What is Hitachi ZX870LC-5A Fault Code 20113-2?

Fault Code 20113-2 on the Hitachi ZX870LC-5A (HCMC) indicates a hydraulic pump control system malfunction, specifically related to the main pump displacement sensor circuit experiencing an abnormal voltage signal or intermittent connection. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects voltage readings outside the acceptable range (typically 0.5-4.5V) from the pump displacement feedback sensor.

This code is critical for the ZX870LC-5A because the main hydraulic pump displacement control directly affects engine load management, fuel efficiency, and overall machine performance. When the ECM cannot accurately read pump displacement, it may default to a protective mode that limits hydraulic flow, reducing operational capacity and potentially causing the machine to enter derate mode.

Common Symptoms

• Reduced hydraulic power across all functions, with noticeably slower boom, arm, and bucket movements
• Intermittent engine RPM fluctuations during heavy load operations due to improper pump control
• Warning light activation on the instrument cluster, often accompanied by audible alarm
• Erratic fuel consumption patterns as the ECM struggles to match engine output with hydraulic demand
• Machine entering limp mode where hydraulic functions are severely limited to prevent damage

Potential Causes

The most common causes of Code 20113-2 on used ZX870LC-5A excavators include:

• Worn or damaged displacement sensor on the main hydraulic pump (Kawasaki K5V series pump common on this model)
• Corroded or loose electrical connectors at the pump sensor harness connection point
• Wiring harness chafing where the sensor cable routes near the hydraulic pump mounting bracket—a known wear point on high-hour machines
• Contaminated hydraulic oil causing sensor mechanical binding or internal pump control valve sticking
• ECM voltage supply issues providing inconsistent reference voltage to the sensor circuit
• Water intrusion into sensor connector due to damaged seals or improper maintenance

How to Troubleshoot and Fix Code 20113-2

Step 1: Visual Inspection and Connector Check Begin by thoroughly inspecting the main pump displacement sensor and its wiring harness. On used excavators, focus on areas where the harness may contact the pump housing or frame. Disconnect the sensor connector and examine for corrosion, bent pins, or moisture. Clean with electrical contact cleaner and check the rubber seal integrity.

Step 2: Electrical Testing with Multimeter Using a digital multimeter (DMM), perform a resistance check on the sensor itself (typically 1-3kΩ at room temperature for most Hitachi displacement sensors). Next, check for supply voltage at the harness connector with the ignition on—you should see approximately 5V reference voltage. Measure signal wire voltage while manually moving the pump displacement control if accessible; voltage should change smoothly between 0.5-4.5V.

Step 3: Sensor Signal Monitoring Connect Hitachi diagnostic software (Dr.EX or compatible tool) to monitor live sensor data. Observe the displacement sensor voltage while operating the machine through various hydraulic functions. Erratic readings, dropouts, or values stuck at extremes indicate sensor failure or wiring issues.

Step 4: Component Replacement and Verification If testing confirms sensor failure, replace the pump displacement sensor with a genuine Hitachi or OEM-equivalent part. For used machines with high hours (8,000+), inspect the sensor mounting bore for wear and ensure proper O-ring sealing. After replacement, clear codes using diagnostic software, cycle the ignition, and perform a function test. Verify the code does not return and hydraulic performance is restored.

Crucial for Used Equipment: Always check harness routing and support clips that may have degraded over time, causing wire movement and intermittent connections. Examine hydraulic oil condition—contaminated fluid may indicate pump internal wear requiring more extensive repairs beyond sensor replacement.

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Disclaimer: This guide provides general troubleshooting information for Code 20113-2. Always consult the official Hitachi service manual for your specific machine serial number and seek professional assistance from certified Hitachi technicians for complex hydraulic system diagnostics and repairs.