Doosan DX150LC-9C Fault Code E520713-12: Complete Diagnostic Guide

What is Doosan DX150LC-9C Fault Code E520713-12?

Fault Code E520713-12 indicates a hydraulic pump solenoid valve control circuit malfunction in the Doosan DX150LC-9C excavator's main control system. This code specifically signals that the Electronic Control Unit (ECU) has detected an abnormal electrical signal or open/short circuit condition in the variable displacement pump's solenoid valve wiring harness.

This fault directly affects the excavator's hydraulic pump flow control system, which regulates engine load matching and hydraulic power distribution. The DX150LC-9C uses an advanced electronic proportional control system that continuously adjusts pump output based on operator demand. When this circuit fails, the machine cannot optimize fuel efficiency or maintain proper hydraulic response, potentially causing significant performance degradation and increased operating costs.

Common Symptoms

When fault code E520713-12 is active, operators typically experience:

• Warning light illumination on the instrument cluster with possible alarm buzzer activation
• Reduced hydraulic power across all functions (boom, arm, bucket, and swing movements become sluggish)
• Engine RPM fluctuations or inability to maintain consistent working speed under load
• Automatic engine derate mode where maximum RPM is limited to protect the drivetrain
• Erratic hydraulic response with delayed reaction to joystick inputs or inconsistent cycle times

Potential Causes

The most common technical failures triggering E520713-12 in used DX150LC-9C excavators include:

• Damaged wiring harness between the ECU and pump solenoid valve, particularly at flex points near the pump mounting location where cable movement causes insulation wear
• Failed solenoid valve coil within the hydraulic pump assembly due to internal short circuit or open winding (resistance typically should measure 8-15 ohms)
• Corroded or loose electrical connectors at the pump solenoid or ECU terminals, especially in machines operating in wet/marine environments
• ECU internal fault in the solenoid driver circuit, though less common than field wiring issues
• Voltage supply problems from the main power distribution harness or poor grounding connections

How to Troubleshoot and Fix Code E520713-12

Step 1: Visual Inspection and Connector Check Begin by inspecting the pump solenoid connector located on the main hydraulic pump (right side of engine). Disconnect the connector and examine pins for corrosion, bent terminals, or moisture intrusion. Clean with electrical contact cleaner and check for proper pin seating. On used excavators, this connector frequently experiences vibration-related wear.

Step 2: Resistance and Voltage Testing Using a digital multimeter, measure solenoid coil resistance at the pump-side connector (disconnected). Typical specification is 10-12 ohms at 20°C. Next, check supply voltage at the harness-side connector with ignition ON—should read approximately 12V DC. If voltage is absent, trace the harness back toward the ECU checking for breaks or chafing damage.

Step 3: Harness Continuity and Ground Verification Test continuity between the ECU connector (typically pin locations specified in service manual as terminals 47 and 48) and the pump solenoid connector. Resistance should be less than 1 ohm. Check ground circuit integrity to chassis—poor grounds are common in older machines. Inspect harness routing near the turntable bearing where cable flexing occurs during swing operation.

Step 4: Component Replacement and Code Clearing If solenoid resistance is out of specification or harness damage is confirmed, replace the failed component. For used excavators, consider replacing both the solenoid and associated harness section if wiring shows age-related deterioration. After repairs, clear codes using Doosan DMS diagnostic software or compatible scan tool and perform function tests under load.

---

Disclaimer: This guide provides general diagnostic information. Always consult the official Doosan service manual for your specific serial number and seek professional assistance from certified technicians for complex electrical repairs or if safety concerns exist.