TUBE AS 1345135 - Caterpillar

Input Signals
Illustration 1 g06183893
Fan Control System
(1) Machine ECM
(2) ATAAC air temperature sensor
(3) Hydraulic oil temperature sensor
(4) Engine coolant temperature sensor
(5) Fan solenoid
(6) Engine ECMNote: The blue lines (sensors) in the illustration indicate an input signal. The red lines (solenoid) indicate an output signal. The red and blue lines indicate two-way communication. Arrowheads indicate the direction of communication.Note: The illustration shows the general layout of the propel control system. Refer to the machine electrical schematic for detailed wiring information.Machine ECM (1) determines the required fan speed. The ECM uses input signals from the following components to calculate the required fan speed:
ATAAC (Air-To-Air After Cooler) air temperature sensor (2)
Hydraulic oil temperature sensor (3)
Engine coolant temperature sensor (4)Note: Engine ECM (6) monitors engine coolant temperature sensor (4), and sends the signal to machine ECM (1) through the CAN lines.Output Signals
Machine ECM (1) sends the required fan speed signal to engine ECM (6) over CAN lines. The engine ECM then sends the proper output signal to fan solenoid (5).Engine ECM (6) proportionally controls fan solenoid (5). The amount of current sent to the fan solenoid is inversely proportional to the speed of the fan. A low current signal to the solenoid produces a higher fan speed. A high current signal to the solenoid produces a lower fan speed.