What is XCMG XE750D Fault Code E1585(2) SPN7105 FMI31?

Fault Code E1585(2) with SPN7105 FMI31 indicates a data condition exists where the Engine Control Module (ECM) has detected abnormal data or a signal that is outside normal operating parameters for a specific engine system component. This is a J1939 diagnostic trouble code where SPN 7105 relates to engine system data communication, and FMI 31 specifically flags a "Condition Exists" warning rather than a hard electrical failure.

On the XCMG XE750D excavator, this code typically involves communication issues between the ECM and critical engine sensors or actuators within the Cummins or Isuzu powerplant (depending on your machine's configuration). This fault is critical because it can trigger engine derate modes, limiting machine performance and productivity. In used excavators, this code often surfaces due to degraded wiring harnesses, corroded connectors, or failing sensors that have accumulated wear over thousands of operating hours.

Common Symptoms

• Amber warning light illuminated on the instrument cluster with reduced engine power
• Engine derate mode activated, limiting maximum RPM to 1500-1800 range
• Intermittent loss of throttle response or hesitation during load cycles
• ECM data errors displayed on diagnostic screens showing implausible sensor readings
• Machine may enter limp mode during high-demand hydraulic operations

Potential Causes

The most common technical causes for E1585(2) SPN7105 FMI31 on used XCMG XE750D excavators include:

• Corroded or loose connector pins at the ECM harness interface (common failure point after 5,000+ hours)
• Damaged CAN bus wiring along the engine valley or near the turbocharger where heat degradation occurs
• Failing crankshaft position sensor or camshaft position sensor sending intermittent signals
• ECM software corruption or outdated firmware requiring reflashing
• Voltage supply issues from the main power harness (check for voltage drops below 22V on 24V systems)
• Aftermarket modifications or spliced wiring creating signal interference

How to Troubleshoot and Fix Code E1585(2) SPN7105 FMI31

Step 1: Connect Diagnostic Software Use XCMG-approved diagnostic software or a compatible J1939 scanner (Nexiq USB-Link 2 or similar). Capture active and stored fault codes. Check freeze frame data to identify which sensor or system triggered the condition.

Step 2: Inspect Wiring Harnesses and Connectors On used excavators, physically inspect the engine harness from ECM to all sensors. Look for:

• Rubbed or chafed wiring at frame contact points
• Green corrosion on connector pins (especially at ECM 120-pin connector)
• Cracked or brittle insulation from heat exposure Clean all connections with electrical contact cleaner and apply dielectric grease.

Step 3: Test Sensor Signals and Power Supply Using a digital multimeter, verify:

• Battery voltage at ECM (should be 24V ±2V with key on)
• Ground continuity at ECM mounting points (less than 0.5 ohms resistance)
• Individual sensor signals per manufacturer specifications

Step 4: Clear Codes and Road Test After repairs, clear fault codes and operate the machine under load. Monitor for code reoccurrence. If the fault returns immediately, suspect ECM internal failure or corrupted software requiring professional reflashing.

Step 5: Check for Technical Service Bulletins Contact an XCMG dealer to verify if TSBs exist for your serial number range addressing CAN bus communication issues.

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Disclaimer: This guide provides general troubleshooting information. Complex electrical diagnostics should be performed by certified technicians with proper training and equipment. Always consult the official XCMG service manual for your specific machine serial number before performing repairs.