What is XCMG XE750D Fault Code 2610-6 SPN3663 FMI6?

Fault Code 2610-6 (SPN 3663, FMI 6) indicates a calibration or data issue with the Engine Variable Geometry Turbocharger (VGT) Actuator or its control circuit. Specifically, FMI 6 denotes that the Electronic Control Module (ECM) has detected data that is above normal or out of acceptable range for the VGT actuator position sensor.

This code affects the variable geometry turbocharger system, which is critical for optimizing boost pressure, fuel efficiency, and emissions control on the XE750D's diesel engine. The VGT actuator adjusts internal vanes within the turbocharger to regulate exhaust gas flow and boost response. When the ECM receives incorrect position feedback, it cannot properly manage engine performance, potentially triggering engine derate modes to prevent damage.

For a large excavator like the XCMG XE750D, proper turbocharger function is essential for maintaining hydraulic system performance and operational efficiency under heavy loads.

Common Symptoms

• Check Engine Light (CEL) or malfunction indicator lamp illuminated on the instrument cluster
• Reduced engine power or noticeable loss of hydraulic performance during digging or lifting operations
• Black smoke from exhaust due to improper air-fuel ratio management
• Engine derate mode activated, limiting maximum RPM to protect the engine
• Poor throttle response or hesitation during acceleration under load

Potential Causes

• VGT actuator position sensor failure due to heat exposure or internal wear (common in high-hour used machines)
• Damaged or corroded wiring harness between the ECM and VGT actuator—check for harness rub points near the turbocharger mounting area
• Carbon buildup on VGT vanes causing mechanical binding and inaccurate position readings
• Faulty ECM calibration or corrupted software parameters (especially after previous repairs or ECM replacement)
• Poor electrical ground connection at the actuator or ECM causing voltage reference errors
• Water intrusion into connectors from damaged seals or improper maintenance on used equipment

How to Troubleshoot and Fix Code 2610-6 SPN3663 FMI6

Step 1: Visual Inspection Begin with a thorough inspection of the VGT actuator wiring harness from the turbocharger to the ECM. On used excavators, check for wire chafing, corrosion on connector pins, or heat damage near the exhaust manifold. Clean all connectors with electrical contact cleaner and verify proper sealing.

Step 2: Test Actuator Signal and Power Using a digital multimeter, verify the reference voltage (typically 5V) and ground signal at the VGT actuator connector with the ignition on, engine off. Check the position sensor feedback voltage while manually moving the actuator arm (if accessible). Compare readings to XCMG specifications—values outside 0.5-4.5V typically indicate sensor failure.

Step 3: Perform Functional Test Connect XCMG diagnostic software or compatible J1939 scan tool to command the VGT actuator through its full range. Listen for smooth motor operation and verify position feedback matches commanded values. Erratic readings or mechanical grinding sounds indicate actuator replacement is needed.

Step 4: Check for Mechanical Binding Remove the turbocharger inlet and inspect VGT vanes for carbon deposits or seized movement. Used excavators often accumulate carbon buildup that prevents proper vane operation. Clean with appropriate solvent or consider turbocharger service if severely clogged.

Step 5: Clear Code and Test After repairs, clear fault codes, perform a VGT relearn procedure using diagnostic software, and run the machine under load to verify proper operation.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the XCMG service manual for your specific machine serial number and consider professional diagnostic assistance for complex electrical or turbocharger system repairs.