What is Hyundai R335LC-9T Fault Code 2345?

Fault Code 2345 on the Hyundai R335LC-9T excavator indicates a malfunction in the main control valve solenoid circuit, specifically related to the swing motor control system. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects an abnormal electrical signal or voltage irregularity in the proportional solenoid valve that regulates hydraulic flow to the swing function.

This code is critical for the R335LC-9T because the swing motor control solenoid directly affects upper structure rotation performance. When this circuit malfunctions, the excavator's ability to execute precise swing operations becomes compromised, reducing productivity and potentially creating safety hazards on job sites. The Hyundai D6CB diesel engine and hydraulic system rely on precise electronic signals to maintain optimal performance, making this electrical fault particularly important to address promptly.

Common Symptoms

• Erratic or jerky swing movement during upper structure rotation, with inconsistent speed control
• Complete loss of swing function while other hydraulic operations remain normal
• Warning lamp illumination on the instrument cluster, often accompanied by audible alarms
• Reduced swing speed or inability to achieve full rotational velocity under load
• Intermittent swing operation that works occasionally but fails unpredictably during operation

Potential Causes

The most common technical causes for Code 2345 on used R335LC-9T excavators include:

• Damaged wiring harness between the main controller and swing control valve, particularly at known rub points near the swing bearing where cable flexing occurs during rotation
• Failed proportional solenoid coil within the main control valve assembly due to age-related deterioration or moisture intrusion
• Corroded electrical connectors at the swing solenoid valve connection point, common in machines operating in wet or coastal environments
• Internal short circuit or open circuit in the solenoid valve wiring caused by vibration fatigue
• ECM internal fault or corrupted software calibration affecting solenoid driver output
• Voltage supply issues from the machine's electrical system providing inconsistent power to the control circuit

How to Troubleshoot and Fix Code 2345

Step 1: Visual Inspection and Connector Examination Begin by accessing the main control valve located on the right side of the uppercarriage. Disconnect the electrical connector to the swing control solenoid and inspect for corrosion, bent pins, or moisture contamination. On used excavators, check the wiring harness routing for abrasion points where cables contact the swing bearing housing—a common failure point on machines with over 5,000 hours.

Step 2: Electrical Testing with Diagnostic Tools Using a digital multimeter, measure the resistance of the solenoid coil. Specifications for the R335LC-9T swing solenoid typically range between 8-12 ohms at room temperature. Next, check for voltage supply at the connector with the ignition on—you should see approximately 12-14 volts. Utilize Hyundai's Hi-MATE diagnostic software to perform active solenoid tests and monitor real-time circuit performance.

Step 3: Harness Continuity and ECM Output Verification Test wire continuity from the solenoid connector back to the ECM pins specified in the service manual. Pay special attention to the ground circuit integrity. For used machines, inspect the entire harness length for internal wire breaks caused by repeated flexing. If all wiring tests pass, verify the ECM driver output using an oscilloscope to check pulse-width modulation signals—abnormal waveforms indicate ECM replacement may be necessary.

Step 4: Component Replacement and System Verification Replace faulty components starting with the most common failures: solenoid valve, then harness sections, and finally the ECM if diagnostics confirm controller failure. After repairs, clear the fault code using diagnostic software and perform operational testing under load conditions to verify proper swing function restoration.

Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Hyundai service manual for your specific machine serial number and seek professional assistance for complex electrical diagnostics or hydraulic system repairs.