What is Hitachi ZW310-5A Fault Code 111705-8?

Fault Code 111705-8 on the Hitachi ZW310-5A wheel loader indicates a communication error or malfunction in the Engine Control Module (ECM) data link circuit, specifically related to Controller Area Network (CAN) bus communication issues between the engine controller and the machine's main electrical system.

This diagnostic trouble code (DTC) appears when the machine's ECM detects abnormal voltage levels, signal interruptions, or complete communication loss on the CAN bus network. The CAN bus serves as the central nervous system for modern excavators and wheel loaders, allowing critical systems like engine management, hydraulic controls, and instrument clusters to share real-time data. When this communication pathway fails, the machine cannot properly coordinate functions, leading to reduced performance or complete shutdown to prevent potential damage.

For the ZW310-5A specifically, this code is critical because it directly affects the machine's ability to regulate engine power output, monitor emission systems, and coordinate hydraulic pump controls with engine load demands.

Common Symptoms

• Check Engine Light or master warning lamp illuminated on the instrument cluster
• Engine derate mode activated, limiting power to 50-70% of normal output
• Intermittent loss of instrument panel readings (RPM, temperature, fuel level fluctuating or reading zero)
• Difficulty starting or unexpected engine shutdown during operation
• Hydraulic functions operating sluggishly or with delayed response due to improper engine-hydraulic coordination

Potential Causes

The most common technical causes for Code 111705-8 on used ZW310-5A machines include:

• CAN bus wiring harness damage from abrasion against frame components, particularly near the engine firewall or along the chassis rail where harnesses are exposed to vibration
• Corroded or loose connector pins at the ECM connector (C101) or main chassis harness junction points, especially on machines operated in corrosive environments
• Failed ECM internal communication module due to voltage spikes or age-related component degradation
• Poor grounding connections at engine block ground straps or chassis ground points causing signal interference
• Damaged termination resistors at CAN bus network endpoints (typically 120-ohm resistors)
• Water intrusion into ECM housing or wiring harnesses from damaged seals or improper maintenance

How to Troubleshoot and Fix Code 111705-8

Step 1: Visual Harness Inspection Begin with a thorough physical inspection of the CAN bus wiring harness from the ECM to all connected modules. On used excavators, focus on known rub points where the harness passes through bulkheads or near moving components. Look for abraded insulation, crushed wires, or signs of previous repairs with electrical tape. Inspect all connectors for corrosion, pushed-back pins, or moisture intrusion—these are extremely common on older machines.

Step 2: Electrical Testing Using a digital multimeter (DMM), measure CAN bus voltage with the key in the ON position (engine off). At the ECM connector, check pins designated for CAN-High and CAN-Low (consult Hitachi service manual for specific pin locations). You should read approximately 2.5V on each line with network at rest. Measure resistance between CAN-High and CAN-Low; you should read approximately 60 ohms (two 120-ohm terminating resistors in parallel). Readings significantly higher suggest open circuits or disconnected termination resistors.

Step 3: Check Ground Integrity Verify all engine and chassis ground connections are clean, tight, and free from corrosion. On used machines, ground straps often deteriorate from oil contamination and vibration. Measure voltage drop from ECM ground pin to battery negative—should be less than 0.1V with key on.

Step 4: Test with Diagnostic Software Connect Hitachi Dr.EX diagnostic software (or compatible tool) to isolate whether communication is completely lost or intermittent. Monitor live data while wiggling harnesses to identify intermittent connections. The software can also verify if termination resistors are functioning and identify which specific module is dropping off the network.

Step 5: Component Replacement If wiring and connections test good, the ECM itself may have internal failure. Before replacing this expensive component on a used machine, consider sending the ECM for bench testing and repair, which costs significantly less than new unit replacement.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual for your specific machine serial number and refer to qualified diesel technicians for complex electrical diagnostics. Improper electrical work can cause additional system damage or safety hazards.