Hitachi ZW310-5A Fault Code 111701-9: Complete Diagnostic Guide

What is Hitachi ZW310-5A Fault Code 111701-9?

Fault Code 111701-9 indicates a malfunction in the Engine Control Module (ECM) communication circuit with the hydraulic pump control system. This diagnostic trouble code (DTC) specifically signals an intermittent or complete loss of data transmission between the engine ECM and the hydraulic pump controller, preventing proper coordination between engine output and hydraulic demand.

In the ZW310-5A wheel loader, this code directly affects the machine's ability to optimize fuel consumption and hydraulic performance through the load-sensing system. The ECM relies on continuous feedback from hydraulic sensors to adjust engine speed and torque, making this communication pathway critical for efficient operation and preventing component damage from improper loading.

Common Symptoms

When fault code 111701-9 is active, operators typically experience:

• Erratic hydraulic response with inconsistent boom, bucket, or steering speed regardless of control input
• Engine RPM fluctuation during loaded operations, particularly when multiple hydraulic functions operate simultaneously
• Warning light activation on the instrument cluster, often accompanied by reduced power mode
• Increased fuel consumption as the ECM defaults to conservative fuel mapping without hydraulic feedback
• Intermittent loss of power during high-demand operations like loading or lifting heavy materials

Potential Causes

The most common technical failures triggering this code in used ZW310-5A machines include:

• CAN bus wiring harness damage between ECM and hydraulic controller, particularly near the engine mounting points where vibration causes wire chafing
• Corroded or loose connector pins at the hydraulic pump controller module (known failure point after 5,000+ operating hours)
• Failed hydraulic pump pressure sensor providing corrupted data that disrupts communication protocol
• ECM software corruption or outdated firmware incompatible with hydraulic system calibration
• Damaged shielding on communication cables allowing electromagnetic interference from starter or alternator circuits

How to Troubleshoot and Fix Code 111701-9

Step 1: Visual Inspection of Communication Harness Begin by inspecting the CAN bus wiring harness routing from the ECM (located behind the operator cab) to the hydraulic pump controller. Check for physical damage, particularly where harnesses cross the engine frame rail—a common rub point on used machines. Use a digital multimeter to verify continuity across all pins with ignition off.

Step 2: Connector and Terminal Examination Disconnect the 8-pin connector at the hydraulic controller module. Inspect for green corrosion, bent pins, or moisture intrusion. Clean with electrical contact cleaner and apply dielectric grease. Measure resistance between communication pins (typically pins 3 and 6)—should read 60 ohms ±5 for proper CAN bus termination.

Step 3: Diagnostic Software Analysis Connect Hitachi Dr.EX diagnostic software to retrieve freeze frame data showing exact communication failure timing. Check for accompanying codes that might indicate voltage irregularities (below 11V or above 15V can corrupt data transmission). Test the hydraulic pressure sensor output voltage—should range 0.5-4.5V proportional to system pressure.

Step 4: Component Replacement Protocol For used excavators, replace the hydraulic controller connector first (most cost-effective solution). If code persists, the hydraulic pump controller module itself may require replacement—common after 8,000+ hours. Always clear codes and perform load test under actual working conditions before confirming repair.

Disclaimer: This guide provides general diagnostic information. Always consult the official Hitachi service manual and consider professional diagnostic services for complex electrical issues. Improper repairs may void warranties or create safety hazards.