What is Kato General Fault Code P1335?

Fault Code P1335 indicates a Crankshaft Position Sensor "A" Circuit Malfunction or correlation error between the crankshaft position sensor and camshaft position sensor. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects an irregular signal pattern from the crankshaft position (CKP) sensor or identifies timing discrepancies that don't align with expected engine synchronization parameters.

In Kato excavators, the CKP sensor is critical for monitoring engine speed and piston position, directly affecting fuel injection timing and ignition sequencing. When this sensor fails or provides erratic data, the ECM cannot accurately determine the engine's rotational position, leading to poor performance, rough idling, or complete engine shutdown. For used excavators, this code often appears due to sensor degradation, wiring harness damage from years of vibration, or connector corrosion common in machines with extended operational hours.

Common Symptoms

When Code P1335 is active, operators typically experience:

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

Potential Causes

The most common technical reasons for P1335 on used Kato excavators include:

• Faulty crankshaft position sensor due to internal component wear or heat damage
• Damaged or corroded wiring harness at known rub points near the engine block or flex points
• Loose or corroded electrical connectors at the CKP sensor plug
• Timing belt/chain wear causing actual timing misalignment between crankshaft and camshaft
• ECM software issues or internal ECM faults (less common)
• Reluctor ring damage (tone wheel) on the crankshaft with missing or damaged teeth
• Magnetic debris accumulation on the sensor tip affecting signal quality

How to Troubleshoot and Fix Code P1335

Step 1: Visual Inspection Begin with a thorough inspection of the CKP sensor and its wiring harness. Check for physical damage, oil contamination, or metallic debris on the sensor face. Inspect the connector terminals for corrosion, bent pins, or moisture intrusion—common issues in used excavators. Examine harness routing for wear points where cables contact the frame or engine components.

Step 2: Electrical Testing Using a digital multimeter, measure the CKP sensor resistance (typically 200-900 ohms, but consult Kato specifications). Test the signal wire voltage with the ignition on (should show battery voltage). Check for continuity between the sensor and ECM, and verify proper ground connection integrity. For used machines, corrosion in ground points is frequently overlooked.

Step 3: Signal Analysis and Component Replacement Connect Kato diagnostic software or a compatible scan tool to monitor live CKP sensor data during cranking. Look for irregular signal patterns or dropouts. If electrical tests pass but symptoms persist, inspect the reluctor ring for damage. Replace the CKP sensor with OEM or quality aftermarket parts, ensuring proper air gap specification (typically 0.5-1.5mm). Clear codes and perform a test run under load.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Kato service manual for your specific model and consider professional diagnostic assistance for complex electrical issues or internal engine timing concerns.