A Honda motor Odyssey 2.4L car with a mileage of about 98 thousand km is equipped with the K24A6 engine in 2008. The engine of the vehicle appeared overheating, and then the engine was powerless. Fault diagnosis: 1) first check that there is no leakage in the cooling system, and the coolant is also between the upper and lower limits. 2) use HDS to read the engine trouble code to show that everything is normal. 3) when the engine is overheated, the cooling fan is not at high speed, indicating that the fan control system or cooling system has failed. 4) using HDS to read the temperature sensor 1 of the engine coolant, the temperature is higher than 96.5, and the temperature sensor 2 is 85, indicating that the difference between the readings between the two temperature sensors is relatively large, which is the failure of the cooling cycle system. 5) loosening the assembly bolts of the pump pulley and removing the water pump pulley, and when rotating the pump counterclockwise, it is found that the rotation is not flexible, indicating the internal fault of the pump. 6) discharge the engine coolant and then dismantle the pump and find that the interior has been rusted. 7) replace the thermostat while replacing the pump, then add Honda special antifreeze and emptying operation. 8) start the engine and read the data flow of the two sensor after the engine reaches the normal temperature. The difference is 2 degrees, which indicates that the coolant is in normal circulation. 9) when the temperature reaches 105 degrees C, it is found that the cooling fan runs at high speed and the overheating fault is eliminated. Maintenance summary: when replacing or adding coolant, it is necessary to use Honda special coolant to prevent premature damage in the cooling system.