What is Hitachi ZX350LCK-5G Fault Code 11006-2?

Fault Code 11006-2 on the Hitachi ZX350LCK-5G excavator indicates an Engine Speed Sensor (Crankshaft Position Sensor) signal malfunction with an intermittent or erratic signal pattern. This code is triggered when the Engine Control Module (ECM) detects inconsistent voltage signals from the crankshaft position sensor circuit, preventing accurate monitoring of engine RPM and timing.

This fault is critical for the ZX350LCK-5G's Isuzu engine performance because the crankshaft position sensor provides essential data for fuel injection timing, ignition control, and overall engine synchronization. When this sensor fails or sends corrupted signals, the ECM cannot properly manage combustion cycles, leading to reduced power output and potential engine protection modes. On used excavators, this code frequently appears due to sensor degradation, wiring harness damage from vibration, or connector corrosion from environmental exposure.

Common Symptoms

• Engine warning light illuminated on the instrument cluster with possible derate mode activation
• Rough idling or inconsistent engine RPM, particularly noticeable at low speeds
• Hard starting or extended cranking time, especially during cold starts
• Sudden engine stalling during operation or inability to restart after shutdown
• Loss of power under load with the engine failing to reach maximum RPM

Potential Causes

The most common technical causes for Code 11006-2 on used ZX350LCK-5G excavators include:

• Worn or damaged crankshaft position sensor due to heat exposure and age-related deterioration
• Corroded or loose electrical connectors at the sensor harness connection point near the flywheel housing
• Damaged wiring harness caused by vibration-induced chafing against engine components or frame rails
• Contaminated sensor face from oil leaks, metal debris, or excessive dirt accumulation affecting the magnetic field
• Faulty ECM or internal ECM circuit degradation (less common but possible on high-hour machines)
• Improper air gap between the sensor tip and crankshaft reluctor ring due to mounting bracket wear

How to Troubleshoot and Fix Code 11006-2

Step 1: Visual Inspection Begin by inspecting the crankshaft position sensor located on the lower engine block near the flywheel. Check for physical damage, oil contamination, or debris buildup on the sensor face. Examine the wiring harness from the sensor to the ECM for visible damage, particularly at known rub points against engine mounts and frame brackets common in used machines.

Step 2: Electrical Testing Using a digital multimeter, measure the sensor's resistance (typically 200-1000 ohms depending on specifications). Check for voltage output while cranking the engine—you should see an AC voltage signal fluctuating between 0.5-3.0 volts. Inspect all connector pins for corrosion, bent terminals, or moisture intrusion, which is especially common on excavators with high operating hours.

Step 3: Signal Verification and Repair Connect Hitachi diagnostic software (Dr.EX) to monitor real-time sensor signal quality and frequency. If the signal shows erratic patterns or dropouts, replace the crankshaft position sensor and ensure proper air gap (typically 0.5-1.5mm). For used excavators, always replace the connector pigtail if any corrosion is present, as intermittent connections cause recurring codes.

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