What is XCMG B3.9-5.9-C8.3 CM2150 Fault Code 654-5?

Fault Code 654-5 indicates an Injector Cylinder #5 - Current Below Normal or Open Circuit condition. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects that the electrical current flowing through the fuel injector solenoid for cylinder #5 is below the manufacturer's specified threshold or has lost continuity entirely.

In the Cummins CM2150 engine platform used in XCMG excavators, precise fuel delivery is critical for maintaining performance, emissions compliance, and fuel efficiency. The ECM continuously monitors injector circuit current to ensure each cylinder receives the correct fuel quantity at the proper timing. When current falls below normal parameters (typically during injector actuation), the ECM logs this fault and may implement power derate to protect the engine from damage caused by improper combustion or cylinder misfiring.

Common Symptoms

• Check Engine Light or Malfunction Indicator Lamp (MIL) illuminated on the instrument cluster
• Noticeable rough idle or engine vibration due to cylinder #5 not firing properly
• Loss of power or reduced hydraulic performance, especially under heavy load conditions
• Engine derate mode activated, limiting maximum RPM to 1500 or lower
• Increased black or white exhaust smoke caused by incomplete combustion in the affected cylinder

Potential Causes

The most common technical causes for Code 654-5 in used XCMG excavators include:

• Faulty injector solenoid on cylinder #5 due to internal coil failure or mechanical wear
• Open circuit or broken wiring in the injector harness, particularly at known rub points near the valve cover or engine block
• Corroded or loose electrical connectors at the injector or ECM connection points—extremely common in machines with high operating hours
• Damaged ECM injector driver circuit caused by voltage spikes or previous electrical faults
• Intermittent connection due to harness chafing against engine components during vibration

How to Troubleshoot and Fix Code 654-5

Step 1: Visual Inspection Perform a thorough inspection of the injector wiring harness for cylinder #5. Check for visible damage, fraying, or wear points where the harness contacts the engine block or valve cover. Inspect the injector connector and ECM connector for corrosion, bent pins, or moisture intrusion—critical on used excavators operating in harsh environments.

Step 2: Electrical Testing Using a digital multimeter, measure the resistance of the cylinder #5 injector solenoid. Typical resistance values range from 0.3 to 0.9 ohms (consult your service manual for exact specifications). Test for continuity from the injector connector through the harness to the ECM connector. Any reading of infinite resistance indicates an open circuit requiring harness repair or replacement.

Step 3: Injector and ECM Diagnosis If wiring checks pass, use Cummins INSITE diagnostic software or compatible scan tool to perform an injector solenoid test. This active test energizes the injector while monitoring current draw. Replace the fuel injector if it fails to meet current specifications. If multiple injectors show issues, inspect the ECM injector driver circuits for damage—common in machines with electrical system abuse or improper jump-starting procedures.

For used excavators, always check connector seals and apply dielectric grease to prevent future corrosion before reassembly.

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Disclaimer: This guide provides general troubleshooting information. Always consult the manufacturer's service manual and consider professional diagnostic services for complex electrical or fuel system repairs.