What is XCMG XE750D Fault Code 267-4 SPN4215 FMI4?

Fault Code 267-4 (SPN 4215, FMI 4) on the XCMG XE750D excavator indicates an Aftertreatment Fuel Pressure Actuator Circuit experiencing voltage below normal or shorted to ground. This code specifically relates to the diesel exhaust fluid (DEF) injection system's fuel pressure control circuit within the aftertreatment system.

SPN 4215 refers to the Aftertreatment Fuel Pressure Actuator, while FMI 4 designates a voltage below normal or short circuit to ground condition. This fault affects the selective catalytic reduction (SCR) system's ability to properly inject DEF into the exhaust stream, which is critical for meeting emissions standards and maintaining optimal engine performance. If left unaddressed, this code can trigger engine derate modes or prevent the machine from starting after shutdown on emissions-compliant XE750D models.

Common Symptoms

• Check Engine Light (CEL) or Malfunction Indicator Lamp (MIL) illuminated on the instrument cluster
• Engine derate or reduced power output after extended operation with active fault
• DEF system warning messages displayed on the monitor screen
• Excessive DEF consumption or no DEF consumption at all
• Difficulty starting after the machine has been shut down (particularly in newer emissions-compliant units)

Potential Causes

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

• Damaged or corroded wiring harness between the Engine Control Module (ECM) and the aftertreatment fuel pressure actuator (common wear point near exhaust components due to heat exposure)
• Failed aftertreatment fuel pressure actuator solenoid due to internal short circuit or coil degradation
• Corroded or loose connector pins at the actuator connection point (moisture intrusion is common in older machines)
• Chafed wiring where harness routes near sharp edges or moving components
• ECM internal fault or software calibration issue (less common)
• Poor ground connection at chassis ground points affecting circuit integrity

How to Troubleshoot and Fix Code 267-4 SPN4215 FMI4

Step 1: Visual Inspection of Wiring and Connections

Begin by locating the aftertreatment fuel pressure actuator near the SCR system (typically mounted on or near the exhaust aftertreatment canister). Inspect the wiring harness for obvious damage, burns, chafing, or corrosion. On used excavators, pay special attention to harness routing near hot exhaust components where insulation may have deteriorated. Check all connector pins for corrosion, bent pins, or moisture intrusion.

Step 2: Electrical Testing with Multimeter

Disconnect the actuator connector and perform resistance checks. Using a digital multimeter (DMM), measure the resistance across the actuator solenoid terminals. Typical specifications range from 3-8 ohms (consult XCMG service manual for exact values). Next, check for short to ground by measuring resistance between each actuator terminal and chassis ground—readings should show infinite resistance (open circuit). If resistance to ground is low (below 10k ohms), the actuator or wiring is shorted.

Step 3: Voltage Supply Verification

Reconnect the harness and back-probe the connector with the ignition on. Verify battery voltage (12-14V) is present on the supply wire when the ECM commands actuator activation. Use XCMG diagnostic software or a compatible scan tool to perform an actuator function test. If voltage is absent or below 10V, trace the circuit back toward the ECM checking for voltage drops indicating high resistance connections.

Step 4: Component Replacement and Harness Repair

If testing confirms actuator failure, replace the aftertreatment fuel pressure actuator with an OEM or quality aftermarket part. For wiring issues, repair damaged sections using proper gauge wire, heat shrink connectors, and ensure routing avoids heat sources. Apply dielectric grease to all connector pins before reassembly to prevent future corrosion—especially critical on used machines operating in humid or corrosive environments.

Step 5: Clear Codes and Verify Repair

After repairs, clear fault codes using diagnostic software and operate the machine under load for at least 30 minutes. Monitor the system to ensure the code does not return and DEF consumption returns to normal levels.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official XCMG service manual for your specific machine serial number and software version. If you're uncomfortable performing electrical diagnostics, consult a certified XCMG technician or qualified heavy equipment mechanic to prevent further damage or safety hazards.