What is Komatsu PC110-7 Fault Code E-15?

Komatsu PC110-7 Fault Code E-15 indicates a malfunction in the hydraulic pump solenoid valve circuit, specifically detecting an electrical abnormality in the pump control system. This code triggers when the engine control module (ECM) identifies abnormal voltage, current draw, or open/short circuit conditions in the proportional solenoid valve that regulates hydraulic pump displacement and flow.

This fault is critical for the PC110-7's performance because the hydraulic pump solenoid directly controls engine load matching and fuel efficiency. When E-15 activates, the machine typically enters a fail-safe mode that limits hydraulic output to protect the engine and hydraulic components, significantly reducing productivity on job sites.

Common Symptoms

When fault code E-15 is active, operators typically experience:

• Reduced hydraulic power across all functions, particularly noticeable during combined operations like digging while slewing
• Intermittent or complete loss of hydraulic response, especially when the machine reaches operating temperature
• Warning light illumination on the monitor panel with possible audible alarm
• Engine may run normally at idle but fails to respond properly under load
• Erratic boom, arm, or bucket movements with inconsistent speed control

Potential Causes

The most common technical causes for E-15 on used PC110-7 excavators include:

• Damaged or corroded wiring harness at common rub points near the hydraulic pump mounting bracket and engine firewall
• Failed proportional solenoid valve coil due to internal short circuit or open winding (resistance typically outside 10-15 ohm specification range)
• Corroded connector pins at the pump solenoid plug, particularly on machines operated in coastal or high-moisture environments
• ECM internal driver circuit failure (less common but documented in units with 8,000+ operating hours)
• Voltage supply issues from the main power harness, including poor ground connections at the pump mounting surface

How to Troubleshoot and Fix Code E-15

Step 1: Initial Visual Inspection Inspect the hydraulic pump solenoid connector for corrosion, bent pins, or moisture infiltration. On used excavators, check the harness routing from the ECM to the pump for wear points against metal brackets—this is a known failure location on PC110-7 models.

Step 2: Electrical Testing Using a digital multimeter, disconnect the solenoid connector and measure coil resistance across the valve terminals. Specification should read 12-14 ohms at 20°C. Also check for voltage supply at the harness side with ignition on (should show battery voltage). Measure resistance to ground on both wires—infinite resistance indicates proper insulation.

Step 3: Harness Continuity Check Trace wiring from the ECM connector (pins typically labeled PMP+ and PMP-) to the solenoid using a wiring diagram. Check for continuity and shorts to ground. On used machines, pay special attention to harness sections passing through rubber grommets where vibration causes conductor breakage.

Step 4: Component Replacement If electrical tests confirm solenoid failure, replace the proportional control valve assembly. Clean all connector contacts with electrical contact cleaner and apply dielectric grease before reconnection. After repair, clear codes using Komatsu KOMTRAX diagnostic software or compatible scan tool and perform operational testing under load.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu service manual for your specific serial number and consider professional diagnostic assistance for complex electrical issues, particularly concerning ECM programming or hydraulic system calibration.