What is Hitachi ZX210LCN-5B Fault Code 14107-2?

Fault Code 14107-2 on the Hitachi ZX210LCN-5B excavator indicates a Fuel Rail Pressure Sensor Circuit Low Voltage condition. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects an abnormally low voltage signal from the fuel rail pressure sensor, typically below the manufacturer's specified threshold of approximately 0.5 volts.

The fuel rail pressure sensor plays a critical role in the common rail fuel injection system by monitoring the high-pressure fuel delivery to the injectors. When this sensor circuit fails or reports incorrect data, the ECM cannot accurately regulate fuel pressure, which directly impacts combustion efficiency, engine performance, and emissions control. For used excavators like the ZX210LCN-5B, this code is particularly concerning as it can lead to power loss and increased fuel consumption.

Common Symptoms

• Engine warning lamp illuminated on the instrument cluster with reduced engine power (derate mode)
• Difficult starting, especially during cold conditions, or extended cranking times
• Rough idling, misfiring, or irregular engine operation under load
• Noticeable loss of hydraulic performance due to reduced engine power output
• Black or white smoke from exhaust indicating improper fuel combustion

Potential Causes

The most frequent causes of Code 14107-2 on used Hitachi ZX210LCN-5B excavators include:

• Damaged sensor wiring harness due to rubbing against engine components or heat shield deterioration (common wear point near the fuel rail)
• Failed or internally shorted fuel rail pressure sensor resulting from prolonged heat exposure or age-related degradation
• Corroded or loose electrical connectors at the sensor or ECM, particularly in machines exposed to moisture or harsh environments
• Broken or chafed wiring in the engine harness, especially at flex points near the engine mounts
• Less commonly, ECM internal circuit failure affecting the sensor reference voltage supply

How to Troubleshoot and Fix Code 14107-2

Step 1: Visual Inspection Begin with a thorough visual examination of the fuel rail pressure sensor and its wiring harness. Check for obvious damage, connector corrosion, pin backing-out, or wire insulation damage. On used excavators, inspect areas where the harness contacts the engine block or passes through metal grommets for chafing.

Step 2: Electrical Testing Using a digital multimeter, verify the sensor's power supply at the connector (should read approximately 5 volts with key on, engine off). Check circuit continuity between the sensor connector and ECM pins. Measure the sensor's output voltage at idle—it should typically range between 0.5-4.5 volts depending on fuel pressure. Any reading below 0.3 volts confirms the low voltage condition.

Step 3: Component Testing and Repair Disconnect the sensor and measure its internal resistance (typically 200-400 ohms for Hitachi sensors). If resistance is infinite or zero, replace the sensor. Before installing new components on used equipment, clean all connector terminals with electrical contact cleaner and apply dielectric grease. If wiring damage is found, repair using OEM-spec heat-resistant wire and proper heat shrink connections rather than simply replacing the sensor.

Step 4: Advanced Diagnostics Use Hitachi Dr.EX diagnostic software or compatible scan tool to monitor live fuel rail pressure data and verify the repair. Clear codes and perform a test cycle under load to confirm proper sensor operation.

Disclaimer: This guide provides general troubleshooting information. Always consult the manufacturer's service manual and consider professional diagnostic assistance for complex electrical issues or if you lack proper diagnostic equipment.