What is Liebherr General Fault Code E116?

Fault Code E116 on Liebherr excavators indicates a malfunction in the Engine Coolant Temperature (ECT) Sensor circuit or an out-of-range temperature reading. This code is triggered when the Electronic Control Module (ECM) detects an implausible voltage signal from the coolant temperature sensor, typically caused by an open circuit, short circuit, or sensor failure. The ECT sensor is critical for proper engine management, as it directly influences fuel injection timing, idle speed control, and engine protection protocols. When this sensor fails, the ECM cannot accurately monitor engine thermal conditions, potentially leading to overheating, inefficient combustion, or unintended engine shutdowns on Liebherr machinery.

In used excavators, this fault becomes particularly concerning because prolonged operation without accurate temperature monitoring can cause severe engine damage, including warped cylinder heads or cracked engine blocks. The ECM relies on this sensor data to activate cooling fans and adjust performance parameters under load.

Common Symptoms

• Engine warning light or check engine light illuminated on the instrument cluster
• Engine running in limp mode or derate mode, with reduced power output and hydraulic response
• Cooling fan running continuously at high speed, even when engine is cold
• Difficulty starting the engine, especially in cold weather conditions
• Erratic idle speed fluctuations or rough running during warm-up
• Temperature gauge reading incorrectly (stuck at cold or maximum hot position)

Potential Causes

The most common technical reasons for E116 appearing on Liebherr excavators include:

• Faulty ECT sensor due to internal element degradation or contamination from coolant additives (common in machines with 5,000+ operating hours)
• Damaged wiring harness or corroded connectors at the sensor plug, particularly where the harness passes near the engine block or exhaust manifold (known rub point on older Liebherr models)
• Open or short circuit in the sensor signal wire between the ECT sensor and the ECM
• Corroded or loose ground connections affecting sensor voltage reference
• Low coolant level causing air pockets around the sensor, leading to false readings
• ECM internal fault (rare, but possible in high-hour used machines with electrical system exposure to moisture)

How to Troubleshoot and Fix Code E116

Step 1: Visual Inspection Begin by inspecting the ECT sensor location on the engine block (typically near the thermostat housing). Check for coolant leaks, corrosion on the connector pins, and physical damage to the sensor body. On used excavators, examine the wiring harness routing for signs of chafing, melting, or previous repairs with electrical tape—these are common failure points.

Step 2: Electrical Testing Disconnect the ECT sensor connector and use a digital multimeter to measure sensor resistance. At room temperature (20°C/68°F), resistance should typically read between 2,000-3,000 ohms (consult Liebherr service manual for exact specifications). Check for continuity between the sensor terminals and ground; any continuity indicates a shorted sensor requiring replacement.

Step 3: Circuit Voltage Check With the ignition on and sensor disconnected, measure voltage at the ECM-side connector. You should see approximately 5 volts reference voltage from the ECM. If voltage is absent, inspect the harness between the sensor and ECM for breaks or shorts to ground.

Step 4: Coolant System Verification Verify proper coolant level and check for air pockets in the cooling system. Bleed the system according to Liebherr procedures, as air trapped near the sensor will cause erratic readings even with a functional sensor.

Step 5: Connector Cleaning and Repair Clean all connector pins with electrical contact cleaner and apply dielectric grease to prevent future corrosion—critical for used machines operating in harsh environments. Repair any damaged harness sections with proper gauge wire and heat-shrink connections.

Step 6: Component Replacement If testing confirms sensor failure, replace with a genuine Liebherr ECT sensor or high-quality OEM equivalent. After replacement, clear the fault code using Liebherr LiDat diagnostic software and perform a test run to verify proper temperature readings.

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Disclaimer: This guide provides general troubleshooting information for Liebherr excavators. Always consult the official Liebherr service manual for your specific model and serial number. If you're unfamiliar with electrical diagnostics or lack proper tools, consult a certified Liebherr technician to prevent further damage to used equipment.