Sumitomo SH200-5 Fault Code 1113: Complete Diagnostic Guide

What is Sumitomo SH200-5 Fault Code 1113?

Fault Code 1113 on the Sumitomo SH200-5 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 a voltage reading from the coolant temperature sensor that exceeds the manufacturer's specified range, typically above 4.8-5.0 volts.

The ECT sensor is a critical component in the SH200-5's Isuzu diesel engine management system. It monitors engine temperature and provides essential data for fuel injection timing, idle speed control, and engine protection protocols. When this code activates, the ECM may default to a predetermined temperature value, potentially causing improper fuel delivery and reduced operational efficiency.

Common Symptoms

When fault code 1113 is active, operators typically experience:

• Check Engine Light or warning lamp illuminated on the instrument panel
• Hard starting conditions, especially during cold weather operation
• Rough idle or irregular engine performance at operating temperature
• Poor fuel economy due to ECM operating in default temperature mode
• Engine derate or power reduction in some cases, particularly if multiple temperature-related faults occur simultaneously

Potential Causes

On used Sumitomo SH200-5 excavators, this high voltage code is commonly caused by:

• Open circuit in the ECT sensor wiring harness, often due to wire breakage or connector damage
• Failed coolant temperature sensor with internal open circuit condition
• Corroded or damaged connector pins at the sensor or ECM connection points—extremely common on machines with 5,000+ hours
• Wiring harness chafing near the engine block where heat and vibration cause insulation wear
• Poor ground connections at the sensor mounting point or ECM ground terminals
• ECM internal fault (rare but possible on older machines)

How to Troubleshoot and Fix Code 1113

Step 1: Visual Inspection Begin with a thorough physical examination of the ECT sensor located on the engine block near the thermostat housing. Inspect the wiring harness for visible damage, burns, or wear points where the wire contacts engine components. Check the connector for corrosion, bent pins, or moisture intrusion—common issues in used excavators operating in harsh environments.

Step 2: Electrical Testing Disconnect the ECT sensor connector and measure resistance across the sensor terminals using a digital multimeter. At room temperature (68°F/20°C), resistance should typically read 2,000-3,000 ohms. If the reading shows infinite resistance (OL), the sensor has failed internally and requires replacement.

Step 3: Circuit Verification With the sensor disconnected, check for voltage at the harness connector. You should measure approximately 5 volts reference voltage from the ECM on the signal wire with ignition on. If no voltage is present, trace the signal wire back to the ECM for breaks or damaged sections. On used SH200-5 machines, inspect areas where harnesses route near sharp edges or rotating components.

Step 4: Ground Path Testing Verify the sensor ground circuit by checking continuity between the ground terminal at the sensor connector and a known good chassis ground. Resistance should be less than 5 ohms. Clean all ground connections and apply dielectric grease to prevent future corrosion.

Step 5: Final Verification After repairs, clear the fault code using Sumitomo diagnostic software or a compatible J1939 scan tool. Run the engine through a complete heat cycle and monitor for code reoccurrence.

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Disclaimer: This guide provides general diagnostic information for the Sumitomo SH200-5. 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 further damage or safety hazards.