What is Hitachi ZX360H-5G Fault Code 14105-2?

Fault Code 14105-2 indicates a "Fuel Injection Control System - Injector Circuit Malfunction (Cylinder 2)" on the Hitachi ZX360H-5G excavator. This diagnostic trouble code (DTC) signals that the Engine Control Module (ECM) has detected an abnormal electrical signal or performance issue within the fuel injector circuit for the second cylinder of the Isuzu engine powering this machine.

This code specifically relates to the common rail fuel injection system, where the ECM monitors injector solenoid resistance, voltage supply, and response time. When the injector for cylinder 2 fails to operate within factory-specified parameters, the ECM logs this fault. For the ZX360H-5G, this is critical because improper fuel delivery causes power loss, increased emissions, and potential damage to the diesel particulate filter (DPF) and catalytic systems. In used excavators, this fault often stems from wear-related electrical issues rather than injector failure alone.

Common Symptoms

• Engine warning light illuminated on the instrument cluster with possible engine derate mode activation
• Noticeable rough idle or misfiring sensation, particularly at low RPMs
• Loss of power during digging cycles or under heavy hydraulic load
• Increased black or white exhaust smoke due to incomplete combustion in cylinder 2
• Elevated fuel consumption as the ECM attempts to compensate for the malfunctioning cylinder

Potential Causes

The most common causes of Code 14105-2 on used ZX360H-5G excavators include:

• Faulty injector solenoid on cylinder 2 due to internal coil degradation or contamination
• Damaged wiring harness between the ECM and injector, especially where the harness routes near the engine block (known rub point)
• Corroded or loose electrical connectors at the injector plug or ECM interface
• Low voltage supply from a weak battery or failing alternator affecting injector performance
• Failed ECM driver circuit specifically controlling cylinder 2 (less common but possible in high-hour machines)
• Contaminated fuel causing injector sticking or carbon buildup on the solenoid pintle

How to Troubleshoot and Fix Code 14105-2

Step 1: Visual Inspection Begin by inspecting the injector wiring harness for cylinder 2. Check for chafed insulation, broken wires, or oil contamination near the valve cover. Inspect the injector electrical connector for corrosion, bent pins, or moisture intrusion—common issues in used machines operating in wet conditions.

Step 2: Electrical Testing Using a digital multimeter (DMM), measure the injector solenoid resistance at the cylinder 2 connector (disconnected). Typical specification is 0.3-0.7 ohms (consult service manual for exact values). Check supply voltage at the injector connector with ignition on—should read approximately 12 volts. Test the ground circuit continuity back to the ECM.

Step 3: Advanced Diagnostics Connect Hitachi Dr.EX diagnostic software or compatible scan tool to perform an injector cutout test. This isolates each cylinder to confirm if cylinder 2 is the problem. Monitor injector balance rates and compare cylinder 2 to others—variance exceeding ±2 mm³ indicates injector failure.

Step 4: Component Replacement If electrical tests pass but the code persists, the fuel injector itself likely requires replacement. For used excavators, always replace the injector seal and copper washer during installation. Clear codes, perform a fuel system prime, and run the engine through multiple load cycles to verify repair.

Critical Note for Used Equipment: Before replacing expensive injectors, thoroughly inspect all harness routing and connectors. Many 14105-2 codes on high-hour ZX360H-5G machines result from harness wear at vibration points rather than actual injector failure.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual for your specific machine serial number and seek assistance from certified technicians for complex repairs involving fuel system components.