Kobelco SK480LC-8 Fault Code P0335: Complete Diagnostic Guide

What is Kobelco SK480LC-8 Fault Code P0335?

Fault Code P0335 indicates a Crankshaft Position Sensor "A" Circuit malfunction in the Kobelco SK480LC-8 excavator's engine control system. This code is triggered when the Engine Control Module (ECM) fails to receive a proper signal from the Crankshaft Position Sensor (CKP), which monitors the crankshaft's rotational speed and position.

The CKP sensor is critical for precise fuel injection timing and ignition synchronization in the SK480LC-8's diesel engine. Without accurate crankshaft position data, the ECM cannot optimize combustion efficiency, leading to reduced performance, increased emissions, and potential engine damage. This code commonly appears in used excavators due to sensor degradation, wiring harness wear from vibration, or connector corrosion from environmental exposure.

Common Symptoms

When P0335 is active on your Kobelco SK480LC-8, you may experience:

• Hard starting or no-start condition, especially when the engine is cold
• Engine stalling during operation or at idle
• Check Engine Light (CEL) illuminated on the instrument panel
• Rough idle with noticeable vibration or inconsistent RPM
• Loss of power or hesitation during acceleration and digging operations

Potential Causes

Several factors can trigger P0335 in used SK480LC-8 excavators:

• Faulty Crankshaft Position Sensor due to heat exposure or internal component failure
• Damaged or corroded wiring harness between the CKP sensor and ECM, particularly at flex points near the engine mounts
• Loose or corroded electrical connectors at the sensor or ECM terminals
• Broken reluctor ring (tone wheel) on the crankshaft causing irregular sensor readings
• ECM internal circuit failure affecting the CKP sensor input channel
• Insufficient sensor air gap between the sensor tip and reluctor ring teeth

How to Troubleshoot and Fix Code P0335

Step 1: Visual Inspection Locate the CKP sensor on the engine block (typically near the crankshaft pulley or flywheel housing). Inspect the wiring harness for abrasion, cuts, or melting—common in used machines where harnesses rub against engine components. Check all connectors for corrosion, moisture, or bent pins.

Step 2: Electrical Testing Using a digital multimeter, measure the sensor resistance (typically 200-900 ohms for most CKP sensors; consult Kobelco specifications). Test the signal wire voltage while cranking the engine—you should see an AC voltage signal (usually 0.3-1.0V AC). Check harness continuity from sensor to ECM and verify there's no short to ground.

Step 3: Sensor Air Gap Check Measure the air gap between the sensor tip and reluctor ring teeth using feeler gauges (specification typically 0.5-1.2mm). For used excavators, inspect the reluctor ring for missing teeth, damage, or excessive metal debris buildup that could interfere with readings.

Step 4: Component Replacement If testing confirms sensor failure, replace the CKP sensor with a genuine Kobelco part or high-quality OEM equivalent. When reinstalling, apply anti-seize compound to the threads and ensure proper air gap. Clear the fault code using diagnostic software and perform a test run under load.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Kobelco service manual for your specific machine serial number and seek professional assistance if you're unfamiliar with electrical diagnostics or engine repair procedures.