ENGINE AR 9Y8245 - Caterpillar

Illustration 1 g03586556
Schematic of the Machine Electric Control Module (ECM) Output Components
(1) Machine ECM
(2) Front supply solenoid valve
(3) Rear supply solenoid valve
(4) Monitoring system
(5) Front control solenoid valve
(6) Rear control solenoid valve
(7) Engine overspeed control indicator Machine Electric Control Module
Machine ECM (1) controls all machine system features. A general description of each machine feature is listed below.Solenoid Valves
Solenoid valves include:
Supply solenoid valves (2) and (3)
Control solenoid valves (5) and (6)Brake Control Solenoid Valves
Illustration 2 g03586559
Location of brake control solenoid valves
Illustration 3 g03586560
(2) Front supply solenoid valve
(3) Rear supply solenoid valve
(5) Front control solenoid valve
(6) Rear control solenoid valve Solenoid valves are used to control the operation of the engine overspeed function. The solenoid valves are connected to Machine ECM (1). Machine ECM (1) will use Pulse Width Modulated (PWM) driver circuits to energize the solenoids.The engine overspeed control system uses four solenoid valves. Solenoid valves (2), (3), (5) and (6) are outputs of Machine ECM (1). Supply solenoid valves (2) and (3) are energized to allow oil to flow from the brake accumulator to control solenoid valves (5) and (6). Control solenoid valves (5) and (6) are energized to allow oil to flow to the service brakes. Applying the service brakes will prevent engine overspeed.Solenoid valves (2), (3), (5) and (6) have a connector with two contacts.Front supply solenoid valve (2) connector contact 1 receives power from the connector contact (J1-48) of Machine ECM (1). Front supply solenoid valve (2) connector contact 2 returns to connector contact (J1-50). Rear supply solenoid valve (3) connector contact 1 receives power from the connector contact (J1-49) of Machine ECM (1). Rear supply solenoid valve (3) connector contact 2 returns to connector contact (J1-50).Front control solenoid valve (5) connector contact 1 receives power from the connector contact (J1-51) of Machine ECM (1). Front control solenoid valve (5) connector contact 2 returns to connector contact (J1-50). Rear control solenoid valve (6) connector contact 1 receives power from the connector contact (J1-52) of Machine ECM (1). Rear control solenoid valve (3) connector contact 2 returns to connector contact (J1-50).Machine ECM (1) will energize each solenoid when the engine overspeed control is activated. Engine overspeed indicator (7) on the indicator lamp panel will illuminate when the engine overspeed control is activated.