What is Hitachi ZX890H-5A (HCMC) Fault Code 14105-2?

Fault Code 14105-2 indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically a CAN (Controller Area Network) bus communication error between the engine controller and the machine's main monitoring system. This diagnostic trouble code (DTC) is triggered when the ECM detects an interruption, abnormal signal voltage, or complete loss of data transmission on the CAN communication line.

In the Hitachi ZX890H-5A equipped with the HCMC (Hitachi Construction Machinery Controller) system, this code directly affects the machine's ability to coordinate engine performance with hydraulic functions and monitor critical operating parameters. The CAN bus serves as the digital nervous system, allowing multiple control modules to share real-time data. When communication fails, the machine cannot properly regulate fuel injection timing, power output, or implement safety protocols, potentially leading to reduced productivity and unsafe operating conditions.

Common Symptoms

• Warning lights: Engine warning lamp and/or main monitor display shows fault code 14105-2 with possible "Communication Error" message
• Performance issues: Engine may enter derate mode (limited power output) or experience inconsistent throttle response
• Gauge malfunctions: Intermittent or complete loss of engine parameter readings (RPM, coolant temperature, fuel level) on the main display
• System instability: Unexpected engine shutdown or failure to start, particularly after the machine has been operating
• Hydraulic irregularities: Erratic hydraulic function due to loss of engine-hydraulic system coordination

Potential Causes

The most common technical causes for Code 14105-2 on used ZX890H-5A excavators include:

• Damaged CAN bus wiring harness: Physical damage from rubbing against frame components, especially near the engine mounting points or along the right-hand chassis rail where harness routing is vulnerable
• Corroded or loose connectors: Oxidation on ECM connector pins (particularly the 38-pin main connector) or the HCMC controller connections due to moisture infiltration
• Faulty termination resistors: The 120-ohm terminating resistors at each end of the CAN network may fail, causing signal reflection and data corruption
• ECM internal failure: Less common but possible in high-hour machines; internal circuit board degradation affecting the CAN transceiver chip
• Voltage supply issues: Inadequate or fluctuating power supply to the ECM (should maintain 24V ±2V) due to battery problems, alternator issues, or corroded power distribution connections

How to Troubleshoot and Fix Code 14105-2

Step 1: Visual Inspection and Connector Check Begin by thoroughly inspecting the wiring harness between the engine ECM (located on the right side of the engine) and the main HCMC controller (typically mounted in the cab area). Look for obvious physical damage, chafing, or pinched wires. On used excavators, pay special attention to areas where the harness passes through bulkheads or near moving components. Disconnect and inspect all relevant connectors for corrosion, bent pins, or moisture. Clean connections with electrical contact cleaner and apply dielectric grease before reconnecting.

Step 2: CAN Bus Electrical Testing Using a digital multimeter, measure the resistance between the CAN-High and CAN-Low terminals at the ECM connector with all modules disconnected. You should read approximately 60 ohms if both 120-ohm termination resistors are functioning correctly. Check for proper voltage levels: with the ignition on, CAN-High should read approximately 2.5-3.5V and CAN-Low should read 1.5-2.5V relative to ground. Any significant deviation indicates wiring issues or faulty resistors.

Step 3: Advanced Diagnostics with Factory Software Connect Hitachi Dr.EX diagnostic software or equivalent OEM tool to access detailed CAN bus monitoring. Observe real-time communication status between modules and check for intermittent dropouts. The software can identify which specific module is failing to communicate. For used machines with high operating hours, perform a "wiggle test" by gently moving harnesses while monitoring communication—this often reveals intermittent connection problems caused by worn insulation or loose crimps.

Step 4: Component Replacement and Verification If diagnostics point to a specific component, replace the wiring harness section, ECM, or HCMC controller as needed. When working with used excavators, always verify that replacement ECMs are properly programmed with the correct software version for your machine's configuration. After repairs, clear fault codes, perform a complete system initialization, and run the machine through various operating modes to confirm stable communication.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Hitachi service manual for your specific machine serial number and software version. If you lack proper diagnostic tools or experience with heavy equipment electrical systems, consult a certified Hitachi dealer or qualified heavy equipment technician to avoid further damage or safety hazards.