What is John Deere E240LC Fault Code 000174.04?

Fault Code 000174.04 indicates a Current Below Normal or Open Circuit condition in the Swing Motor Brake Solenoid circuit. This diagnostic trouble code (DTC) is generated when the Engine Control Module (ECM) or Machine Controller detects insufficient current flow through the swing brake solenoid valve, suggesting an electrical open circuit, damaged wiring, or failed solenoid component.

The swing motor brake system is critical for safe excavator operation, controlling the deceleration and holding function of the upper structure during rotation. When this code activates, the machine's safety protocols may engage to prevent uncontrolled swing motion, directly impacting productivity and operator safety. On used John Deere E240LC excavators, this fault often stems from age-related electrical degradation rather than component failure alone.

Common Symptoms

• Swing function becomes sluggish or unresponsive when attempting to rotate the upper structure
• Swing brake warning icon illuminated on the instrument cluster or monitor display
• Audible alarm accompanied by reduced swing performance or complete swing lockout
• Machine derate mode may activate, limiting other hydraulic functions as a safety precaution
• Intermittent swing operation, where the brake releases inconsistently during rotation attempts

Potential Causes

The most common technical causes for Code 000174.04 on used E240LC excavators include:

• Damaged or corroded wiring harness at known rub points near the swing bearing raceway where cables flex during rotation
• Failed swing brake solenoid coil due to internal short circuit or coil winding deterioration
• Corroded or loose electrical connectors at the solenoid valve or main harness junction points
• Broken or frayed wires inside the protective loom, especially in high-flex zones near the center joint
• ECM or controller internal faults (less common, but possible in high-hour used machines)
• Blown fuse or faulty relay in the swing brake circuit power supply

How to Troubleshoot and Fix Code 000174.04

Step 1: Visual Inspection Begin by inspecting the swing brake solenoid valve located on the swing motor assembly. Check the electrical connector for corrosion, moisture intrusion, or bent pins. On used excavators, pay particular attention to the wiring harness routing through the center joint—look for abraded insulation, exposed conductors, or previous repair attempts with electrical tape.

Step 2: Electrical Testing Using a digital multimeter (DMM), disconnect the solenoid connector and measure coil resistance across the solenoid terminals. Typical resistance values range from 10-30 ohms (consult John Deere service manual for exact specifications). An open circuit (infinite resistance) confirms solenoid failure. Next, check for supply voltage at the harness connector with ignition on—should read approximately 12-24 VDC depending on system design.

Step 3: Harness Continuity Check Trace the harness circuit from the solenoid back to the ECM connector, checking for continuity using your multimeter. Focus on high-wear areas where the harness passes through the swing bearing area. Repair or replace any sections showing resistance above 5 ohms or intermittent readings.

Step 4: Component Replacement If the solenoid tests faulty, replace it with a genuine John Deere part to ensure proper current draw specifications. After replacement, clear the fault code using John Deere Service Advisor diagnostic software or an compatible OBD scan tool, then cycle the swing function multiple times to verify proper operation.

Step 5: Post-Repair Verification Operate the excavator through full swing cycles in both directions while monitoring for code recurrence. Check that the swing brake engages and releases smoothly without hesitation.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official John Deere service manual for your specific machine serial number and software version. If you're unfamiliar with electrical diagnostics or high-voltage systems, seek assistance from a certified John Deere technician to avoid injury or further equipment damage.