What is XCMG XE750D Fault Code E1365(2) SPN3516 FMI16?

Fault Code E1365(2) with SPN3516 FMI16 indicates a data issue with the Engine Control Module (ECM) detecting invalid or out-of-range data from the aftertreatment system's Diesel Exhaust Fluid (DEF) pump control circuit. Specifically, SPN 3516 refers to the DEF pump actuator, while FMI 16 signals that the ECM is receiving data that's valid but not responding correctly or within expected parameters.

This code is critical for the XCMG XE750D because it directly affects the Selective Catalytic Reduction (SCR) system's ability to inject DEF properly. When this system malfunctions, the excavator may enter engine derate mode to comply with emissions regulations, significantly reducing jobsite productivity and potentially causing expensive downtime on used machines where DEF system components may already be compromised.

Common Symptoms

• Yellow or amber warning light illuminated on the instrument cluster, specifically related to emissions or aftertreatment systems
• Engine power derate occurring after a grace period, limiting machine to 50-70% normal operating capacity
• DEF consumption abnormalities – either no DEF usage or excessive consumption patterns
• Intermittent rough idling or slight performance hesitation during hydraulic operations
• Diagnostic display message indicating SCR system malfunction or DEF quality concerns

Potential Causes

On used XCMG XE750D excavators, this fault typically stems from several age-related issues:

• DEF pump actuator failure due to crystallized urea buildup inside the pump mechanism (common after 4,000+ hours)
• Corroded or damaged wiring harness connections at the DEF pump connector, particularly where the harness routes near the fuel tank mounting brackets
• Failed DEF pump relay or control module within the aftertreatment system control unit
• Contaminated DEF fluid causing sensor feedback errors (especially in machines with unknown service history)
• ECM software calibration issues requiring updates to match current emission standards
• Faulty DEF temperature or pressure sensors sending conflicting data to the ECM

How to Troubleshoot and Fix Code E1365(2) SPN3516 FMI16

Step 1: Visual Inspection and Connection Check Begin by inspecting the DEF pump wiring harness for physical damage, corrosion, or chafing. On used excavators, check where the harness passes through frame brackets near the DEF tank. Disconnect the DEF pump connector and inspect pins for corrosion or bent terminals. Clean connections with electrical contact cleaner and dielectric grease.

Step 2: DEF System Component Testing Using a digital multimeter, check the DEF pump actuator resistance (typically 2-6 ohms between terminals). Verify supply voltage at the pump connector with ignition on (should read 12V). Use XCMG diagnostic software or a compatible J1939 scan tool to monitor live DEF pump command data versus actual pump feedback.

Step 3: DEF Quality and Pump Function Verification Test DEF fluid concentration with a refractometer (should read 32.5% urea). Drain and inspect DEF from the tank for contamination or crystallization. For used machines, consider removing the DEF pump assembly to inspect for internal crystallization blocking the actuator mechanism. If crystallization is present, flush the entire system and replace the pump.

Step 4: ECM Communication and Software Check Verify ECM firmware is current using manufacturer diagnostic tools. Check for related fault codes that might indicate broader aftertreatment system issues. Clear codes and perform a DEF pump relearn procedure using the diagnostic software.

Disclaimer: This guide provides general troubleshooting information. Always consult the official XCMG service manual for your specific machine serial number and software version. If you're uncomfortable performing electrical diagnostics or working with pressurized DEF systems, contact a certified XCMG technician or heavy equipment diesel specialist.