coolant temperature sensor. If the pointer remains in place, check the condition of the electrical circuit or the serviceability of the coolant temperature gauge.
Replacement
To access the temperature sensor on the 3VZ-FE V6 engine, unscrew the two bolts securing the heat shield and remove it.
1. Drain the coolant from the engine cooling system.
2. Disconnect the electrical connector from the temperature sensor.
3. Unscrew the coolant temperature sensor.
4. Screw in the new sensor and tighten it to the required torque.
Connect the electrical connector to the sensor and fill the engine with coolant.