What is Yanmar DX75-9C Fault Code E000110-04?

Fault Code E000110-04 on the Yanmar DX75-9C excavator indicates a "Hydraulic Pump Solenoid Circuit - Current Below Normal" condition. This code is triggered when the Engine Control Module (ECM) detects abnormally low electrical current flowing through the hydraulic pump control solenoid circuit, typically below the manufacturer's specified threshold of approximately 200-300 milliamps during normal operation.

This fault specifically affects the electronic control system that regulates hydraulic pump output on the DX75-9C's load-sensing hydraulic system. The proportional solenoid valve controls pump displacement based on operational demands, and when current drops below normal parameters, the ECM cannot properly modulate hydraulic flow. This is critical because improper pump control directly impacts digging force, swing speed, and overall machine productivity while potentially causing the excavator to enter a derated performance mode to protect system components.

Common Symptoms

• Reduced hydraulic power across all functions, with noticeably sluggish boom, arm, and bucket movements
• Amber warning light illuminated on the instrument cluster with fault code displayed on the monitor
• Inconsistent hydraulic response where the machine operates normally during warm-up but loses power under load
• Engine runs normally but hydraulic functions feel weak or unresponsive, particularly during combined operations
• Intermittent fault code that may clear and return, especially when operating in wet or dusty conditions

Potential Causes

The most common technical causes for Code E000110-04 on used DX75-9C excavators include:

• Damaged or corroded wiring harness in the engine compartment, particularly where the harness routes near the hydraulic pump mounting area (known rub point on this model)
• Failed hydraulic pump proportional solenoid, often due to internal coil breakdown or contamination from hydraulic fluid ingress
• Corroded or loose connector pins at the solenoid connection point, especially on machines with high operating hours in wet environments
• Open circuit in the solenoid wiring, frequently caused by harness chafing against frame members during long-term operation
• ECM internal driver circuit failure, less common but possible on high-hour machines (typically above 6,000 hours)
• Poor ground connection at the ECM or pump mounting bracket causing voltage drop

How to Troubleshoot and Fix Code E000110-04

Step 1: Visual Inspection and Connector Check Begin by performing a thorough visual inspection of the hydraulic pump solenoid wiring harness from the ECM to the pump. On used excavators, pay special attention to areas where the harness passes near sharp edges or moving components. Disconnect the solenoid connector and inspect for corrosion, bent pins, or moisture intrusion. Clean connections with electrical contact cleaner and apply dielectric grease before reconnecting.

Step 2: Solenoid Resistance Testing Using a digital multimeter (DMM), measure the resistance across the solenoid terminals with the connector disconnected. The hydraulic pump solenoid should typically read between 8-15 ohms at room temperature (consult your service manual for exact specifications). A reading of infinite resistance indicates an open coil, while very low resistance (below 5 ohms) suggests a short circuit. Replace the solenoid if readings fall outside specifications.

Step 3: Circuit Continuity and Voltage Testing With the ignition on and engine off, backprobe the solenoid connector to verify the ECM is supplying proper voltage (typically 12V reference voltage). Check continuity from the ECM connector to the solenoid harness using a wiring diagram to identify proper pin locations. For used machines, probe the harness at multiple points to locate potential internal wire breaks caused by vibration fatigue.

Step 4: Current Flow Testing If voltage and resistance check out, use a current clamp meter or install the solenoid with an inline ammeter to measure actual current draw during operation. The circuit should draw between 250-400 milliamps under normal modulation. Low current despite proper voltage indicates solenoid internal resistance problems or poor ground connections.

Step 5: Ground Circuit Verification Check the ground circuit integrity by measuring voltage drop between the solenoid ground and battery negative while the system is energized. Voltage drop should not exceed 0.2 volts. On used excavators, corrosion at ground points is extremely common—remove, clean, and secure all ground connections at the pump mounting area and ECM chassis ground.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Yanmar service manual for your specific machine serial number and use proper diagnostic tools. If you're uncomfortable performing electrical diagnostics, consult a certified Yanmar technician to prevent further damage to expensive electronic components.