What is Doosan Excavator Fault Code E000168-00?

Fault Code E000168-00 indicates a hydraulic pump solenoid valve circuit malfunction in Doosan excavators. This code is triggered when the Electronic Control Module (ECM) detects an abnormal electrical signal or voltage irregularity in the main pump control solenoid circuit, which regulates hydraulic flow and system pressure.

This fault is critical because the hydraulic pump solenoid valve directly controls the swash plate angle of the main hydraulic pump, determining how much hydraulic power is delivered to all machine functions. When this circuit malfunctions, the excavator's performance, fuel efficiency, and operational safety are immediately compromised. In Doosan machines, this system is particularly sensitive to electrical interference and voltage fluctuations, making proper diagnosis essential for maintaining optimal machine performance.

Common Symptoms

Operators experiencing Code E000168-00 may notice:

• Reduced hydraulic power across all functions (boom, arm, bucket, and swing movements become sluggish)
• Engine derate mode activation, limiting RPM to protect the hydraulic system
• Amber or red warning light illuminated on the instrument cluster with fault code display
• Erratic hydraulic response or inconsistent pressure during combined operations
• Increased fuel consumption due to improper pump compensation and ECM attempting to maintain system pressure

Potential Causes

The most common technical causes for E000168-00 in used Doosan excavators include:

• Damaged or corroded wiring harness connections at the pump solenoid valve (common wear point near the pump mounting area)
• Failed hydraulic pump solenoid valve coil due to internal short circuit or open circuit condition
• Low voltage supply from battery or charging system causing insufficient solenoid activation
• ECM internal fault or corrupted software affecting signal output to the solenoid circuit
• Harness chafing against the pump housing or frame rails (typical in machines with 3,000+ operating hours)
• Moisture infiltration into connectors causing intermittent ground faults or resistance changes

How to Troubleshoot and Fix Code E000168-00

Step 1: Visual Inspection Begin by thoroughly inspecting the wiring harness running from the ECM to the hydraulic pump solenoid valve. On used excavators, check for abraded insulation, corroded connectors, or physical damage near pivot points and the pump mounting bracket. Clean all connector pins with electrical contact cleaner and verify proper seating.

Step 2: Electrical Testing Using a digital multimeter, measure the solenoid coil resistance at the pump valve connector (typically 10-30 ohms for Doosan systems). Check supply voltage at the solenoid connector with the key on—should read battery voltage (12-14V). Verify ground circuit continuity (less than 1 ohm resistance to chassis ground).

Step 3: Signal Testing with Diagnostic Software Connect Doosan DMS (Diagnostic Master System) or compatible diagnostic software to the machine's diagnostic port. Monitor live data for the pump solenoid command signal from the ECM. Command the solenoid on/off using bidirectional controls while observing actual current draw (should be 0.8-1.5 amps when energized).

Step 4: Component Replacement If electrical tests reveal faulty readings, replace the hydraulic pump solenoid valve assembly. For used machines, always replace associated O-rings and seals during solenoid replacement. After installation, clear fault codes, perform hydraulic system calibration using diagnostic software, and conduct a full operational test under load.

Critical for Used Equipment: Before replacing expensive components like the solenoid valve or ECM, carefully inspect for harness wear patterns specific to older Doosan models, particularly where cables contact the rotating platform or pass through bulkheads. Many E000168-00 codes are resolved simply by repairing damaged wiring.

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Disclaimer: This guide provides general troubleshooting information for Doosan excavator fault code E000168-00. Hydraulic and electrical system diagnostics should be performed by qualified heavy equipment technicians with proper training and tools. Always consult the manufacturer's service manual and follow lockout/tagout safety procedures before performing diagnostic or repair work.