Toyota 89422-06010 Sensor, Water Temperature

To replace the Coolant Temperature Sensor, start by ensuring the ignition key is in the OFF position. Then, remove the engine covers and drain approximately one gallon of coolant from the cooling system. Next, remove the air filter housing. Disconnect the electrical connector and unscrew the sensor. For four-cylinder models, the ECT sensor is located on the left end of the cylinder head, while for V6 models, it is located on the left end of the engine on the coolant crossover between the cylinder heads. Before installing the new sensor, wrap its threads with Teflon sealing tape to prevent leakage and thread corrosion. Finally, carefully handle the coolant sensor during installation, as damage to it can affect the operation of the entire fuel injection system.

On V6 models, drain the coolant, remove the intake manifold, detach the electrical connector, and loosen the Coolant Temperature Sensor from the crossover to replace the sensor. For V8 models, remove the throttle body cover and air intake duct, and undo the sensor from the coolant crossover. For all models, install a new sealing washer and fill up the cooling system.

On four-cylinder models, the coolant temperature sending unit can be removed by disconnecting the electrical connector and using a deep socket or wrench to remove the unit.

A problem in any of the ECT sensor circuits will set a diagnostic trouble code.

Caution should be exercised as damage to the ECT sensor can impact the functioning of the entire fuel injection system.