Komatsu PC110-7 Fault Code E-19: Complete Diagnostic Guide

What is Komatsu PC110-7 Fault Code E-19?

Fault Code E-19 on the Komatsu PC110-7 indicates a malfunction in the hydraulic pump control system, specifically related to the pump flow control solenoid valve or its electrical circuit. This code signals that the Electronic Control Module (ECM) has detected an abnormal voltage or current condition in the solenoid that regulates hydraulic pump output.

The hydraulic pump control solenoid is critical on the PC110-7 because it directly manages hydraulic flow based on load demand. When this system fails, the excavator cannot optimize pump displacement, leading to reduced performance, increased fuel consumption, and potential overheating. For used machines, this fault often stems from electrical degradation rather than mechanical pump failure.

Common Symptoms

When Code E-19 is active, operators typically experience:

• Reduced hydraulic power across all functions (boom, arm, bucket, swing)
• Warning light illumination on the instrument panel with possible audible alarm
• Sluggish or inconsistent response during multi-function operations
• Increased engine RPM without corresponding hydraulic performance (pump not loading properly)
• Intermittent functionality that may temporarily resolve after restarting, indicating electrical connection issues

Potential Causes

The most common technical causes for E-19 on used PC110-7 excavators include:

• Solenoid valve coil failure due to heat exposure or internal short/open circuit
• Wiring harness damage at known rub points near the pump mounting area or along the undercarriage frame
• Connector corrosion at the solenoid plug, especially on machines operated in wet or corrosive environments
• ECM voltage supply issues including blown fuses or poor ground connections
• Previous repair quality on used equipment—improper connector sealing or aftermarket harness modifications

How to Troubleshoot and Fix Code E-19

Step 1: Visual Inspection
Begin with a thorough visual check of the pump control solenoid and its wiring harness. Look for obvious damage, chafing, oil contamination on connectors, or loose connections. On used PC110-7s, inspect where the harness passes near the hydraulic pump—this is a known wear point.

Step 2: Electrical Testing
Disconnect the solenoid connector and measure coil resistance using a digital multimeter. Komatsu specifications typically require 10-15 ohms (verify with service manual). Check for supply voltage (typically 12V) at the connector with ignition on. Measure ground continuity from the solenoid mounting point to battery negative.

Step 3: Advanced Diagnostics
Use Komatsu diagnostic software (KOMTRAX) or a compatible scan tool to monitor real-time solenoid command vs. actual current draw. Replace the solenoid valve if resistance is out of spec or if current draw is abnormal. For used machines, always apply dielectric grease to connectors during reassembly to prevent future corrosion.

Step 4: Post-Repair Verification
Clear the fault code, cycle the key, and perform a full hydraulic function test under load. Monitor for code recurrence, which may indicate ECM issues requiring dealer-level diagnostics.

---

Disclaimer: This guide provides general diagnostic information. Always consult the official Komatsu service manual for your specific serial number and consider professional technician assistance for complex electrical repairs on high-voltage systems.