What is Hitachi ZX350K-5G Fault Code 13310-3?

Fault Code 13310-3 indicates a hydraulic pump control system malfunction, specifically related to the main pump displacement sensor circuit showing an abnormal voltage signal or sensor failure. This diagnostic trouble code (DTC) is generated when the Electronic Control Module (ECM) detects that the pump displacement feedback signal is outside the acceptable voltage range (typically 0.5-4.5V) for more than 2 seconds during operation.

The main pump displacement sensor is critical for the ZX350K-5G's advanced hydraulic system, as it provides real-time feedback to the ECM about pump swash plate angle. This allows the controller to optimize hydraulic flow, fuel efficiency, and machine performance. When this sensor fails or provides erratic signals, the excavator's automatic power mode and pump control functions are severely compromised, potentially leading to reduced productivity and increased fuel consumption.

Common Symptoms

• Reduced hydraulic power across all functions, with noticeably slower boom, arm, and bucket movements
• Yellow warning light illuminated on the instrument cluster with possible audible alarm
• Machine operating in derate mode, limiting engine RPM to approximately 1,500-1,700 RPM
• Erratic hydraulic response when operating multiple functions simultaneously
• Increased fuel consumption due to the ECM defaulting to conservative pump control settings

Potential Causes

The most common causes of Code 13310-3 on used ZX350K-5G excavators include:

• Worn or damaged displacement sensor mounted on the main hydraulic pump housing (common failure point after 6,000+ hours)
• Corroded or loose electrical connectors at the sensor harness connection, particularly where the harness passes near the pump heat shield
• Chafed wiring harness along the right-side frame rail where the sensor cable routes through metal brackets (known rub point on this model)
• Failed ECM power supply circuit providing incorrect reference voltage to the sensor
• Contaminated hydraulic oil causing internal pump wear that affects sensor reading accuracy
• Water intrusion into the sensor connector from pressure washing or operating in wet conditions

How to Troubleshoot and Fix Code 13310-3

Step 1: Visual Inspection and Connector Check Begin by locating the pump displacement sensor on the main hydraulic pump (driver's side of the engine compartment). Disconnect the 3-pin connector and inspect for corrosion, bent pins, or moisture. On used excavators, this connector frequently shows green corrosion due to its proximity to heat and vibration. Clean with electrical contact cleaner and check for proper pin tension.

Step 2: Sensor Resistance and Voltage Testing Using a digital multimeter, measure sensor resistance between pins 1 and 2 with the connector disconnected and ignition off. The resistance should read between 500-1,500 ohms at room temperature. Next, reconnect the sensor and backprobe the signal wire (typically pin 2) with ignition on, engine off. You should see reference voltage of 5V ±0.2V. Any reading outside this range indicates ECM issues or wiring problems.

Step 3: Harness Continuity and Ground Testing Trace the sensor harness from the pump to the ECM, checking for chafing or breaks, especially at known wear points near frame brackets and pump mounting bolts. Test continuity from sensor connector to ECM pins using a wiring diagram. Verify ground integrity by measuring resistance from sensor ground pin to chassis ground (should be less than 1 ohm).

Step 4: Dynamic Testing with Diagnostic Software Connect Hitachi Dr.EX diagnostic software to monitor live sensor data. With the engine running at low idle, the displacement sensor should show smooth voltage changes between 0.8-4.2V as the system modulates. Erratic jumps or frozen readings confirm sensor failure, while consistent out-of-range values suggest ECM calibration issues.

Step 5: Component Replacement Considerations For used machines, always inspect the pump mounting area for oil leaks before replacing the sensor, as hydraulic contamination often causes premature sensor failure. Replace the sensor with a genuine Hitachi part (P/N varies by production date) and apply dielectric grease to the new connector. After replacement, clear codes and perform a pump calibration procedure using diagnostic software to ensure proper system operation.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Hitachi service manual for your specific machine serial number and production year. If you're unfamiliar with hydraulic systems or electrical diagnostics, contact a certified Hitachi dealer or qualified heavy equipment technician to prevent injury or further machine damage.