What is Yanmar DX75-9C Fault Code E000108-02?

Fault Code E000108-02 on the Yanmar DX75-9C excavator indicates a hydraulic pump solenoid circuit malfunction, specifically a short to ground or open circuit condition in the electronic control system. This code is triggered when the Engine Control Module (ECM) detects an abnormal electrical signal from the hydraulic pump control solenoid, which regulates the variable displacement pump that powers the machine's hydraulic functions.

This fault is critical because the hydraulic pump solenoid directly controls the excavator's hydraulic flow and pressure management. When this circuit malfunctions, the ECM cannot properly modulate hydraulic output based on operator demand, potentially causing reduced performance, erratic hydraulic response, or complete loss of hydraulic function. On the DX75-9C model, this system is integral to fuel efficiency and coordinated work mode operation.

Common Symptoms

• Warning light illuminated on the instrument cluster with fault code displayed on the monitor screen
• Reduced hydraulic power or sluggish response from boom, arm, and bucket functions
• Intermittent loss of hydraulic functions, especially during cold starts or under heavy load
• Engine automatically limiting RPM or entering derate mode to protect the hydraulic system
• Unusual clicking or buzzing sounds from the pump control solenoid area near the main hydraulic pump

Potential Causes

The most common technical causes for Code E000108-02 on used DX75-9C excavators include:

• Damaged wiring harness or chafed wires near the pump mounting area where vibration causes insulation wear
• Failed hydraulic pump solenoid due to internal coil breakdown or contamination from hydraulic fluid ingress
• Corroded or loose electrical connectors at the solenoid or ECM connection points (common in machines with high operating hours)
• Short circuit to ground caused by pinched wiring during previous service work or component replacement
• ECM internal fault or software calibration issues (less common but possible in older units)
• Voltage supply problems from the machine's main electrical system or battery connection issues

How to Troubleshoot and Fix Code E000108-02

Step 1: Visual Inspection Begin by thoroughly inspecting the wiring harness running from the ECM to the hydraulic pump solenoid. On used excavators, check for obvious damage, abraded insulation, or pinch points where the harness contacts the frame or pump housing. Inspect all connector terminals for corrosion, bent pins, or moisture intrusion—clean contacts with electrical contact cleaner if necessary.

Step 2: Electrical Testing Using a digital multimeter, disconnect the solenoid connector and measure resistance across the solenoid coil terminals. Typical specification for Yanmar hydraulic solenoids ranges from 10-30 ohms; consult your service manual for exact values. Next, check for continuity to ground on each wire—any direct ground path indicates a short circuit requiring harness repair or replacement.

Step 3: Voltage Supply Verification With the ignition on (engine off), measure voltage supply at the solenoid connector. You should see battery voltage (approximately 12V) on the power supply wire. If voltage is absent, trace back toward the ECM checking for blown fuses, damaged relays, or ECM output issues.

Step 4: Solenoid Functional Test If electrical values are within specification, the solenoid itself may have failed internally. Replace the hydraulic pump control solenoid and clear the fault code using Yanmar diagnostic software or a compatible scan tool. For used machines, always inspect the solenoid mounting area for hydraulic fluid leaks that may have contaminated the electrical components.

Step 5: Post-Repair Verification After repairs, clear all fault codes, operate the excavator through full hydraulic cycles, and monitor for code recurrence. Check that all work modes (power, standard, economy) function correctly and hydraulic response has returned to normal.

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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. If you're unfamiliar with electrical diagnostics or hydraulic systems, consult a certified Yanmar technician to prevent equipment damage or personal injury.