Hitachi ZX500LC-3 Fault Code 11910-2: Complete Diagnostic Guide

What is Hitachi ZX500LC-3 Fault Code 11910-2?

Fault Code 11910-2 indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically a data link error between the engine ECM and the machine's main controller. This code is part of Hitachi's proprietary diagnostic system and signals that critical operational data cannot be properly transmitted between control units.

This fault affects the CAN bus communication network, which is essential for coordinating engine performance with hydraulic systems, monitoring sensors, and displaying real-time machine data. On the ZX500LC-3, this communication failure can compromise fuel efficiency, power output regulation, and the operator's ability to monitor critical engine parameters through the dashboard display.

Common Symptoms

When Code 11910-2 is active, operators typically experience:

• Warning lights illuminated on the instrument cluster, particularly the engine malfunction indicator
• Intermittent or complete loss of engine parameter displays (RPM, coolant temperature, fuel level)
• Reduced engine power or derate mode activation as a protective measure
• Erratic hydraulic response due to improper engine-hydraulic system coordination
• Inability to access diagnostic information through the monitor panel

Potential Causes

The most common technical causes for this fault code include:

• Corroded or damaged CAN bus connectors between the engine ECM and main controller, especially at harness junction points
• Wiring harness chafing at known rub points near the engine mounting brackets or along the chassis frame
• Failed termination resistors in the CAN communication network (120-ohm resistors)
• ECM internal failure or corrupted software, more common in high-hour used machines
• Voltage supply issues to either control module due to failing relays or poor ground connections
• Water intrusion into connector housings from damaged seals or improper maintenance

How to Troubleshoot and Fix Code 11910-2

Step 1: Visual Inspection Begin by thoroughly inspecting all wiring harnesses between the engine ECM (located near the engine block) and the main controller. On used excavators, pay special attention to areas where harnesses pass through bulkheads or near moving components. Look for abraded insulation, corroded pins, or moisture in connectors.

Step 2: Electrical Testing Using a digital multimeter, verify proper voltage supply to both the engine ECM and main controller (typically 24V DC). Check CAN-High and CAN-Low signal wires for continuity and proper resistance. With the system powered off, measure resistance between CAN-High and CAN-Low terminals—you should read approximately 60 ohms (two 120-ohm termination resistors in parallel).

Step 3: Diagnostic Software Analysis Connect Hitachi Dr.EX diagnostic software or compatible scan tool to retrieve detailed fault data and monitor live CAN bus communication. Check for additional stored codes that might indicate the primary failure point. Clear codes and monitor for recurrence during operation.

Step 4: Component Replacement If testing reveals damaged connectors or harnesses, repair or replace affected sections using OEM-specification wiring and weatherproof connectors. For used machines, consider replacing aging termination resistors as preventive maintenance. If the ECM itself has failed, ensure replacement units are programmed with correct machine parameters.

---

Disclaimer: This guide provides general diagnostic information. Complex electrical issues should be diagnosed by qualified technicians with proper equipment. Always consult the official Hitachi service manual and follow safety protocols when working on heavy equipment.