What is Hitachi ZH200LC-5A Fault Code P0335?

Fault Code P0335 indicates a Crankshaft Position Sensor "A" Circuit malfunction in the Hitachi ZH200LC-5A excavator's engine control system. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) fails to receive a consistent or accurate signal from the Crankshaft Position (CKP) Sensor during engine operation or cranking.

The CKP sensor is a critical component that monitors the rotational speed and exact position of the crankshaft, sending this data to the ECM. The ECM uses this information to precisely control fuel injection timing and ignition timing (in applicable engines). On the ZH200LC-5A, which typically features an Isuzu diesel engine, this sensor is vital for proper engine starting, smooth idle, and optimal power delivery. When this code appears, the engine management system cannot accurately determine crankshaft position, leading to performance issues or complete shutdown.

Common Symptoms

When Code P0335 is active on your Hitachi ZH200LC-5A, you may experience:

• Hard starting or no-start condition – the engine cranks but fails to fire or takes excessive cranking time
• Engine Check Light or Malfunction Indicator Lamp (MIL) illuminated on the dashboard
• Rough idle or unexpected stalling during operation, especially at low RPMs
• Loss of engine power or hesitation during acceleration under load
• Engine misfires or irregular combustion patterns affecting hydraulic performance

Potential Causes

Several factors commonly trigger P0335 on used excavators, particularly those with higher operating hours:

• Failed or failing Crankshaft Position Sensor due to heat exposure, vibration, or internal component breakdown
• Damaged sensor wiring harness from abrasion against the engine block or frame – a known wear point on older ZH200LC-5A models
• Corroded or loose electrical connectors at the CKP sensor or ECM, especially in machines exposed to moisture or mud
• Broken or missing reluctor ring teeth on the crankshaft (rare but possible after major engine work)
• ECM internal faults or corrupted sensor signal processing circuits
• Incorrect air gap between the sensor and reluctor wheel due to improper installation or mounting bracket damage

How to Troubleshoot and Fix Code P0335

Step 1: Visual Inspection Begin by locating the CKP sensor (typically mounted near the crankshaft pulley or flywheel housing). Inspect the sensor itself and the wiring harness for obvious damage, oil contamination, or loose connections. On used excavators, carefully check for harness chafing where wires route near moving components or sharp edges.

Step 2: Electrical Testing Using a digital multimeter, test the sensor's resistance according to Hitachi/Isuzu specifications (typically 200-900 ohms, but verify with service manual). Check for continuity in the wiring from sensor to ECM connector. Inspect for voltage drop or short circuits to ground. Corroded connector pins are extremely common failure points on older machines.

Step 3: Sensor Air Gap Verification Measure the air gap between the sensor tip and the reluctor wheel using a feeler gauge (specification typically 0.5-1.2mm). Incorrect gap causes weak or erratic signals.

Step 4: Component Replacement If testing confirms sensor failure, replace with an OEM or high-quality aftermarket CKP sensor. Clear the code using diagnostic software compatible with Hitachi excavators and perform a test run.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual for your specific machine serial number and seek professional diesel technician assistance for complex electrical diagnostics or engine-internal issues.