The position distribution of high and low pressure sensors of Kobelco excavators and related troubleshooting methods

In the daily operation of excavators, various alarm codes are always encountered. The excavator moves slowly and weakly, often showing alarm codes starting with the letter B. These are all faults of the low-voltage sensor. If an alarm code starting with the letter C appears, it indicates a fault of the high-voltage sensor. How to find these sensors and eliminate the faults? Let's explain it in detail for you today.

Troubleshooting methods for alarm codes starting with B and C

Swap the faulty low-voltage sensor/high-voltage sensor with other low-voltage sensors/high-voltage sensors. If the original code disappears and other alarm codes appear, it indicates that the sensor is broken and can be replaced.

After replacing the sensor, the alarm still persists. It is necessary to check and handle it according to the wiring guidelines.

If there are no issues with the above checks, it indicates that the computer board is faulty. Replace the computer board and then confirm whether the alarm has disappeared.

The function of low-pressure sensors

After the operation handle is fully formed and pulled, it outputs the pilot pressure oil twice. While being sensed by the low-pressure sensor, it reaches the valve core of the multi-way valve. The low-pressure sensor detects the pilot pressure of the operation handle and sends an electronic signal to the electromechanical controller (CPU) for calculation. The calculation result is then sent to the hydraulic pump regulator, and the inclination Angle of the swash plate of the hydraulic pump changes. The output flow of the hydraulic pump changes accordingly. The electromechanical controller senses the driver's hand movements through the signals from the low-voltage sensor and then performs corresponding operations.

01. Position distribution of SK75 low-pressure sensor

02. Position distribution of low-pressure sensors ranging from 10 to 40 tons

Note: All low-pressure sensors of the same model can be interchanged and used with each other.

The function of high-voltage sensors

In electromechanical control, high-pressure sensors are used for pump flow control, engine horsepower control, combined flow control, etc.

The excavator has two high-pressure sensors, namely the P1-side high-pressure sensor and the P2-side high-pressure sensor, which are respectively located on the P1 pump and P2 pump of the hydraulic pump.

01. Position distribution of SK130/140 high-voltage sensors

02. Position distribution of 20-30 ton class high-pressure sensors

03. Position distribution of 40-ton high-pressure sensors

Note: Two high-voltage sensors of the same model can be interchanged and used with each other.

PS: The Kobelco SK60 excavator does not have a high-pressure sensor or a low-pressure sensor.

If the signals from the low-voltage sensor or the high-voltage sensor are interrupted, the electromechanical controller will immediately become unable to make status judgments, which will affect the related action operations and speed. Therefore, when a malfunction occurs, it is recommended to promptly investigate and solve it.