PIN 3J2928 - Caterpillar

Lift Cylinder Head End Pressure Sensor, Lift Cylinder Rod End Pressure Sensor
Illustration 14 g02346299
Lift cylinder pressure sensor locations (22) Lift Cylinder Head End Pressure Sensor located on the small manifold that is mounted on the underside of the non-engine end frame under the sampling ports on the right side of the machine. View: From the machine left side. In front of the articulation hitch looking toward the right side of the non-engine end frame. (23) Lift Cylinder Rod End Pressure Sensor located on the left side of the Implement Control Valve. View: Non-engine end frame access cover removed, on the left side of the Implement Control valve
Illustration 15 g02345979
The Lift Cylinder Head End (HE) Pressure Sensor is a 50 MPa (7252 psi) rated pressure sensor that operates at approximately 500 Hz. The sensor input is used for automatic downshifts in the Auto 1 to 4 Mode. The sensor input is also used when the Aggregate Autodig attachment is installed on the machine or the Payload Control attachment is installed on the machine. The pressure sensor input data is used to determine the force on the work tool when loading in Autodig. The sensor is also used in the machine payload calculation for the Payload Control System.For more information on how the Lift Cylinder Head End (HE) Pressure Sensor is used for control of the Autodig feature, refer to Systems Operation, "Aggregate Autodig" in this manual.The Lift Cylinder Rod End (RE) Pressure Sensor is installed on the machine when the Payload Control System attachment is installed on the machine. The sensor is a 50 MPa (7252 psi) rated pressure sensor that operates at approximately 500 Hz. The input signal data from the RE pressure sensor is used along with the input data from the HE sensor data in the machine payload calculation.For more information on how the Lift Cylinder Rod End (RE) Pressure Sensor is used for control of the Payload Control System, refer to Systems Operation, "Payload System" in this manual.Both pressure sensors receive an operating power supply and ground supply from the Implement ECM 8 VDC power supply.When powered, each pressure sensor will provide a PWM input signal to the Implement ECM. The duty cycle of the PWM input circuit will correlate to a specific oil pressure.A loss of the operating power or ground circuit will cause an above normal input voltage signal due to the ECM pull voltage.The pressure sensor PWM duty cycle range that the Implement ECM will consider as acceptable is 5 percent to 95 percent.The following table indicates the sensor PWM duty cycles at the given oil pressures.
Table 5
Lift Cylinder HE Pressure Sensor and Lift Cylinder RE Pressure Sensor PWM Duty Cycle versus Pressure    
Pressure     Duty Cycle (Percent)     Pressure     Duty Cycle (Percent)    
0 mpa (0 psi)     5     25.6 mpa (4000 psi)     51    
13.8 mpa (2000 psi)     30     31.0 mpa (4500 psi)     61    
17.2 mpa (2500 psi)     36     34.5 mpa (5000