TRAVEL DRIVE ASSY. 0995812 - Caterpillar

Illustration 1 g01151249
Block diagram of the operator present system (1) Engine speed sensor (2) Engine Electronic Control Module (ECM) (3) Cat Data Link (4) Parking brake switch (5) Service brake oil pressure switch (6) Transmission output speed sensor (7) Power Train/Chassis Electronic Control Module (ECM) (8) Implement and steering solenoid valve (9) Parking brake solenoid valvesThe operator present function is a function of Power Train/Chassis Electronic Control Module (ECM) (7) . The Power Train/Chassis ECM receives signals from several switches and sensors. The Power Train/Chassis ECM interprets the various input signals. The Power Train/Chassis ECM sends signals to the output components. The operator present function will cause the parking brake to engage, the hoist and steering functions to neutralize and the engine to stop.When the parking brake switch is in the OFF position and the machine is operating, if all of the following conditions are active for greater than 4 seconds, the Power Train/Chassis ECM will engage the parking brake, neutralize the hoist and steering functions and send a signal to the Engine ECM to stop the engine.
Ground speed is less than 5 km/h (3.1 mph)
Service brake control valve released (pedal released)
Engine speed is between 550 and 850 rpmNote: The operator present function engine stop can be configured using Caterpillar Electronic Technician (ET) service tool. When ENABLED the engine will stop. When DISABLED the engine will not stop. Refer to System Operation, Troubleshooting, Testing, and Adjusting, "Configuration".When the parking brake switch is in the OFF position and the operator present function conditions are not active, the Power Train/Chassis ECM will energize parking brake solenoid valves (9) and implement and steering solenoid valve (8) . Pilot oil flows from implement and steering solenoid valve (8) to the hoist and steering pilot circuits. The hoist and steering functions will operate.When the parking brake switch is in the ON position, the machine is stopped and the engine speed is below 1500 rpm the Power Train/Chassis ECM will de-energize parking brake solenoid valves (9) and implement and steering solenoid valve (8) . Pilot oil flow is blocked to the hoist and steering pilot circuits. The hoist and steering functions will not operate.To operate the hoist and steering functions with the parking brake switch in the ON position, raise the engine speed above 1500 rpm. The Power Train/Chassis ECM will energize implement and steering solenoid valve (8) . Pilot oil flows from implement and steering solenoid valve (8) to the hoist and steering pilot circuits. The hoist and steering functions will operate.