Sumitomo SH210LC-5LR Fault Code 113: Complete Diagnostic Guide

What is Sumitomo SH210LC-5LR Fault Code 113?

Fault Code 113 on the Sumitomo SH210LC-5LR indicates a malfunction in the Engine Coolant Temperature (ECT) sensor circuit or an abnormal coolant temperature reading detected by the Electronic Control Module (ECM). This code triggers when the engine control system receives voltage signals outside the expected range from the coolant temperature sensor, typically indicating either sensor failure, wiring issues, or actual overheating conditions.

The ECT sensor plays a critical role in the SH210LC-5LR's engine management system by monitoring coolant temperature and sending voltage signals to the ECM. This data directly affects fuel injection timing, engine warm-up cycles, and protective shutdown protocols. On used excavators, this sensor circuit is particularly vulnerable to degradation from years of thermal cycling and exposure to vibration.

Common Symptoms

When Code 113 is active, operators typically experience:

• Check Engine Light illuminated on the instrument panel with possible temperature warning lamp activation
• Hard starting conditions or extended cranking, especially during cold starts when the ECM cannot properly adjust fuel delivery
• Erratic engine idle or rough running as the ECM defaults to fail-safe fuel mapping
• Reduced engine power or derate mode engagement to prevent potential overheating damage
• Inaccurate temperature gauge readings showing unrealistic high or low coolant temperatures

Potential Causes

The most common technical causes for Code 113 on used SH210LC-5LR excavators include:

• ECT sensor failure due to internal resistance drift or element contamination from old coolant
• Corroded or loose connector pins at the sensor harness connection point near the thermostat housing
• Damaged sensor wiring from rubbing against the engine block or heat exposure from exhaust components
• Shorted or open circuits in the harness between the sensor and ECM, common at flex points
• Low coolant levels causing the sensor to read air temperature instead of liquid coolant
• Failed ECM (rare) with corrupted temperature input circuitry

How to Troubleshoot and Fix Code 113

Step 1: Visual Inspection Begin by inspecting the ECT sensor located near the thermostat housing on the engine block. Check the connector for corrosion, moisture intrusion, or damaged pins—common issues on used machines. Examine the wiring harness for chafing, especially where it routes near sharp edges or moving components.

Step 2: Sensor Resistance Testing Disconnect the sensor and measure resistance using a digital multimeter. At 68°F (20°C), resistance should typically read 2,000-3,000 ohms (consult service manual for exact specifications). Compare readings at different temperatures—resistance should decrease smoothly as temperature increases. Erratic or out-of-spec readings confirm sensor replacement is needed.

Step 3: Circuit Voltage Check With the sensor disconnected and ignition on, measure voltage at the harness connector. You should see approximately 5 volts reference voltage from the ECM. No voltage indicates a wiring break or ECM issue. Check for continuity between sensor ground and chassis ground.

Step 4: Verify Coolant Condition Inspect coolant level and quality. Old, contaminated coolant can damage the sensor element. On used excavators, flushing the cooling system and replacing the sensor together often prevents recurring codes.

Step 5: Clear Code and Test After repairs, use Sumitomo diagnostic software or a compatible scan tool to clear the fault code. Run the engine through heat cycles while monitoring live data to confirm proper sensor operation and temperature readings.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Sumitomo service manual for your specific machine serial number and consider professional technician assistance for complex electrical diagnostics or if unfamiliar with high-voltage systems.