Sumitomo SH360HD-6 Fault Code 113: Complete Diagnostic Guide

What is Sumitomo SH360HD-6 Fault Code 113?

Fault Code 113 on the Sumitomo SH360HD-6 excavator indicates a malfunction in the engine coolant temperature sensor circuit or an abnormal coolant temperature reading detected by the Electronic Control Module (ECM). This code specifically points to either the coolant temperature sensor itself, the associated wiring harness, or a signal processing issue within the ECM.

The engine coolant temperature sensor plays a critical role in the SH360HD-6's diesel engine management system. It provides real-time temperature data that the ECM uses to optimize fuel injection timing, regulate engine warm-up cycles, and prevent overheating conditions. When this sensor fails or provides erratic readings, the excavator's performance and longevity are immediately compromised.

Common Symptoms

When Code 113 is active on your Sumitomo SH360HD-6, operators typically experience:

• Check Engine Light or malfunction indicator illuminated on the dashboard
• Erratic temperature gauge readings that fluctuate unexpectedly or show incorrect temperatures
• Hard starting conditions, especially during cold weather operation
• Poor fuel economy and black smoke from the exhaust due to improper fuel mixture
• Engine derate mode activation, limiting power output to protect the engine from potential damage

Potential Causes

The most common technical causes for Code 113 on used SH360HD-6 excavators include:

• Faulty coolant temperature sensor due to age-related degradation or internal element failure
• Corroded or loose connector pins at the sensor plug, common in machines exposed to harsh environments
• Damaged wiring harness between the sensor and ECM, particularly at known rub points near the engine block
• Low coolant level causing intermittent sensor exposure and inaccurate readings
• Defective ECM (rare) with internal circuit board issues affecting signal processing
• Aftermarket sensor incompatibility if previous repairs used non-OEM components

How to Troubleshoot and Fix Code 113

Step 1: Visual Inspection Begin by inspecting the coolant temperature sensor location (typically on the engine block or thermostat housing). Check for physical damage, coolant leaks, and verify proper coolant level. On used excavators, examine the wiring harness for abrasion points where it contacts the engine or frame.

Step 2: Electrical Testing Disconnect the sensor connector and inspect for corrosion or bent pins—clean with electrical contact cleaner if necessary. Using a digital multimeter, measure the sensor's resistance at ambient temperature (typically 2,000-3,000 ohms at 68°F). Compare readings against Sumitomo specifications.

Step 3: Circuit Verification Check voltage supply from the ECM (usually 5V reference voltage) at the connector with ignition on. Test continuity through the harness back to the ECM. Resistance should be less than 5 ohms with no shorts to ground.

Step 4: Component Replacement If sensor readings fall outside specifications or harness damage is evident, replace the faulty component with OEM Sumitomo parts. For used excavators, always replace the connector and apply dielectric grease to prevent future corrosion.

Step 5: Clear Code and Verify After repairs, clear the fault code using Sumitomo diagnostic software or a compatible scan tool. Run the engine through full temperature cycles to confirm proper operation.

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Disclaimer: This guide provides general diagnostic information. Complex electrical issues or internal ECM problems should be addressed by certified Sumitomo technicians with proper diagnostic equipment.