8975257651 Original Excavator 4HK1 Engine Control Unit for Hitachi

Part number 8975257651 is the original engine control unit (ECU) provided by Hitachi for the 4HK1 series diesel engine. This component is the core electronic module that controls the operation of the engine. Its universal models mainly cover Hitachi medium-sized hydraulic excavators equipped with 4HK1 engines, such as mainstream models in the 20-24 ton range such as ZX200-3, ZX240-3, ZX210LC-3, etc. As the core electronic control unit of the original factory, its hardware interfaces, internal programs are deeply bound to the sensors, actuators, and vehicle CAN bus network of the engine. It is strictly prohibited to use any refurbished, disassembled, or auxiliary parts, otherwise it will cause serious faults such as engine failure to start, torque limitation, black smoke emission, or communication interruption.

This product is an original embedded engine ECU, with a die cast aluminum alloy shell and dense heat dissipation fins, presenting a silver gray metallic texture as shown in the picture, to efficiently dissipate heat and ensure stable operation of internal components in high temperature environments. On the left side, there is an integrated black plastic multi pin harness interface with a locking buckle to ensure reliable connection with the vehicle harness. At the bottom, cylindrical electrical connectors and multiple mounting holes can be seen. Its internal core is a high-performance automotive grade microprocessor with built-in memory that stores all core programs and data such as engine injection MAP, ignition timing, emission control, and fault diagnosis. The working voltage is DC 24V, and the protection level is usually IP67, which can resist the vibration, humidity, and dusty environment of the cab or engine compartment. It communicates with the whole machine monitor through the CAN bus to achieve data exchange and fault alarm.

Replacement and programming: 1 Safe operation: Before replacement, the negative terminal of the battery must be disconnected and wait for at least 5 minutes for the system capacitor to discharge. 2. Swap installation: Disassemble the old ECU and install the new ECU (8975257651) in its original position, ensuring that the wiring harness interface is properly plugged in and locked. 3. Programming is required: After installing a new ECU, it is strictly prohibited to start it directly. It is necessary to use Hitachi's dedicated diagnostic tool to write specific identification information, injector codes, and power calibration data of the original engine into the new ECU. This process is called "ECU matching" or "programming". Unplanned ECU will cause the engine to malfunction. Fault diagnosis: If the engine fails to start, has insufficient power, or the fault light stays on, the diagnostic tool should be connected first to read the fault code in the ECU.