Sumitomo SH210-5 Fault Code 113: Complete Diagnostic Guide

What is Sumitomo SH210-5 Fault Code 113?

Fault Code 113 on the Sumitomo SH210-5 excavator indicates an Engine Coolant Temperature (ECT) Sensor Circuit High Voltage condition. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects an abnormally high voltage signal from the coolant temperature sensor circuit, typically above 4.8 volts.

The ECT sensor is a critical component that monitors engine operating temperature and sends real-time data to the ECM. This information directly affects fuel injection timing, idle speed control, and engine protection protocols. On used Sumitomo excavators, this code can lead to improper engine management, potentially causing overheating conditions or unnecessary derating that impacts jobsite productivity.

Common Symptoms

When Code 113 is active on your SH210-5, you may experience:

• Check Engine Light or warning lamp illuminated on the instrument panel
• Engine running in default mode with reduced power output or performance derate
• Erratic temperature gauge readings or gauge reading maximum temperature regardless of actual engine condition
• Hard starting or rough idle, especially during cold starts
• Cooling fan running continuously at high speed, even when engine is cold

Potential Causes

The most common technical reasons for Code 113 on used Sumitomo SH210-5 excavators include:

• Open circuit in the ECT sensor wiring harness (broken wire or poor connection)
• Failed coolant temperature sensor with internal open circuit condition
• Corroded or damaged connector pins at the sensor or ECM connection points—extremely common on older machines exposed to harsh environments
• Harness chafing where wiring passes near the engine block or frame rails (known wear point on this model)
• ECM internal fault affecting the sensor circuit input (less common but possible on high-hour machines)
• Damaged sensor threads causing poor ground connection through the engine block

How to Troubleshoot and Fix Code 113

Step 1: Visual Inspection Begin with a thorough inspection of the ECT sensor and its wiring harness. The sensor is typically located near the thermostat housing on the engine block. Check for physical damage, coolant leaks around the sensor, and inspect the connector for corrosion, bent pins, or moisture intrusion. On used excavators, pay special attention to harness routing—look for areas where the wire bundle contacts sharp edges or hot engine components.

Step 2: Electrical Testing Disconnect the ECT sensor connector and use a digital multimeter to measure resistance across the sensor terminals. At approximately 68°F (20°C), resistance should read between 2,000-3,000 ohms (consult your service manual for exact specifications). If the reading shows infinite resistance (OL), the sensor has an internal open circuit and requires replacement. Also inspect the sensor ground circuit for continuity to chassis ground.

Step 3: Wiring Harness Verification With the sensor disconnected, measure voltage at the harness connector from the ECM side. You should see approximately 5 volts reference voltage on the signal wire with ignition on. If voltage is present and correct, but the sensor tested bad, replace the sensor. If voltage is incorrect or absent, trace the harness back to the ECM, checking for breaks, shorts to power, or damaged insulation—critical on machines with 5,000+ hours.

Step 4: Advanced Diagnostics If sensor and wiring test properly, use Sumitomo diagnostic software or compatible scan tool to monitor live ECT data. Compare actual coolant temperature (use infrared thermometer) with displayed values. A significant discrepancy indicates ECM processing issues. Clear codes after repairs and perform a complete operational test cycle.

Disclaimer: This guide provides general diagnostic information for Sumitomo SH210-5 excavators. Always consult the manufacturer's service manual for model-specific procedures and specifications. If you're uncomfortable performing electrical diagnostics, contact a certified heavy equipment technician to prevent damage to expensive electronic components.