SYSTEM / Control System Fan Pump Flow Rate Control Purpose: Controls delivery flow rate of the fan pump according to boost temperature, coolant temperature, hydraulic oil temperature and intake air temperature.Controls deliver flow rate of the fan pump in order not to decrease although engine speed is slow with the air conditioner ON. Therefore, controls fan rota- tion speed in order to make temperature of oil cooler, radiator and intercooler appropri- ate. Operation: Blower Motor Relay (Air Conditioner Switch): OFF 1. The signals from boost temperature sensor and coolant temperature sensor are sent to MC via ECM and CAN. 2. The signal from hydraulic oil temperature sensor is sent to MC. 3.
MC calculates fan rotation speed according to each signal. 4. MC sends the fastest value of fan rotation speed to the fan pump control solenoid valve and con- trols delivery flow rate of the fan pump. 5. Consequently, fan rotation speed is controlled properly. Blower Motor Relay (Air Conditioner Switch): ON 1. The signals from boost temperature sensor, coolant temperature sensor and in-take air tem- perature sensor are sent to MC via ECM and CAN. 2. The signal from hydraulic oil temperature sensor is sent to MC. 3. The signal of target engine speed from engine control dial is sent to MC. 4. MC calculates fan rotation speed according to each signal. 5.
MC sends the fastest value of fan rotation speed to the fan pump control solenoid valve and con- trols delivery flow rate of the fan pump 6. Consequently, fan rotation speed is controlled properly regardless with engine speed. T2-2-38