Komatsu D375A-5 Steering Potentiometer Adjustment (1)

Palm Command Control System D375A-5

Palm Command Control System (PCCS) is the system in Komatsu Buldozer D375A-5 to control the machine directional, transmission gear speed and steering. It consist of 4 potentiometers and 2 switches. 2 potentiometers for steering signal (left or right steering and 2 potentiometers for directional signal (forward, neutral or reverse). 2 switches are NO/NC (Normaly Open/Normaly Close) type switch, one for shift up switch and the other for shift down switch.

The steering potentiometers have 3 wire system. Those are power (+5V), signal and ground. All of the cables are connected to the Steering Controller.The signal from the steering potentiometers are used to determine the RH & LH Steering Pressure and also RH & LH Brake pressure by regulating the steering and brake ecmv proportional solenoid current. When the steering lever (PCCS lever) is neutral, the voltage signal from each steering potentiometers are 2500 mv +/- 50 mv.

The Directional potentiometers have 3 wire system. Those are Power (+5V), Signal and Ground. All of cables are connected to the Transmission Controller. The signal from directional potentiometers are used to determine the directional of transmission, Forward, Neutral or Reverse. When the PCCS lever neutral, the voltage signal from each directional potentiometer are 2500 +/- 50 mv.