Electronically Controlled Hydraulic Cooling Fan System - Toyota 3VZ–FE Troubleshooting Manual

ELECTRONICALLY CONTROLLED HYDRAULIC COOLING FAN
SYSTEM
DESCRIPTION
In this system, the cooling fan ECU controls the hydraulic pressure acting on the hydraulic motor, thus con-
trolling the speed of the cooling fan steplessly in response to the condition of the engine and air condition-
ing.
OPERATION
The hydraulic pump integrated with PS pump is driven by the PS pump drive belt. The solenoid valve ad-
justs the volume of oil sent from the hydraulic pump to the hydraulic motor which drives the fan directly,
thereby controlling the fan speed.
Oil which has passed through the hydraulic motor is cooled by the oil cooler before returning to the PS pump
reservoir tank.
The solenoid valve is controlled by the computer in accordance with the engine rpm, engine coolant temp.
and A/C signals.
ENGINE TROUBLESHOOTING – COOLING SYSTEM
EG–263
EG0A7–01
EG0A8–01