What is Hitachi ZW310-5A Fault Code 111705-11?

Fault Code 111705-11 on the Hitachi ZW310-5A wheel loader indicates a communication error between the Engine Control Module (ECM) and the Transmission Control Unit (TCU), specifically signaling an abnormal CAN bus data transmission failure. This diagnostic trouble code (DTC) means the two critical control systems cannot properly exchange operational data, which is essential for coordinated power delivery and transmission shifting.

This fault code is particularly critical on the ZW310-5A because this model relies on integrated electronic control for optimal fuel efficiency and hydraulic performance. When the ECM and TCU lose communication, the machine typically enters a protective derate mode to prevent potential damage, severely limiting productivity on job sites.

Common Symptoms

When fault code 111705-11 is active, operators typically experience:

• Warning light illumination on the instrument cluster, often accompanied by a transmission malfunction indicator
• Reduced engine power or limited maximum RPM as the system enters protective mode
• Erratic or delayed transmission shifting, including failure to shift beyond certain gears
• Inability to engage certain drive modes (forward/reverse hesitation or complete loss of response)
• Intermittent loss of power that may temporarily resolve after key cycling, then return

Potential Causes

The most common technical causes for this code on used ZW310-5A machines include:

• CAN bus wiring harness damage at known rub points near the transmission mounting area where vibration causes insulation wear
• Corroded or loose connector pins at the ECM or TCU harness connections, especially on machines with high exposure to moisture or salt
• Failed CAN bus termination resistor (120-ohm resistor) causing signal reflection and data corruption
• ECM or TCU internal failure, though less common than wiring issues on used equipment
• Voltage supply problems to either control module, often traced to poor ground connections or aged battery cables
• Aftermarket component interference if non-OEM parts have been installed that affect electrical systems

How to Troubleshoot and Fix Code 111705-11

Step 1: Perform Visual Inspection Begin by examining all wiring harnesses between the ECM (typically located near the engine) and TCU (mounted on or near the transmission). On used excavators, pay special attention to harness routing where cables contact frame members or pass near the transmission bellhousing. Look for abraded insulation, pinched wires, or evidence of previous repairs.

Step 2: Check Connector Integrity Disconnect the main harness connectors at both the ECM and TCU. Inspect pins for corrosion (green/white deposits), bent contacts, or moisture intrusion. Clean connectors with electrical contact cleaner and apply dielectric grease before reconnection. This simple step resolves approximately 40% of communication faults on older machines.

Step 3: Test CAN Bus Continuity and Resistance Using a digital multimeter, check for continuity on the CAN-High and CAN-Low wires between ECM and TCU (consult your service manual for specific pin locations). With both modules disconnected, measure resistance between CAN-High and CAN-Low; you should read approximately 60 ohms (indicating two 120-ohm termination resistors in parallel). Readings significantly higher suggest an open circuit; lower readings may indicate a short.

Step 4: Verify Power Supply and Grounds Check that both control modules receive proper battery voltage (typically 24V on the ZW310-5A) at their power supply pins. More importantly, verify ground connections are clean and tight, as poor grounds are a leading cause of intermittent communication failures on used equipment.

Step 5: Utilize Diagnostic Software Connect Hitachi diagnostic software (Dr.EX or equivalent) to read live CAN bus data and monitor communication status. This will help identify whether the fault is intermittent and which module is failing to transmit. Check for additional stored codes that might indicate the primary failure point.

Step 6: Component Replacement If wiring and connections check out, the issue likely resides in a control module. Before replacing expensive components on used machinery, consider having modules bench-tested by a qualified electronics repair facility, as ECM and TCU rebuilding is often more cost-effective than new unit replacement.

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Disclaimer: This guide provides general troubleshooting information for fault code 111705-11. Always consult your Hitachi service manual for model-specific procedures and safety precautions. For complex electrical diagnostics or if you're uncomfortable working with control systems, seek assistance from a certified Hitachi technician or qualified heavy equipment electrician.