What is Hitachi ZH200-5A Fault Code P0335?

Fault Code P0335 indicates a Crankshaft Position Sensor "A" Circuit Malfunction in the Hitachi ZH200-5A excavator's engine control system. This diagnostic trouble code (DTC) means the Engine Control Module (ECM) is not receiving a proper signal from the crankshaft position (CKP) sensor, which monitors engine speed and crankshaft angle.

The CKP sensor is critical for the ZH200-5A's Isuzu diesel engine because it provides real-time data that the ECM uses to control fuel injection timing, ignition timing, and overall engine synchronization. Without accurate crankshaft position data, the engine cannot operate efficiently or may fail to start altogether. In used excavators, this fault often stems from sensor wear, damaged wiring harnesses exposed to engine heat and vibration, or connector corrosion common in older machines operating in harsh environments.

Common Symptoms

When P0335 is active on your Hitachi ZH200-5A, you may experience:

• Engine cranks but fails to start or experiences prolonged cranking before firing
• Check Engine Light (CEL) or malfunction indicator lamp illuminated on the instrument cluster
• Rough idle, misfiring, or stalling during operation, especially under load
• Loss of power or engine running in derate/limp mode with reduced RPM capability
• Intermittent starting issues that worsen as the machine warms up or cools down

Potential Causes

Several factors can trigger P0335 in used ZH200-5A excavators:

• Failed crankshaft position sensor due to heat exposure, age, or internal component breakdown
• Damaged sensor wiring harness from rubbing against engine components, common near the flywheel housing
• Corroded or loose electrical connectors at the CKP sensor or ECM, especially in machines exposed to moisture
• Worn flywheel teeth or reluctor ring damage preventing proper magnetic signal generation
• ECM internal fault or software corruption (less common but possible in older units)
• Incorrect air gap between sensor and reluctor wheel due to mounting bracket wear or previous improper installation

How to Troubleshoot and Fix Code P0335

Step 1: Visual Inspection Locate the crankshaft position sensor near the flywheel/flexplate area on the engine block. Inspect the sensor connector for corrosion, oil contamination, or bent pins. Check the wiring harness for wear, particularly where it routes near hot engine surfaces or moving components—a common failure point in used excavators.

Step 2: Electrical Testing Using a digital multimeter, test sensor resistance (typically 200-900 ohms for most CKP sensors, but verify with Hitachi service manual specifications). Check for continuity in the wiring from sensor to ECM. Test for proper voltage supply (usually 5V or 12V reference voltage) at the sensor connector with ignition on, engine off.

Step 3: Signal Testing and Air Gap Use an oscilloscope or Hitachi Dr.EX diagnostic software to verify the sensor produces an AC voltage signal when cranking. Measure the air gap between sensor tip and reluctor wheel (typically 0.5-1.2mm); adjust if necessary. Inspect the flywheel reluctor ring for damaged or missing teeth.

Step 4: Component Replacement If testing confirms sensor failure, replace with a genuine Hitachi or OEM-equivalent CKP sensor. For used excavators, always replace the connector pigtail simultaneously if any corrosion is present. Clear codes with diagnostic software and perform a cranking test.

Disclaimer: This guide provides general troubleshooting steps. Always consult the official Hitachi ZH200-5A service manual and consider professional diagnostic assistance for complex electrical issues or if you lack proper diagnostic tools.