Doosan DX150LC-9C Fault Code E000105-04: Complete Diagnostic Guide

What is Doosan DX150LC-9C Fault Code E000105-04?

Fault Code E000105-04 indicates a Swing Motor Control Valve (SMCV) solenoid circuit malfunction with a current below normal range on the Doosan DX150LC-9C excavator. This code specifically signals that the Electronic Control Module (ECM) has detected insufficient electrical current flowing through the swing motor proportional control valve solenoid circuit, typically below the manufacturer's specified threshold of 200-800mA during operation.

This fault directly affects the swing drive system's proportional control capability. The swing motor control valve regulates hydraulic flow to the swing motor, allowing smooth, variable-speed rotation of the upper structure. When the solenoid circuit fails to maintain proper current, the ECM cannot accurately modulate swing speed, potentially defaulting to mechanical pilot control or limiting swing function entirely. For the DX150LC-9C's electronically-controlled hydraulic system, this represents a critical loss of precision control that impacts productivity and operator safety.

Common Symptoms

• Swing function completely inoperative or only works intermittently with jerky, uncontrolled movements
• Dashboard warning light illuminated with fault code E000105-04 displayed on the monitor panel
• Swing speed cannot be modulated smoothly; machine may only swing at maximum or minimum speed
• ECM derate mode activated, potentially limiting engine RPM or other hydraulic functions as a protective measure
• Audible clicking or buzzing from the main control valve area when attempting swing operations

Potential Causes

The most common technical failures causing this specific code on used DX150LC-9C excavators include:

• Open circuit in solenoid wiring harness due to wire breakage, particularly at flex points near the swing bearing where cables experience constant rotation and flexing
• Corroded or loose connector pins at the swing motor control valve solenoid connector (typically located on the main control valve assembly)
• Failed swing motor control valve solenoid coil with internal winding damage causing high resistance or complete open circuit
• Damaged wiring harness from rubbing against the uppercarriage frame or hydraulic lines, common on machines with 3,000+ operating hours
• ECM internal driver circuit failure (less common) preventing proper current supply to the solenoid
• Blown fuse or faulty relay in the swing control circuit power supply path
• Water intrusion into connectors from damaged cab floor seals or hydraulic line leaks contaminating electrical connections

How to Troubleshoot and Fix Code E000105-04

Step 1: Initial Visual Inspection Begin by accessing the main control valve located beneath the operator's cab. Inspect the swing motor control valve solenoid connector for obvious damage, corrosion, or loose connections. On used excavators, pay special attention to harness routing through the swing bearing area—look for abraded insulation, pinched wires, or areas where the harness contacts metal edges. Check for hydraulic oil contamination on electrical connectors, which is common on older machines.

Step 2: Electrical Testing with Multimeter Disconnect the solenoid connector and measure solenoid coil resistance using a digital multimeter. The swing motor control valve solenoid should typically read between 3-8 ohms (consult service manual for exact specifications). A reading of infinite resistance indicates an open coil requiring solenoid replacement. Next, check for supply voltage at the harness connector with ignition on—you should see battery voltage (12-14V) on the power supply pin. If voltage is absent, trace the power supply circuit back toward the ECM, checking fuses and relays.

Step 3: Harness Continuity and Ground Testing With connectors still disconnected, test harness continuity from the control valve connector back to the ECM connector. There should be less than 1 ohm resistance on each wire. Focus testing on the harness section that passes through the swing bearing rotary coupling, as this is the highest-wear area on used machines. Inspect the ground circuit carefully—corrosion on ground points is a frequent cause of low-current faults. Clean all ground connections with electrical contact cleaner and ensure tight, corrosion-free mounting.

Step 4: Advanced Diagnostics If basic checks pass, connect Doosan DMS diagnostic software (Doosan Machine System) to monitor real-time solenoid current draw during operation. The system should show current values between 200-800mA depending on swing command input. Values consistently below 200mA with the solenoid and harness testing good indicate potential ECM driver circuit failure. Before replacing the ECM, verify all connector pin tensions are correct—worn female pins can create intermittent high-resistance connections that mimic solenoid failures.

Critical Note for Used Excavators: On machines with over 5,000 hours, always inspect the swing bearing cable carrier for mechanical wear. Repeated rotation can fatigue wiring even without visible damage. Consider replacing the entire harness section through the swing bearing if the machine history shows previous electrical issues, as this prevents recurring failures.

---

Disclaimer: This guide provides general diagnostic information for experienced technicians. Always consult the official Doosan service manual for your specific serial number range and follow proper safety procedures. If you lack specialized diagnostic tools or experience with high-voltage electrical systems, consult a certified Doosan service technician to prevent equipment damage or personal injury.