What is Hitachi ZX210LC-5G Fault Code 14105-2?

Fault Code 14105-2 indicates a malfunction in the hydraulic pump discharge pressure sensor circuit, specifically detecting an abnormal voltage signal or intermittent connection within the pressure monitoring system. This code is triggered when the Engine Control Module (ECM) receives voltage readings outside the acceptable range (typically 0.5-4.5V) from the discharge pressure sensor that monitors main hydraulic pump output.

This diagnostic trouble code is critical for the ZX210LC-5G because the hydraulic pump discharge pressure directly affects all machine functions—from boom/arm movement to swing operation. The ECM uses this pressure data to optimize engine load, prevent hydraulic overload, and regulate fuel injection timing. When this sensor circuit fails, the machine loses critical feedback necessary for efficient hydraulic-engine coordination, potentially causing performance degradation or component damage.

Common Symptoms

• Hydraulic system derate: Noticeably reduced boom speed, sluggish arm movements, or weak bucket breakout force
• Engine power limitation: ECM may restrict engine RPM to protect the system from unmonitored pressure spikes
• Warning light activation: Monitor panel displays hydraulic system warning indicator or check engine light
• Erratic hydraulic response: Inconsistent implement speed or pressure during combined operations (e.g., boom lift while swinging)
• Fuel consumption anomalies: Increased diesel usage due to improper engine-pump load matching

Potential Causes

In used ZX210LC-5G excavators, this fault typically stems from age-related deterioration:

• Sensor connector corrosion: The discharge pressure sensor connector (located near the main pump) accumulates moisture, causing voltage fluctuations or open circuits
• Wiring harness damage: Harness chafing at known rub points between the pump and frame rail, particularly where routing passes near swing bearing
• Sensor internal failure: Pressure transducer diaphragm fatigue or internal circuit degradation after 5,000+ operating hours
• ECM ground circuit issues: Corroded ground terminals (G103 or G104) affecting sensor reference voltage
• Hydraulic contamination: Metal particles from worn pump components damaging sensor element

How to Troubleshoot and Fix Code 14105-2

Step 1: Visual Inspection and Connector Check Begin by locating the hydraulic pump discharge pressure sensor on the main pump assembly. Disconnect the sensor connector and inspect for corrosion, bent pins, or moisture intrusion. On used machines, clean connectors with electrical contact cleaner and apply dielectric grease to prevent future corrosion.

Step 2: Voltage and Resistance Testing Using a digital multimeter (DMM), measure sensor supply voltage at the harness connector with ignition ON—should read approximately 5.0V ± 0.25V. Check sensor ground circuit for continuity to ECM ground (resistance should be less than 1 ohm). Test the sensor itself by measuring resistance across terminals (typical specification: 200-500 ohms, consult service manual).

Step 3: Harness Continuity and Rub Point Inspection Trace the sensor wiring harness from pump to ECM, paying special attention to areas near the swing post and hydraulic tank where harness movement causes wear. Check for insulation breakdown or exposed copper. For used excavators with 4,000+ hours, inspect harness securing clips—loose routing accelerates wire fatigue.

Step 4: Sensor Replacement and System Verification If sensor and wiring test within specifications but code persists, replace the discharge pressure sensor (Hitachi Part #4621072). After installation, clear fault codes using Hitachi diagnostic software (Dr.EX) or compatible scan tool. Cycle hydraulic functions through full range while monitoring live pressure data to confirm proper sensor operation (typical range: 0-400 bar/0-5,800 PSI).

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi ZX210LC-5G service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs may void warranties or cause equipment damage.