Hitachi ZX850-3 Fault Code 14105-2: Complete Diagnostic Guide

What is Hitachi ZX850-3 Fault Code 14105-2?

Fault Code 14105-2 indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically related to a CAN (Controller Area Network) bus communication error or timeout condition. This code triggers when the main ECM loses proper data transmission with peripheral control modules or sensors within the machine's electronic network.

In the Hitachi ZX850-3, this fault affects the integrated control system that manages engine performance, hydraulic functions, and machine diagnostics. The CAN bus serves as the central nervous system for electronic communication, and any disruption can compromise real-time data exchange between the engine ECM, monitor controller, and hydraulic control units. This is critical because the ZX850-3 relies on continuous electronic feedback to optimize fuel injection timing, hydraulic response, and emission controls.

Common Symptoms

When Code 14105-2 is active, operators typically experience:

• Warning lights illuminated on the instrument cluster, particularly the engine malfunction or system error indicators
• Intermittent loss of monitor display functions, including blank screens or frozen gauge readings
• Reduced engine power or derate mode activation, limiting machine performance to protect components
• Erratic hydraulic response or delayed control inputs due to communication lag
• Inability to access diagnostic information through the standard monitor interface

Potential Causes

The most common technical causes for this fault code in used ZX850-3 excavators include:

• Corroded or damaged CAN bus connectors, particularly at the ECM harness connection points behind the operator cab
• Wiring harness chafing at known rub points near the engine mounting brackets and along the main boom pivot area
• Failed termination resistors within the CAN network, causing signal reflection and data corruption
• ECM power supply issues, including poor ground connections or voltage fluctuations from aging battery cables
• Water intrusion into sealed connectors, common in machines operating in wet or humid environments
• Faulty monitor controller unit or peripheral module creating network conflicts

How to Troubleshoot and Fix Code 14105-2

Step 1: Visual Inspection Begin by thoroughly inspecting all wiring harnesses along the CAN bus network. Focus on connectors at the ECM (located under the right-hand side panel), monitor controller, and junction boxes. Look for corrosion, bent pins, or moisture inside connector housings. On used excavators, check for harness wear at frame contact points and cable ties that may have loosened over time.

Step 2: Electrical Testing Using a digital multimeter, verify proper voltage supply to the ECM (typically 24V DC). Check CAN-High and CAN-Low signal wires (usually yellow and green) for continuity and proper resistance. Between CAN-High and CAN-Low, you should measure approximately 60 ohms with the key off, indicating proper termination resistor function. Use Hitachi Dr.EX diagnostic software to monitor live CAN bus traffic and identify which module is failing to communicate.

Step 3: Component Testing and Repair If wiring checks pass, test termination resistors at network endpoints. Replace any corroded connectors with OEM-spec sealed units. For persistent issues, perform an ECM power cycle by disconnecting batteries for 10 minutes. In used machines, consider replacing the entire engine harness section if multiple rub points show wear, as intermittent shorts are difficult to isolate.

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 may cause additional system damage.