What is Liebherr General Fault Code E063?

Liebherr Fault Code E063 indicates a malfunction in the Engine Speed Sensor (ESS) circuit or an implausible engine speed signal being received by the Engine Control Module (ECM). This code triggers when the ECM detects inconsistent or missing data from the crankshaft position sensor or related wiring, preventing accurate monitoring of engine RPM.

This fault is critical for Liebherr excavators because the engine speed sensor directly affects fuel injection timing, governor control, and overall engine performance. When the ECM cannot reliably determine engine speed, it may initiate derate modes or prevent the machine from operating at full capacity to protect internal components. For used excavators, this code often points to sensor degradation, wiring harness damage from vibration, or connector corrosion—common issues in machines with high operating hours.

Common Symptoms

When Code E063 is active, operators typically experience:

• Engine warning light illuminated on the instrument cluster, often accompanied by a check engine indicator
• Erratic engine RPM readings on the dashboard, showing fluctuating or frozen speed displays
• Loss of power or engine derating, with the machine limiting maximum RPM to protect the engine
• Rough idling or stalling, particularly during startup or when transitioning between idle and working speeds
• Difficulty starting the engine, as the ECM cannot properly control fuel delivery without accurate speed data

Potential Causes

The most common technical reasons for E063 appearing on Liebherr excavators include:

• Failed or failing crankshaft position sensor due to heat exposure, internal component breakdown, or magnetic sensor contamination
• Damaged wiring harness near the sensor mounting location, often caused by rubbing against the engine block or flywheel housing
• Corroded or loose electrical connectors at the sensor or ECM—especially common in used machines exposed to moisture or hydraulic fluid leaks
• Worn flywheel ring gear teeth creating irregular magnetic signals that confuse the sensor
• ECM internal faults or corrupted software, though less common than sensor-circuit issues
• Improper sensor air gap, particularly after engine work or sensor replacement on older equipment

How to Troubleshoot and Fix Code E063

Step 1: Visual Inspection Begin by locating the engine speed sensor (typically mounted near the flywheel housing or crankshaft pulley). Inspect the sensor body for physical damage, oil contamination, or metal debris accumulation. Check the wiring harness from the sensor to the ECM for abrasion, cuts, or areas where the harness contacts moving parts—a frequent failure point in used excavators.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor connector and measure resistance across the sensor terminals. Liebherr sensors typically read between 800-1200 ohms (consult your specific model's service manual). Next, check for continuity in the wiring from the sensor connector to the ECM pins, and verify there's no short to ground. Measure the supply voltage at the connector (usually 5-12V depending on sensor type).

Step 3: Signal and Air Gap Verification Reconnect the sensor and use Liebherr diagnostic software (LiDat or equivalent) to monitor the live engine speed signal during cranking. The signal should show consistent pulses. Physically verify the sensor air gap using feeler gauges—correct gap is typically 0.5-1.5mm. On used machines, check the flywheel teeth for wear or damage that could cause signal irregularities.

Step 4: Component Replacement and Calibration If testing confirms sensor failure, replace with a genuine Liebherr or OEM-equivalent sensor and torque to specification. After replacement, clear the fault code and perform a sensor relearn procedure if required by your model. For persistent codes after sensor replacement, inspect the ECM ground connections and consider ECM diagnostics or replacement.

---

Disclaimer: This guide provides general troubleshooting information for Liebherr E063 fault codes. Always consult your machine's official service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs may cause additional damage or safety hazards.