Hitachi ZH200LC-5A Fault Code 20113-2: Complete Diagnostic Guide

What is Hitachi ZH200LC-5A Fault Code 20113-2?

Fault Code 20113-2 indicates a malfunction in the engine coolant temperature sensor circuit, specifically detecting an abnormal voltage signal or intermittent connection in the cooling system monitoring circuit. This code is triggered when the Electronic Control Module (ECM) receives voltage readings outside the predetermined range for the coolant temperature sensor, typically between 0.5-4.5 volts.

This fault is critical for the ZH200LC-5A because the ECM relies on accurate coolant temperature data to optimize fuel injection timing, control engine warm-up cycles, and prevent overheating damage. Ignoring this code can lead to poor fuel economy, increased emissions, and potential engine damage from inadequate thermal management.

Common Symptoms

When fault code 20113-2 is active, operators typically experience:

• Check Engine Light or warning lamp illuminated on the instrument cluster
• Engine running in limp mode or derated performance, limiting maximum RPM to protect components
• Difficulty starting when the engine is cold, with extended cranking times
• Erratic temperature gauge readings or gauge stuck at minimum/maximum positions
• Increased fuel consumption and black smoke from exhaust due to improper fuel mapping
• Cooling fan running continuously at high speed regardless of actual engine temperature

Potential Causes

The most common technical causes for this fault code on used ZH200LC-5A excavators include:

• Coolant temperature sensor failure due to age-related degradation or internal short circuits
• Damaged or corroded wiring harness connections at the sensor plug, especially where harness routes near hot engine components
• Chafed wiring at known rub points along the engine block or frame rails (common on machines with 5,000+ hours)
• Corroded ECM connector pins from moisture intrusion in the electrical cabinet
• Failed ECM internal circuitry affecting the sensor input channel (rare but possible on high-hour machines)
• Improper sensor installation or wrong replacement part causing resistance mismatch

How to Troubleshoot and Fix Code 20113-2

Step 1: Visual Inspection Begin by inspecting the coolant temperature sensor located on the engine block near the thermostat housing. Check for physical damage, coolant leaks, or corrosion on the connector. On used excavators, carefully examine the wiring harness for signs of abrasion, especially where it contacts metal surfaces or heat shields.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor and measure its resistance. At 68°F (20°C), resistance should read approximately 2,000-3,000 ohms (consult service manual for exact specifications). Test harness continuity from sensor connector to ECM pins, checking for opens or shorts to ground.

Step 3: Voltage Signal Check With ignition on and sensor connected, backprobe the signal wire at the sensor connector. You should read approximately 5 volts with sensor disconnected (reference voltage from ECM), and 2-3 volts with sensor connected at operating temperature. Abnormal readings indicate ECM or harness issues.

Step 4: Connector Service Clean all connector terminals with electrical contact cleaner and apply dielectric grease to prevent future corrosion—critical for used machines operating in harsh environments.

Disclaimer: This guide provides general diagnostic procedures. Always consult the official Hitachi service manual for your specific machine serial number and consider professional diagnosis for complex electrical issues or if you lack proper diagnostic tools.