Kobelco SK200-8S Fault Code P0335: Technical Guide

What is Kobelco SK200-8S Fault Code P0335?

Fault Code P0335 indicates a Crankshaft Position Sensor "A" Circuit malfunction in the Kobelco SK200-8S excavator's engine control system. This diagnostic trouble code (DTC) triggers when the Engine Control Module (ECM) detects an irregular, missing, or erratic signal from the crankshaft position sensor (CKP sensor) during engine operation.

The crankshaft position sensor is critical for the Kobelco SK200-8S's Hino J05E engine, as it monitors crankshaft speed and position to precisely control fuel injection timing, ignition timing (if applicable), and overall engine synchronization. When this sensor fails or its circuit is compromised, the ECM cannot accurately determine piston position, leading to performance degradation or complete engine shutdown. For used excavators operating in demanding environments, this sensor and its wiring are particularly vulnerable to vibration damage, contamination, and connector corrosion.

Common Symptoms

When P0335 is active on your SK200-8S, you may experience:

• Engine cranks but fails to start or starts with extreme difficulty
• Sudden engine stalling during operation, especially under load
• Rough idle, misfiring, or erratic engine performance with noticeable power loss
• Check Engine Light (CEL) or malfunction indicator lamp illuminated on the instrument panel
• Engine speed fluctuations or incorrect RPM readings on the monitor display

Potential Causes

Several factors commonly trigger P0335 in used Kobelco SK200-8S excavators:

• Failed or damaged crankshaft position sensor due to heat exposure, oil contamination, or internal component wear
• Damaged sensor wiring harness from vibration-induced chafing, particularly near the flywheel housing or engine block mounting points
• Corroded or loose electrical connectors at the sensor or ECM interface, especially in machines exposed to moisture or debris
• Worn or damaged reluctor ring (tone wheel) on the crankshaft with missing or damaged teeth
• ECM internal faults or software corruption (less common but possible in older units)
• Improper air gap between sensor tip and reluctor ring due to incorrect installation or sensor mounting bracket damage

How to Troubleshoot and Fix Code P0335

Step 1: Visual Inspection Begin by locating the crankshaft position sensor near the flywheel housing on the engine's lower section. Inspect the sensor mounting, checking for physical damage, excessive oil leakage, or metal debris accumulation on the sensor tip. Examine the wiring harness from sensor to ECM for visible damage, especially where it routes near moving components or sharp edges—a common wear point in used excavators.

Step 2: Electrical Testing Disconnect the sensor connector and use a digital multimeter to check sensor resistance. Typical CKP sensor resistance ranges from 500-1500 ohms (consult your service manual for exact specifications). Test the signal wire continuity from sensor to ECM connector and check for short circuits to ground. Inspect connector pins for corrosion, bent terminals, or moisture intrusion—clean with electrical contact cleaner if necessary.

Step 3: Signal Testing and Component Replacement Using Kobelco diagnostic software or a compatible scan tool, monitor the CKP sensor live data while cranking the engine. The sensor should produce a consistent AC voltage signal (typically 0.3-2.0V AC). If signal is absent or erratic, check the air gap between sensor and reluctor ring (usually 0.5-1.2mm). Inspect the reluctor ring for damaged teeth using a borescope if accessible. Replace the sensor if testing confirms failure, ensuring proper torque specifications (typically 10-12 Nm) and correct air gap during installation.

For used excavators, always verify that replacement sensors meet OEM specifications and thoroughly inspect all related components for age-related deterioration before finalizing repairs.

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Disclaimer: This guide provides general diagnostic information for P0335 on Kobelco SK200-8S excavators. Always consult the manufacturer's service manual and consider professional diagnostic assistance for complex electrical issues or if you lack appropriate testing equipment.