Hitachi ZX850LC-3 Fault Code 14105-2: Complete Diagnostic Guide

What is Hitachi ZX850LC-3 Fault Code 14105-2?

Fault Code 14105-2 indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically a CAN (Controller Area Network) bus communication error between the engine controller and the machine's main monitoring system.

This code triggers when the ECM detects an abnormal signal or complete loss of communication on the CAN data link. For the ZX850LC-3, this is critical because the CAN bus coordinates communication between multiple control systems including engine management, hydraulic controls, and the operator display. Without proper CAN communication, the machine cannot properly regulate engine performance, monitor critical parameters, or display accurate operational data to the operator.

The Isuzu engine used in this model relies heavily on integrated electronic control, making CAN bus integrity essential for optimal performance and diagnostics.

Common Symptoms

When fault code 14105-2 is active, operators typically experience:

• Intermittent or complete loss of monitor display information (engine RPM, temperature, pressure readings blank or frozen)
• Engine derate or limited power mode as a protective measure
• Multiple simultaneous fault codes appearing on the display panel
• Warning lights illuminating on the instrument cluster without clear cause
• Inability to access diagnostic functions through the monitor panel

Potential Causes

The most common technical causes for this fault code on used ZX850LC-3 excavators include:

• Corroded or damaged CAN bus connectors at the ECM or junction points (especially common in high-hour machines exposed to moisture)
• Wiring harness damage from rubbing against frame components near the engine mounting area or along the right-hand chassis rail
• Failed termination resistors in the CAN network (typically 120-ohm resistors at network endpoints)
• ECM power supply issues including poor ground connections or voltage fluctuations
• Water intrusion into the main harness connector behind the operator cab
• ECM internal failure (less common but possible in high-hour units)

How to Troubleshoot and Fix Code 14105-2

Step 1: Visual Inspection Begin by thoroughly inspecting all wiring harnesses between the ECM (located on the right side of the engine) and the main monitor. Look for obvious damage, chafing, or connector corrosion. On used excavators, pay special attention to harness routing near the engine mounts where vibration causes wear.

Step 2: Check CAN Bus Continuity and Resistance Using a digital multimeter, disconnect the battery and measure resistance between the CAN-High and CAN-Low terminals at the ECM connector. You should read approximately 60 ohms (two 120-ohm termination resistors in parallel). Readings significantly higher suggest an open circuit; lower readings may indicate a short.

Step 3: Verify Power and Ground Circuits Check that the ECM receives proper battery voltage (24V nominal) and has a solid ground connection. Measure voltage drop across ground circuits—anything above 0.2V indicates resistance requiring correction. Clean all ground points thoroughly.

Step 4: Test with Diagnostic Software Connect Hitachi Dr.EX diagnostic software or equivalent to monitor real-time CAN bus activity. This can identify whether communication failures are intermittent or constant, and which specific modules are affected.

Step 5: Component Replacement If wiring and connections test good, suspect the ECM itself. Before replacing, verify the issue isn't with the monitor display unit by checking if other CAN-connected systems function properly.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs can cause additional system damage.