Hitachi ZX870H-3 Fault Code 14106-2: Complete Diagnostic Guide

What is Hitachi ZX870H-3 Fault Code 14106-2?

Fault Code 14106-2 indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically a data link error or CAN bus communication failure between the engine controller and other machine systems. This code is part of Hitachi's proprietary diagnostic system for the ZX870H-3 excavator series.

This fault affects the Controller Area Network (CAN) communication protocol that allows the ECM to exchange critical data with the hydraulic controller, monitor display, and other electronic control units. When communication breaks down, the machine cannot properly coordinate engine performance with hydraulic demands, potentially causing operational inefficiencies and safety concerns. For a machine of this size and complexity, maintaining reliable ECM communication is essential for optimal fuel efficiency and preventing costly component damage.

Common Symptoms

• Warning lights illuminated on the operator display, often accompanied by a "Check Engine" or communication error message
• Reduced engine power or derate mode activation, limiting machine performance to protect components
• Erratic gauge readings or complete loss of display information (RPM, temperature, pressure readings)
• Intermittent loss of hydraulic responsiveness due to disrupted coordination between engine and hydraulic systems
• Difficulty starting or unexpected engine shutdowns during operation

Potential Causes

The most common technical causes for Code 14106-2 on used ZX870H-3 excavators include:

• Damaged or corroded CAN bus wiring harness, particularly at known rub points near the engine mounting brackets and along the boom base
• Loose or corroded connector pins at the ECM or junction box connections, especially after years of vibration exposure
• Failed termination resistors on the CAN bus network (typically 120-ohm resistors at network endpoints)
• ECM internal failure or corrupted software/firmware requiring reprogramming
• Voltage supply issues to the ECM caused by failing alternator, weak batteries, or poor ground connections
• Water intrusion into harness connectors from damaged seals or improper maintenance

How to Troubleshoot and Fix Code 14106-2

Step 1: Visual Inspection Begin with a thorough physical examination of all wiring harnesses between the ECM and main junction boxes. On used excavators, check specifically for harness wear at pivot points, melted insulation, or green corrosion on connector pins. Disconnect and inspect each CAN bus connector, cleaning contacts with electrical contact cleaner.

Step 2: Electrical Testing Using a digital multimeter, verify proper voltage supply to the ECM (typically 24V on this model). Check CAN High and CAN Low circuit resistance between network endpoints—you should measure approximately 60 ohms with the system powered off, indicating proper termination resistors. Test for short circuits to ground on both CAN lines.

Step 3: Advanced Diagnostics Connect Hitachi Dr.EX diagnostic software or compatible scan tool to read live data and freeze frame information. Monitor CAN bus activity and check for intermittent dropouts. Verify ECM software version and update if outdated firmware is detected. If all wiring tests pass, the ECM itself may require replacement or professional reprogramming.

Critical for Used Equipment: Before replacing expensive components, thoroughly inspect all harness routing for modifications made by previous owners and check for aftermarket accessories that may have compromised the CAN network integrity.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Hitachi service manual for your specific machine serial number and consider professional assistance for complex electrical diagnostics.