SEAL 2J2631 - Caterpillar

Illustration 1 g03114601
Components that are used for the electronic control of the primary steering system and the secondary steering systemThe 966K XE Wheel Loader features an electrohydraulic (EH) Primary Steering System. An EH Secondary Steering System can be installed on the machine that will provide backup steering control if a primary system component fails.The Implement ECM monitors and controls the operation of the Primary Steering System. If the Implement ECM detects abnormal operation, the ECM will instruct the Machine ECM to activate and control the operation of the Secondary Steering System.Note: When flashing the Implement ECM using the J1939 CAN communication system, the Implement ECM will display as the "Body Control". Select the "Body Control" when flashing software to a new ECM that will be used as the Implement ECM. Also, select the "Body Control" when updating the software on an existing Implement ECM.An attachment is available that includes an electric secondary steering pump motor that can be used as a backup pump. The secondary pump is activated when operation of the primary steering hydraulic pump is not available. The operation of the secondary steering pump motor is controlled by the Machine ECM.The standard machine configuration consists of separate sets of electronic proportional steering solenoid valves. The two primary steering solenoids are controlled by the Implement ECM. The two redundant steering solenoids are controlled by the Machine ECM.Both of the control modules monitor the input signals from the main steering system input devices. The shared input information and the separate sets of solenoid valves allow for closed loop command and feedback control of the active steering system.The steering system is controlled according to operator input sent to the ECM by the Transmission and Steering Control, also referred to as left joystick. The joystick is mounted on the left console in the cab. An optional steering wheel with transmission control is also available.Three internal position sensors send signals to each ECM indicating the position of the left joystick or optional steering wheel on the left-right steering axis. The ECM will send current commands to the proportional solenoid valves based on the position of the joystick or optional steering wheel. These commands are also based on the articulation steering cylinder position that is monitored by each ECM.The left joystick or optional steering wheel features an internal electric motor that is electronically controlled by the Implement ECM. This motor provides a resistive force feedback to joystick or optional steering wheel movement. This force feedback is used to dampen and stabilize the movement of the joystick or optional steering wheel.For detailed information on the operation and control of the Primary Steering System, refer to the Systems Operation, "Steering System (Electrical)" section of this manual.For detailed information on the two configurations for the operation and control of the Secondary Steering System, refer to the Systems Operation, "Secondary Steering System (Electrical)" section of this manual.