Sumitomo SH200-5 Fault Code 0113: Complete Diagnostic Guide

What is Sumitomo SH200-5 Fault Code 0113?

Fault Code 0113 on the Sumitomo SH200-5 excavator indicates an Engine Coolant Temperature (ECT) Sensor Circuit High Voltage condition. This code triggers when the Electronic Control Module (ECM) detects voltage readings from the coolant temperature sensor that exceed the manufacturer's specified upper threshold, typically above 4.8-4.9 volts in the signal circuit.

The ECT sensor is critical for this excavator's performance because it directly affects engine protection systems, fuel injection timing, and hydraulic oil temperature management. When the ECM receives abnormally high voltage signals, it assumes the coolant temperature is extremely low (since these sensors use negative temperature coefficient resistance), which can cause improper engine management, inefficient combustion, and potential component damage if left unaddressed.

Common Symptoms

When Code 0113 is active on your SH200-5, you may experience:

• Check Engine Light illuminated on the instrument cluster with reduced engine performance
• Hard starting conditions, especially when the engine is actually warm
• Poor fuel economy and black smoke from the exhaust due to incorrect fuel mapping
• Engine running in limp mode with power derate to protect components
• Erratic temperature gauge readings or gauge showing constant cold temperature regardless of actual engine temperature

Potential Causes

The most common technical causes for Code 0113 on used Sumitomo SH200-5 excavators include:

• Open circuit in the ECT sensor wiring harness, particularly where the harness routes near the engine block and experiences heat cycling
• Failed ECT sensor with internal open circuit (common after 5,000+ operating hours)
• Corroded or damaged connector pins at the sensor or ECM connection points—especially problematic in machines with water or coolant leak history
• Chafed wiring at known rub points near the thermostat housing or along the valve cover
• Poor ground connection at the sensor return circuit or ECM ground points
• ECM internal fault (rare, but possible in high-hour machines with electrical system issues)

How to Troubleshoot and Fix Code 0113

Step 1: Visual Inspection Begin with the engine cold. Locate the ECT sensor (typically installed near the thermostat housing on the SH200-5). Inspect the sensor connector for corrosion, bent pins, moisture intrusion, or physical damage. On used excavators, check for coolant residue around the sensor threads indicating previous leaks that may have damaged the connector. Examine the entire wiring harness for chafing, especially where it contacts metal surfaces or passes through grommets.

Step 2: Electrical Testing Disconnect the ECT sensor connector. Using a digital multimeter (DMM), 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 (OL), the sensor has an internal open circuit and requires replacement. Next, measure voltage at the harness connector (sensor disconnected, ignition ON): you should see approximately 5 volts on the signal wire. If voltage reads near battery voltage (12V+), there's a short to power in the harness.

Step 3: Signal Circuit and Ground Testing With the sensor still disconnected and ignition ON, use your DMM to check for continuity between the sensor signal wire and ground—there should be no continuity (infinite resistance). Any continuity indicates a short to ground. Check the sensor ground circuit for continuity to ECM ground and battery negative—it should show less than 1 ohm resistance. For used machines, remove any corrosion from ground connection points using electrical contact cleaner and a wire brush.

Step 4: Component Replacement and Verification If testing confirms sensor failure, replace the ECT sensor using OEM or high-quality aftermarket parts with proper thread sealant (non-Teflon based to prevent sensor contamination). If wiring issues were found, repair or replace the affected harness section using proper gauge wire, heat-shrink connectors, and protective loom. After repairs, clear the fault code using Sumitomo diagnostic software or a compatible scan tool, run the engine through a complete warm-up cycle, and verify the code does not return.

Disclaimer: This guide provides general diagnostic information for experienced technicians. Always consult the official Sumitomo service manual for your specific machine serial number range. If you're uncomfortable performing electrical diagnostics, contact a certified Sumitomo dealer or qualified heavy equipment technician to prevent further damage to electrical systems.