Hitachi ZW220 Fault Code 11105-3: Complete Diagnostic Guide

What is Hitachi ZW220 Fault Code 11105-3?

Fault Code 11105-3 on the Hitachi ZW220 wheel loader indicates a malfunction in the hydraulic oil temperature sensor circuit, specifically detecting an abnormal voltage signal or open circuit condition. This code is generated when the Engine Control Module (ECM) receives voltage readings outside the expected range from the hydraulic oil temperature sensor, typically above 4.8V or below 0.2V.

The hydraulic oil temperature sensor plays a critical role in the ZW220's performance management system. It monitors hydraulic fluid temperature to prevent overheating, optimize hydraulic pump efficiency, and protect transmission components. When this sensor fails or sends erratic signals, the machine may enter a protective derate mode, limiting operational capacity and potentially causing costly downtime on job sites.

Common Symptoms

When fault code 11105-3 is active, operators typically experience:

• Warning light illumination on the instrument cluster, often accompanied by a hydraulic temperature warning icon
• Reduced hydraulic power or sluggish loader arm and bucket response
• Intermittent or constant derate mode, limiting engine RPM to protect the hydraulic system
• Inaccurate temperature gauge readings showing extremely high or low temperatures that don't match actual conditions
• ECM logging multiple instances of the fault, visible through diagnostic software

Potential Causes

The most common technical causes for code 11105-3 on used ZW220 machines include:

• Faulty hydraulic oil temperature sensor due to internal resistance drift or element failure (common after 5,000+ operating hours)
• Damaged or corroded wiring harness at connector points, particularly where the harness routes near the hydraulic tank
• Connector pin corrosion from moisture intrusion at the sensor plug (a known issue on machines operating in wet environments)
• Chafed wiring at harness rub points near the hydraulic pump mounting bracket
• ECM internal fault (rare, but possible on high-hour machines)
• Poor ground connection at the sensor mounting location due to rust or paint buildup

How to Troubleshoot and Fix Code 11105-3

Step 1: Visual Inspection Begin by locating the hydraulic oil temperature sensor on the hydraulic tank. Inspect the sensor connector for corrosion, bent pins, or moisture. Check the wiring harness along its entire route for abrasion, particularly where it contacts metal brackets or passes through grommets. On used excavators, pay special attention to areas where previous repairs may have compromised harness protection.

Step 2: Electrical Testing Disconnect the sensor and use a digital multimeter to measure resistance across the sensor terminals. At room temperature (20°C/68°F), resistance should typically read between 2,000-3,000 ohms (consult your service manual for exact specifications). Test the harness continuity from the sensor connector back to the ECM, checking for opens or shorts to ground. Measure supply voltage at the harness connector with ignition on—it should read approximately 5V.

Step 3: Component Replacement and Verification If sensor resistance is out of specification or harness testing reveals damage, replace the faulty component. Clean all connector pins with electrical contact cleaner and apply dielectric grease to prevent future corrosion. After repairs, clear the fault code using Hitachi diagnostic software (Dr.EX) or a compatible scan tool, then operate the machine through a full work cycle to verify the repair.

Professional Tip: Before replacing the sensor on used machines, verify proper hydraulic oil level and condition, as contaminated oil can accelerate sensor failure.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Hitachi service manual for your specific machine serial number and consider professional assistance for complex electrical diagnostics.