Doosan Excavator Fault Code E000173-00: Complete Diagnostic Guide

What is Doosan Fault Code E000173-00?

Fault Code E000173-00 indicates a Main Relief Valve Solenoid Circuit malfunction in Doosan excavators. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects an abnormal voltage or current reading in the main relief valve solenoid circuit, typically indicating an open circuit, short circuit, or solenoid resistance outside manufacturer specifications.

The main relief valve solenoid controls hydraulic system pressure, protecting the pump and hydraulic components from overpressure conditions. When this circuit fails, the excavator's hydraulic system cannot properly regulate maximum pressure, potentially causing catastrophic pump damage or unsafe operating conditions. This is especially critical in Doosan machines, where precise hydraulic pressure control directly affects digging force, swing speed, and attachment performance.

Common Symptoms

When fault code E000173-00 is active, operators typically experience:

• Illuminated warning light on the instrument cluster, often accompanied by a hydraulic system alert icon
• Reduced hydraulic performance with decreased digging force and slower cycle times
• Erratic hydraulic pressure causing inconsistent boom, arm, or bucket movements
• Engine derate mode where maximum RPM is limited to protect hydraulic components
• Audible alarm sounding intermittently during operation, particularly under heavy load conditions

Potential Causes

The most common technical causes for E000173-00 in used Doosan excavators include:

• Failed main relief valve solenoid due to coil burnout or internal mechanical failure (common after 5,000+ operating hours)
• Damaged wiring harness at known rub points near the main control valve assembly, especially where harnesses contact the frame
• Corroded or loose electrical connectors at the solenoid or ECM connections, frequently caused by hydraulic oil contamination
• ECM internal fault or software corruption requiring reprogramming
• Voltage supply issues from the machine's electrical system affecting solenoid energization
• Hydraulic oil contamination causing solenoid valve sticking and increased current draw

How to Troubleshoot and Fix Code E000173-00

Step 1: Visual Inspection Begin by inspecting the main relief valve solenoid located on the main control valve assembly. Check for physical damage, oil leaks, or burnt connectors. On used excavators, carefully examine the wiring harness routing for abrasion points where cables contact metal surfaces, particularly near the turntable area.

Step 2: Electrical Testing Using a digital multimeter, disconnect the solenoid connector and measure resistance across the solenoid terminals. Typical specifications range from 12-25 ohms (verify with Doosan service manual). Next, check for supply voltage at the harness connector with ignition on—should read approximately 12-24V DC depending on machine configuration.

Step 3: Connector and Harness Verification Inspect all connectors for corrosion, bent pins, or hydraulic oil intrusion. Clean contacts with electrical contact cleaner. Check harness continuity from the solenoid to the ECM connector using a multimeter, ensuring less than 1 ohm resistance and no shorts to ground.

Step 4: Solenoid Replacement or Repair If resistance or voltage readings are out of specification, replace the main relief valve solenoid. For used machines, always replace associated O-rings and seals to prevent future oil contamination. After replacement, clear codes using Doosan diagnostic software (DMS) or compatible scan tool.

Step 5: System Verification Start the machine and monitor hydraulic pressure using onboard diagnostics. Perform functional tests of all hydraulic circuits under varying loads to ensure proper pressure regulation and code elimination.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Doosan service manual for your specific model and serial number. If you lack proper diagnostic tools or experience with high-pressure hydraulic systems, consult a certified Doosan technician to prevent injury or equipment damage.