What is Hitachi ZX210LCH-5G Fault Code 14105-2?

Fault Code 14105-2 indicates a hydraulic pump displacement sensor circuit malfunction, specifically a voltage signal abnormality (high or low) detected by the Engine Control Module (ECM). This code triggers when the displacement sensor on the variable displacement hydraulic pump fails to send proper voltage signals to the controller, preventing accurate pump flow regulation.

On the Hitachi ZX210LCH-5G, this sensor is critical for the pump flow control system that matches hydraulic output to operational demand. The ECM continuously monitors sensor voltage (typically 0.5-4.5V range) to adjust pump swash plate angle. When voltage falls outside parameters, the system defaults to limp mode to prevent pump damage, severely limiting machine productivity and potentially causing costly downtime on used equipment where sensor degradation is common.

Common Symptoms

• Hydraulic power loss or noticeably reduced boom/arm/bucket speed during operation
• Engine overspeed or irregular RPM fluctuations under load due to improper pump displacement
• Warning lamp illumination on the instrument cluster (typically hydraulic system alert)
• Erratic hydraulic response when operating multiple functions simultaneously
• Increased fuel consumption as the ECM cannot optimize pump output efficiently

Potential Causes

The most frequent causes on used ZX210LCH-5G excavators include:

• Displacement sensor internal failure – common after 5,000+ operating hours due to heat cycling and vibration
• Damaged wiring harness at known rub points near the pump mounting bracket where cables contact the frame
• Corroded or loose connector pins at the 6-pin sensor connector, especially on machines operated in wet/salty environments
• ECM voltage supply issues – faulty 5V reference voltage from the controller
• Contaminated hydraulic oil causing sensor mechanical binding or electrical interference
• Previous repair attempts with incorrect sensor specifications or aftermarket parts

How to Troubleshoot and Fix Code 14105-2

Step 1: Visual Inspection Inspect the displacement sensor located on the main hydraulic pump body (left side of engine). Check the wiring harness from sensor to ECM for abrasion, cuts, or melting. On used excavators, pay special attention to the harness routing near the pump—this model has a known wear point where cables rub against the mounting bracket during engine vibration.

Step 2: Electrical Testing Using a digital multimeter, backprobe the sensor connector (engine running, pump at idle). Verify reference voltage from ECM is 4.8-5.2V on the supply wire. Check signal wire voltage varies smoothly between 0.5-4.5V when manually moving pump displacement control (requires accessing pump adjustment—consult service manual). Resistance between sensor ground and chassis should be less than 1 ohm.

Step 3: Connector and Component Inspection Disconnect the sensor 6-pin connector and inspect for green corrosion, bent pins, or moisture. Clean with electrical contact cleaner and apply dielectric grease. If voltage readings were erratic, replace the sensor (OEM Hitachi part recommended for longevity). If voltage supply from ECM is absent, check ECM fuses and wiring continuity.

Step 4: System Verification After repairs, clear codes using Hitachi Dr.EX diagnostic software or compatible scan tool. Perform hydraulic function test under load. Monitor live data to confirm sensor voltage responds correctly (0.8V at minimum displacement, 4.2V at maximum). For used machines, change hydraulic oil and filter if contamination was found, as particles can re-contaminate the new sensor.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual for your specific machine serial number. If unfamiliar with hydraulic systems or electrical diagnostics, seek assistance from a certified heavy equipment technician to avoid injury or further damage.