What is Doosan Excavator Fault Code E002791-08?

Fault Code E002791-08 indicates a hydraulic pump solenoid circuit malfunction, specifically detecting an open circuit or abnormal voltage in the main pump control solenoid system. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects that the electrical signal to the hydraulic pump's proportional solenoid valve is outside the manufacturer's specified parameters, typically between 0.5-4.5 volts.

This code directly affects the excavator's hydraulic system performance because the pump solenoid regulates hydraulic flow and pressure based on operator input and load demands. When this circuit fails, the ECM cannot properly modulate pump output, leading to reduced machine efficiency and potential protection mode activation. For Doosan excavators—especially used models with extended operating hours—this code often signals degraded wiring harnesses or solenoid coil deterioration rather than complete component failure.

Common Symptoms

• Hydraulic system derate or reduction in swing, boom, and bucket speed despite full joystick input
• Intermittent or constant warning light on the instrument cluster, sometimes accompanied by audible alarms
• Erratic pump response, with the machine feeling sluggish during combined hydraulic functions
• Engine RPM fluctuations when attempting heavy digging or lifting operations
• Complete loss of hydraulic power in severe cases, forcing the machine into limp mode

Potential Causes

The most common technical causes for E002791-08 in used Doosan excavators include:

• Damaged wiring harness near the main pump assembly, particularly where the harness routes along the swing bearing or near rotating components (known wear point on models with 4,000+ hours)
• Failed pump solenoid coil due to heat exposure, moisture intrusion, or internal short circuit
• Corroded or loose electrical connectors at the pump solenoid or ECM connection points
• ECM internal driver circuit failure, though less common than external wiring issues
• Voltage supply problems from the machine's main power harness, including poor grounds or battery connection issues

How to Troubleshoot and Fix Code E002791-08

Step 1: Initial Visual Inspection Begin by disconnecting the battery and inspecting the pump solenoid connector for corrosion, bent pins, or moisture. On used excavators, check the wiring harness routing from the ECM to the pump—look specifically for harness rub points against frame members or hydraulic lines. Pay attention to areas where zip ties have failed and allowed harness movement.

Step 2: Electrical Testing Using a digital multimeter, measure the solenoid coil resistance at the pump-side connector (disconnected). Typical specifications range from 8-15 ohms; consult your service manual for exact values. Next, check for supply voltage at the harness side with the key on—you should see battery voltage (12-14V) on the power supply pin.

Step 3: Circuit Continuity and Signal Testing With the harness connected and key on, backprobe the solenoid connector to measure the PWM control signal voltage during operation (requires Doosan diagnostic software or oscilloscope). The signal should modulate between 0.5-4.5 volts based on hydraulic demand. If voltage is absent or reads battery voltage constantly, suspect ECM driver circuit failure or a short to power in the harness.

Step 4: Component Replacement and Verification For used machines, if wiring passes all tests, replace the pump proportional solenoid assembly. After replacement, clear codes using diagnostic software and perform a full hydraulic system function test under load. Monitor for code recurrence over several operating cycles.

Disclaimer: This guide provides general troubleshooting information. Always consult the manufacturer's service manual and consider professional diagnostic services for complex electrical issues or if you lack proper testing equipment.