What is XCMG XE750D Fault Code E361(1) SPN110 FMI15?

Fault Code E361(1) with SPN110 FMI15 indicates a critical engine coolant temperature sensor circuit malfunction with data validity issues on the XCMG XE750D excavator. Specifically, SPN 110 refers to the Engine Coolant Temperature (ECT) sensor, while FMI 15 signifies that the Electronic Control Module (ECM) is receiving data that falls outside acceptable parameters or contains implausible values.

This fault is particularly critical for the XE750D's engine management system because accurate coolant temperature readings directly affect fuel injection timing, turbocharger boost control, and engine protection protocols. When the ECM cannot trust the temperature data, it may force the engine into derate mode to prevent potential overheating damage, significantly reducing your machine's productivity on the jobsite.

Common Symptoms

When this fault code activates on your XCMG XE750D, operators typically experience:

• Engine warning light or check engine indicator illuminated on the instrument cluster
• Reduced engine power or automatic derate to approximately 70-80% of normal output
• Cooling fan running continuously at high speed, regardless of actual engine temperature
• Difficulty starting the engine, particularly in cold weather conditions
• Erratic temperature gauge readings that fluctuate abnormally or remain fixed at one position

Potential Causes

For used XCMG XE750D excavators, this fault typically stems from:

• Corroded or damaged wiring harness connectors at the ECT sensor, especially common near the engine block where vibration and heat cycles cause connector degradation
• Failed coolant temperature sensor due to age-related internal resistance drift or contamination from coolant additives
• Chafed or pinched sensor wiring along the harness routing points between the sensor and ECM, particularly where the harness passes near sharp metal edges or moving components
• Low coolant level causing air pockets around the sensor, leading to inaccurate readings
• Corroded sensor ground connection or poor ECM ground circuits
• ECM software calibration issues or internal ECM faults (less common)

How to Troubleshoot and Fix Code E361(1) SPN110 FMI15

Step 1: Visual Inspection and Connector Check

Begin by locating the Engine Coolant Temperature sensor on the engine block (typically on the cylinder head or upper radiator hose connection). Disconnect the sensor connector and carefully inspect both the sensor pins and harness connector for corrosion, bent pins, moisture intrusion, or heat damage. On used excavators, these connectors often show green corrosion or white mineral deposits. Clean connectors with electrical contact cleaner and apply dielectric grease before reconnecting.

Step 2: Sensor Resistance Testing

Using a digital multimeter (DMM), measure the resistance across the ECT sensor terminals with the sensor removed from the engine. At room temperature (approximately 20-25°C or 68-77°F), resistance should typically read between 2,000-3,000 ohms (consult XCMG specifications for exact values). Compare your reading against the manufacturer's temperature-resistance chart. If resistance is out of specification or reads open circuit (OL) or short circuit (near 0 ohms), replace the sensor.

Step 3: Wiring Harness Continuity and Ground Testing

With the sensor disconnected, check continuity from the sensor harness connector back to the ECM connector using your multimeter. There should be less than 5 ohms resistance on signal wires. Inspect the harness routing carefully for wear points, especially where it contacts the engine block, frame rails, or passes through bulkheads. Check the sensor ground circuit for proper continuity to chassis ground (should read less than 1 ohm). For used machines, pay special attention to harness sections near the turbocharger and exhaust manifold where heat damage is common.

Step 4: Coolant System Verification

Check the coolant level when the engine is cold. Low coolant can expose the sensor to air, causing erratic readings. Inspect for coolant leaks, air pockets, or contaminated coolant (oil mixing with coolant indicates head gasket issues). Bleed the cooling system per XCMG procedures if air is suspected.

Step 5: Advanced Diagnostics

If the sensor and wiring test properly, connect XCMG diagnostic software or a compatible J1939 scan tool to monitor live ECT sensor data. Compare the displayed temperature with an infrared thermometer reading of the actual engine temperature. A variance greater than 5-8°C (9-14°F) indicates sensor drift. Also check for other active codes that might affect coolant temperature readings, such as thermostat or cooling fan faults.

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Disclaimer: This guide provides general troubleshooting procedures for the XCMG XE750D fault code E361(1) SPN110 FMI15. Always consult the manufacturer's official service manual and safety procedures. If you're uncomfortable performing electrical diagnostics or working around hot engine components, contact a certified XCMG technician or qualified heavy equipment mechanic for professional assistance.