Sumitomo SH210-5 Fault Code 1113: Complete Diagnostic Guide

What is Sumitomo SH210-5 Fault Code 1113?

Fault Code 1113 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 4.8-4.9 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, engine warm-up cycles, and hydraulic system performance. On used Sumitomo excavators, this code can lead to improper engine management, reduced fuel efficiency, and potential overheating if the ECM receives false temperature readings.

Common Symptoms

When Code 1113 is active on your SH210-5, you may experience:

• Check Engine Light or warning lamp illuminated on the instrument panel
• Engine running in default "limp mode" with reduced power output and hydraulic response
• Hard starting conditions, especially during cold weather operation
• Cooling fan running continuously at high speed regardless of actual engine temperature
• Inaccurate temperature gauge readings showing abnormally cold temperatures (often below normal operating range)

Potential Causes

The most common technical reasons for Code 1113 on used Sumitomo SH210-5 excavators include:

• Open circuit in the ECT sensor wiring harness due to wire breaks or connector damage
• Failed ECT sensor with internal open circuit (common on machines with 8,000+ operating hours)
• Corroded or loose connector pins at the sensor or ECM connection points
• Wiring harness chafing near the engine block mounting points—a known wear point on this model
• Poor ground connection at the sensor mounting location due to thread corrosion or gasket deterioration
• ECM internal fault (rare, but possible on machines with electrical system history)

How to Troubleshoot and Fix Code 1113

Step 1: Visual Inspection Begin with the engine cool. Locate the ECT sensor (typically installed in the engine block coolant passage near the thermostat housing). Inspect the sensor connector for corrosion, bent pins, moisture intrusion, or physical damage. Check the wiring harness for signs of rubbing, particularly where it routes near the engine mount brackets—a common failure point on used SH210-5 models.

Step 2: Electrical Testing Disconnect the ECT sensor connector. Using a digital multimeter, measure the resistance across the sensor terminals. At room temperature (68°F/20°C), resistance should typically read 2,000-3,000 ohms (consult your service manual for exact specifications). If the reading shows infinite resistance (open circuit), the sensor has failed internally and requires replacement.

Step 3: Circuit Voltage Check With the sensor disconnected and ignition ON (engine off), measure voltage at the harness connector (ECM side). You should see approximately 5 volts reference voltage from the ECM. If voltage reads near battery voltage (12V+) or 0V, trace the wiring for short circuits or breaks between the sensor and ECM.

Step 4: Harness Continuity Test Check continuity between the sensor connector and ECM pins using wiring diagrams. Pay special attention to ground circuit integrity. On used excavators, corrosion at grounding points frequently causes high-resistance conditions that mimic sensor failures.

Step 5: Repair and Clear Code Replace faulty components (sensor, damaged wiring, or corroded connectors). Apply dielectric grease to connector pins before reassembly to prevent future corrosion. Clear the fault code using Sumitomo diagnostic software or compatible scan tool, then monitor for code recurrence during a full heat cycle.

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Disclaimer: This guide provides general diagnostic information for Sumitomo SH210-5 excavators. Always consult the manufacturer's service manual and safety procedures. For complex electrical issues or if you're uncomfortable performing these diagnostics, contact a certified Sumitomo technician or qualified heavy equipment mechanic.