What is XCMG XE750D Fault Code E1190(3) SPN5562 FMI1?

Fault Code E1190(3) SPN5562 FMI1 indicates a data validity issue with the Diesel Exhaust Fluid (DEF) temperature sensor in the aftertreatment system. Specifically, SPN 5562 refers to the Aftertreatment 1 Diesel Exhaust Fluid Temperature, while FMI 1 signals that the data received from this sensor is valid but outside the normal operating range (above normal).

This fault is critical for the XCMG XE750D's Selective Catalytic Reduction (SCR) system, which relies on accurate DEF temperature readings to properly inject and vaporize the diesel exhaust fluid. When the Engine Control Module (ECM) detects abnormal temperature data, it cannot optimize emissions control, potentially triggering engine derate modes to protect the aftertreatment system and ensure EPA compliance.

Common Symptoms

• Amber or red warning light illuminated on the dashboard indicating an emissions system fault
• Engine power derate (reduced horsepower) after a predetermined time period if the fault persists
• DEF system malfunction messages displayed on the instrument cluster
• Increased diesel exhaust fluid consumption or refusal to inject DEF properly
• Difficulty passing emissions tests or triggering environmental protection protocols

Potential Causes

The most common technical causes for this fault code on used XCMG XE750D excavators include:

• Failed DEF temperature sensor due to crystallized urea deposits or internal sensor degradation
• Corroded or damaged wiring harness connections at the DEF tank or dosing module (common wear point on high-hour machines)
• DEF tank heater malfunction causing actual temperature irregularities that trigger valid but out-of-range readings
• Contaminated or degraded diesel exhaust fluid affecting sensor accuracy and system performance
• ECM calibration issues or software glitches misinterpreting valid sensor data
• Physical damage to DEF lines or tank from previous repairs or impact damage on used equipment

How to Troubleshoot and Fix Code E1190(3) SPN5562 FMI1

Step 1: Connect Diagnostic Software Use XCMG-compatible diagnostic software or a quality J1939 scanner to read live data from the DEF temperature sensor. Monitor real-time temperature readings and compare them to ambient temperature and expected operating values (typically -40°F to 185°F).

Step 2: Inspect DEF System Components Physically inspect the DEF tank, temperature sensor, and associated wiring harness for corrosion, crystallized urea buildup, or physical damage. On used excavators, pay special attention to harness routing near the frame rails where vibration and rubbing commonly occur. Check all connector pins for corrosion or bent terminals.

Step 3: Test Sensor and Circuits Using a digital multimeter, check the DEF temperature sensor resistance according to XCMG specifications (typically 2,000-3,000 ohms at room temperature for NTC-type sensors). Verify supply voltage (usually 5V reference) and ground continuity at the sensor connector with the harness disconnected.

Step 4: Verify DEF Quality and Tank Heater Test the DEF fluid with a refractometer to ensure proper concentration (32.5% urea). Check the DEF tank heater operation with a multimeter for proper resistance and verify it activates in cold conditions. Contaminated or old DEF can cause legitimate temperature anomalies.

Step 5: Replace Components as Needed If sensor resistance is out of specification or wiring shows damage, replace the DEF temperature sensor and repair harness sections as needed. Clear codes with diagnostic software and perform a test cycle to verify the repair.

Disclaimer: This guide provides general troubleshooting information. Always consult the official XCMG service manual for your specific machine serial number and seek professional assistance from certified heavy equipment technicians for complex repairs or if you're unsure about any diagnostic procedures.