What is Komatsu PC210LC-7 Fault Code E115?

Fault Code E115 on the Komatsu PC210LC-7 indicates a malfunction in the pump control solenoid valve circuit, specifically related to the main hydraulic pump's electronic control system. This code is triggered when the Engine Control Module (ECM) detects an abnormal voltage or open/short circuit condition in the solenoid that regulates hydraulic pump output based on load demand.

This fault is critical because the pump control solenoid directly affects the excavator's ability to match hydraulic flow to operational requirements. The PC210LC-7 uses an advanced load-sensing hydraulic system where the ECM continuously adjusts pump displacement through this solenoid valve. When E115 appears, the machine typically enters a failsafe mode that limits hydraulic performance, directly impacting cycle times, digging force, and fuel efficiency.

Common Symptoms

When Code E115 is active on your PC210LC-7, operators typically experience:

• Reduced hydraulic power across all functions (boom, arm, bucket, and swing movements become noticeably slower)
• Illuminated warning lamp on the monitor panel, often accompanied by an audible alarm
• Erratic hydraulic response where the machine alternates between normal and reduced power output
• Increased engine RPM without corresponding hydraulic performance (engine compensating for restricted flow)
• Monitor display showing the E115 error code when accessed through the diagnostic menu

Potential Causes

The most common technical causes for E115 on used PC210LC-7 excavators include:

• Solenoid valve coil failure due to age-related insulation breakdown or overheating (resistance typically measures outside the 10-30 ohm specification range)
• Wiring harness damage at known rub points near the hydraulic pump mounting area, especially where the harness passes near the pump's rotating components
• Corroded or loose connector pins at the pump solenoid connector (C-shaped connector near pump body), common in machines with 8,000+ operating hours
• ECM power supply issues including degraded ground connections at the engine block grounding point
• Internal solenoid valve contamination from hydraulic fluid breakdown or debris in older machines with inconsistent fluid maintenance history

How to Troubleshoot and Fix Code E115

Step 1: Visual Inspection Begin by thoroughly inspecting the wiring harness from the ECM to the pump control solenoid. On used excavators, check for harness wear at the attachment point near the pump mounting bracket—this is a known wear point on the PC210LC-7. Look for abraded insulation, pinched wires, or oil-soaked connectors that indicate fluid infiltration.

Step 2: Electrical Testing Disconnect the solenoid connector and use a digital multimeter to measure coil resistance. The pump control solenoid should read between 10-30 ohms at room temperature. Next, check for voltage supply from the ECM with the key on: you should see battery voltage (approximately 24V) at the connector. Also test for proper ground continuity (less than 1 ohm resistance to chassis ground).

Step 3: Connector and Pin Inspection Even if electrical values seem correct, carefully inspect the connector pins for corrosion or microscopic cracks. On used machines, corrosion can create intermittent high-resistance connections that don't show up in static testing. Clean pins with electrical contact cleaner and apply dielectric grease before reconnecting.

Step 4: Solenoid Replacement Verification If the solenoid tests outside specifications, replace it with a genuine Komatsu part (part number 702-21-57400 or equivalent). After replacement, clear the code using Komatsu diagnostic software (KOMTRAX) or a compatible scan tool and perform a function test under load.

Step 5: System Verification Test all hydraulic functions under working conditions and monitor for code recurrence. If E115 returns immediately, suspect ECM internal driver circuit failure, which requires controller replacement or professional reprogramming.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Hydraulic system work involves high pressures and electrical voltages. Always consult the official Komatsu PC210LC-7 service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs can cause additional damage or safety hazards.