HOSE AS 3307736 - Caterpillar

Illustration 1 g00889050
Electronic Control Module (Power Train/Chassis)
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Location of the Power Train/Chassis Electronic Control Module
The Power Train/Chassis Electronic Control Module (Power Train/Chassis ECM) is the main component in the brake electrical system. The Power Train/Chassis ECM is located behind the cover at the front of the cab. The Power Train/Chassis ECM has several input signals and output signals. Refer to the illustration on the previous page for the input signals and for the output signals.The Power Train/Chassis ECM receives current through a circuit breaker on the dash panel. This current is used to energize the retarder solenoids and the parking brake solenoids. These solenoids control the application of the retarder brake system, the Automatic Retarder Control (ARC) system, and the parking brake system. The Power Train/Chassis ECM receives information from various input components. The Power Train/Chassis ECM uses this information in order to determine if the retarder brakes should be applied or if the parking brake should be engaged. The output components are then activated in order to apply the brakes. The Power Train/Chassis ECM also controls the electrical system for the power train and for the hoist hydraulic system.The Cat Data Link is used to share information with other systems such as the Engine Electronic Control Module (Engine ECM), and the Caterpillar Monitoring System.Brake Application
The Power Train/Chassis ECM uses the input signal from the parking brake switch in order to energize the parking brake solenoid valves. If the parking brake switch is in the ON position, the parking brake solenoid valves will be de-energized. Parking brake oil will be returned to the hydraulic tank and the springs in the wheel brakes will engage the parking brake. If the parking brake switch is in the OFF position, the parking brake solenoid valves will be energized. Oil will be permitted to flow through the parking brake control valve to disengage the parking brake.When it is necessary to retard the machine, the Power Train/Chassis ECM will energize the retarder supply solenoid valves and the retarder control solenoid valves. If the ARC is not needed and the retarder lever is in the OFF position, the supply solenoid valves will not be energized. The control solenoid valves will not have any oil supply. The supply solenoid valves will be energized if the ARC is turned on and the engine speed is within 50 rpm of the programmed setting, or if the retarder lever is being used. The retarder control solenoids are a proportional type solenoid. Either the required level of braking or the position of the retarder lever will determine the amount of current that is supplied in order to open the control solenoid valves. When more current is supplied to the control solenoids, the control solenoid valves will open further.Automatic Retarder Control
The Automatic Retarder Control (ARC) is designed to modulate the service brakes of the machine during the descent of a long grade. The ARC modulates the service brakes in order to maintain a constant engine speed. A constant engine speed improves