What is Doosan Excavator Fault Code E000157-18?

Fault Code E000157-18 indicates a Hydraulic Pump Solenoid Valve Circuit Failure with an open circuit or short to ground condition. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects abnormal electrical resistance or voltage readings in the proportional solenoid valve circuit that controls main hydraulic pump displacement.

This code is critical for Doosan excavators because the hydraulic pump solenoid valve directly regulates hydraulic flow and pressure based on operator demand. When this circuit malfunctions, the ECM cannot properly modulate pump output, leading to reduced machine performance, inefficient fuel consumption, and potential hydraulic system damage. On used excavators, this fault often stems from age-related electrical degradation rather than mechanical pump failure.

Common Symptoms

Operators may experience the following when Code E000157-18 is active:

• Reduced hydraulic power across all functions (boom, arm, bucket, swing) with sluggish response times
• Engine warning light or malfunction indicator illuminated on the instrument panel
• Erratic hydraulic performance with inconsistent flow rates during simultaneous multi-function operations
• Engine derate mode activation, limiting RPM to protect the hydraulic system from damage
• Abnormal engine sound as the ECM attempts to compensate for improper pump displacement control

Potential Causes

The most common technical causes for this fault code include:

• Damaged wiring harness between the ECM and hydraulic pump solenoid, particularly at known rub points near the pump mounting area or swing bearing passage
• Corroded or moisture-contaminated connectors at the solenoid valve plug or ECM interface (extremely common on used machines)
• Failed proportional solenoid valve within the hydraulic pump assembly due to coil burnout or internal short
• ECM internal driver circuit failure causing inability to supply proper voltage to the solenoid
• Broken or chafed wires inside protective loom due to machine vibration and age-related insulation breakdown

How to Troubleshoot and Fix Code E000157-18

Step 1: Visual Inspection Begin with a thorough inspection of the wiring harness from the ECM to the hydraulic pump solenoid valve. On used excavators, focus on areas where harnesses contact frame members, hydraulic lines, or pass through bulkheads. Look for abraded insulation, crushed wires, or oil contamination that degrades wire integrity.

Step 2: Connector and Pin Testing Disconnect the solenoid valve connector at the hydraulic pump. Inspect for corrosion, bent pins, or moisture intrusion. Using a digital multimeter, measure resistance across the solenoid terminals—typical specification is 3-8 ohms (consult Doosan service manual for exact values). Infinite resistance indicates an open coil; near-zero resistance suggests a short circuit.

Step 3: Circuit Voltage and Continuity Checks With the connector still disconnected and ignition on, measure supply voltage at the harness side—should read battery voltage (approximately 12-14V). Check ground continuity between the solenoid ground wire and chassis ground (should be less than 1 ohm). Test for short to ground by measuring resistance between each circuit wire and chassis with all connections separated.

Step 4: Solenoid Replacement or Harness Repair If the solenoid coil tests faulty, replace the proportional solenoid valve assembly on the hydraulic pump. If wiring shows damage, repair or replace the affected harness section, ensuring proper routing away from heat sources and moving components. For used excavators, consider applying dielectric grease to all connectors during reassembly to prevent future corrosion.

Step 5: Clear Code and Verify Repair Use Doosan diagnostic software (DMS or G-Scan) to clear the fault code from ECM memory. Operate the machine through all hydraulic functions under load and monitor for code recurrence. Verify proper hydraulic response and engine performance return to normal specifications.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Doosan service manual for your specific model and serial number. If you lack proper diagnostic tools or electrical testing experience, consult a certified Doosan service technician to prevent further damage to expensive components.