Doosan DX220LC-9C Fault Code E000174-01: Complete Diagnostic Guide

What is Doosan DX220LC-9C Fault Code E000174-01?

Fault Code E000174-01 indicates a hydraulic oil temperature sensor circuit malfunction in the Doosan DX220LC-9C excavator. This code triggers when the Electronic Control Module (ECM) detects an abnormal voltage reading from the hydraulic oil temperature sensor, which monitors the operating temperature of the hydraulic system.

This sensor plays a critical role in the DX220LC-9C's performance management system. The ECM uses temperature data to adjust hydraulic pump output, activate cooling fans, and prevent thermal damage to hydraulic components. When this circuit fails, the machine cannot properly regulate hydraulic system temperatures, potentially leading to accelerated component wear or catastrophic hydraulic failure.

Common Symptoms

Operators experiencing fault code E000174-01 typically notice:

• Warning light illumination on the instrument cluster with reduced machine performance
• Hydraulic fan running continuously at maximum speed, regardless of actual oil temperature
• Derated hydraulic power with slower cycle times and reduced lifting capacity
• Error message displayed on the LCD monitor indicating hydraulic system fault
• Intermittent code activation during cold starts or after extended operation periods

Potential Causes

The most common technical causes for E000174-01 in used DX220LC-9C excavators include:

• Failed hydraulic oil temperature sensor due to thermal cycling and age-related deterioration
• Damaged or corroded wiring harness near the hydraulic tank mounting area where vibration causes wire chafing
• Loose or oxidized connector pins at the sensor connection point, especially on machines operating in humid environments
• ECM internal circuit failure affecting the sensor input channel (rare but documented in high-hour machines)
• Contaminated sensor threads causing poor ground connection to the hydraulic tank

How to Troubleshoot and Fix Code E000174-01

Step 1: Visual Inspection Locate the hydraulic oil temperature sensor mounted on the hydraulic tank (typically on the return side). Inspect the wiring harness for visible damage, especially where it routes near moving components or sharp edges. Check the connector for corrosion, bent pins, or oil contamination—common issues in used excavators.

Step 2: Electrical Testing Disconnect the sensor and measure resistance across the sensor terminals using a digital multimeter. At 68°F (20°C), resistance should read approximately 2,000-3,000 ohms (consult your service manual for exact specifications). Test harness continuity from the sensor connector back to the ECM. Check for short circuits to ground.

Step 3: Voltage Supply Check With the ignition on and sensor disconnected, measure voltage supply at the harness connector. You should see approximately 5 volts reference voltage from the ECM. If voltage is absent or incorrect, suspect ECM issues or harness damage.

Step 4: Advanced Diagnostics Use Doosan DMS (Diagnostic Monitoring System) software with a compatible interface to monitor real-time sensor values. Compare readings against actual hydraulic oil temperature using an infrared thermometer. For used excavators, thoroughly clean sensor mounting threads and apply anti-seize compound during reinstallation to ensure proper grounding.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Doosan service manual and consider professional diagnostic assistance for complex electrical issues or if you're unfamiliar with high-voltage systems.