Sany Excavator Fault Code P0335: Complete Diagnostic Guide

What is Sany General Fault Code P0335?

Fault Code P0335 indicates a Crankshaft Position Sensor "A" Circuit Malfunction. This diagnostic trouble code (DTC) means the Engine Control Module (ECM) has detected an irregular, absent, or intermittent signal from the crankshaft position sensor (CKP sensor).

The crankshaft position sensor is critical for Sany excavators because it monitors engine speed and crankshaft position, sending real-time data to the ECM. Without this signal, the ECM cannot properly control fuel injection timing, ignition timing, or detect engine misfires. This sensor is essential for diesel engine performance, startup reliability, and emissions control in Sany machinery.

Common Symptoms

When Code P0335 is active on your Sany excavator, you may experience:

• Hard starting or complete no-start condition – the engine cranks but fails to fire
• Check Engine Light (MIL) illuminated on the dashboard
• Rough idling or engine stalling during operation or at low RPM
• Engine performance derate – reduced power output and throttle response
• Intermittent engine cutouts especially when the machine is warm or under vibration

Potential Causes

The most common technical reasons for P0335 on used Sany excavators include:

• Damaged or contaminated crankshaft position sensor – oil leaks, metal shavings, or debris buildup on the sensor face
• Broken or frayed wiring harness – particularly at flex points near the engine block where vibration causes wire chafing
• Corroded or loose electrical connectors – moisture intrusion in the CKP sensor connector pins
• Faulty reluctor ring (tone wheel) – damaged or missing teeth on the crankshaft reluctor wheel
• ECM internal failure – less common but possible in high-hour used machines
• Incorrect sensor air gap – improper installation or mounting bracket damage

How to Troubleshoot and Fix Code P0335

Step 1: Visual Inspection Locate the crankshaft position sensor (typically mounted on the engine block near the crankshaft pulley or flywheel housing). Inspect the sensor for physical damage, oil contamination, or metal debris. On used excavators, carefully examine the wiring harness for abrasion points, especially where it contacts the engine block or frame rails.

Step 2: Electrical Testing Disconnect the sensor connector and inspect for corrosion, bent pins, or moisture. Using a digital multimeter, measure the sensor resistance – typical values range from 200-1000 ohms (consult your Sany service manual for exact specifications). Test the signal wire voltage with the key on, engine off – you should see battery voltage.

Step 3: Signal Testing Reconnect the sensor and use Sany diagnostic software or a compatible scan tool to monitor the CKP sensor signal while cranking. The signal should show consistent AC voltage pulses. No signal or erratic readings indicate sensor failure.

Step 4: Physical Inspection Check the sensor air gap using feeler gauges (typically 0.020-0.040 inches). Inspect the reluctor ring for broken teeth or damage by rotating the crankshaft manually.

Step 5: Repair or Replace Clean the sensor face and connector. Replace damaged wiring harnesses with OEM-grade components. If the sensor tests faulty, install a genuine Sany replacement. For used machines, always apply dielectric grease to connectors to prevent future corrosion.

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Disclaimer: This guide provides general troubleshooting information. Always consult your Sany service manual and consider professional diagnostic assistance for complex electrical issues or if you lack proper diagnostic equipment.