What is Hyundai HX220 NL EPFC Fault Code 2013?

Fault Code 2013 on the Hyundai HX220 NL EPFC indicates a malfunction in the engine coolant temperature sensor circuit, specifically a signal voltage that is out of the normal operating range or an intermittent connection issue. This code is generated when the Electronic Control Module (ECM) detects that the coolant temperature sensor is sending abnormal voltage readings—either too high (open circuit) or too low (short circuit)—preventing accurate engine temperature monitoring.

This fault is critical for the HX220 NL EPFC because the ECM relies on accurate coolant temperature data to manage fuel injection timing, engine warm-up cycles, and protection protocols. Without reliable temperature readings, the machine may enter derate mode to prevent engine damage, significantly reducing operational efficiency and potentially causing expensive downtime on job sites.

Common Symptoms

• Check Engine Light or warning indicator illuminated on the instrument cluster
• Engine running in cold start mode continuously, causing rough idle and increased fuel consumption
• Power derate or reduced hydraulic performance, especially under load
• Difficulty starting in cold weather conditions due to improper fuel delivery adjustments
• Erratic temperature gauge readings or gauge stuck at cold position

Potential Causes

The most common technical causes for Code 2013 on used HX220 NL excavators include:

• Faulty coolant temperature sensor due to internal element degradation from thermal cycling over thousands of operating hours
• Corroded or damaged wiring harness connectors at the sensor plug, particularly common in machines exposed to muddy or wet job sites
• Chafed wiring along the harness routing near the engine block where vibration causes insulation wear—a known issue on this model near the fuel filter mounting bracket
• Poor ground connection at the sensor circuit return path
• ECM internal fault (rare, but possible in high-hour used machines with moisture intrusion)
• Contaminated coolant causing sensor element coating and inaccurate readings

How to Troubleshoot and Fix Code 2013

Step 1: Visual Inspection Begin by locating the coolant temperature sensor on the engine block (typically near the thermostat housing on the HX220 NL). Inspect the wiring harness for obvious damage, chafing, or corrosion—pay special attention to areas where the harness contacts metal surfaces or passes near heat sources. On used excavators, check connector pins for green corrosion or bent terminals.

Step 2: Electrical Testing Disconnect the sensor connector and use a digital multimeter to check sensor resistance. At room temperature (68°F/20°C), resistance should typically read between 2,000-3,000 ohms (consult your service manual for exact specifications). Test the harness side for continuity to the ECM and check for proper ground integrity (should read less than 5 ohms resistance to chassis ground).

Step 3: Signal Voltage Verification With the key on and sensor disconnected, measure voltage at the harness connector. You should see approximately 5 volts reference voltage from the ECM. If voltage is absent or incorrect, trace the harness for breaks or check ECM power supply circuits.

Step 4: Component Replacement and Verification If the sensor tests faulty, replace it with an OEM or quality aftermarket unit and apply dielectric grease to connector terminals to prevent future corrosion—especially important in used equipment. Clear the fault code using Hyundai Hi-MATE diagnostic software or a compatible J1939 scan tool, then run the engine through temperature cycles to verify the repair.

For used excavators, always inspect harness routing and secure any loose sections with proper standoffs to prevent future chafing issues.

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Disclaimer: This guide provides general troubleshooting information. Always consult the Hyundai HX220 NL service manual and consider professional diagnostic assistance for complex electrical issues or if you're unfamiliar with high-voltage systems.