What is Hitachi ZX210LC-5G-HCMC Fault Code 13304-2?

Fault Code 13304-2 indicates a hydraulic pump solenoid valve circuit malfunction, specifically detecting an abnormal current flow or open circuit condition in the main pump control solenoid. This code is generated when the Engine Control Module (ECM) detects that the electrical signal to the hydraulic pump's proportional solenoid valve is outside the manufacturer's specified parameters, typically between 0.5-4.5 volts.

In the Hitachi ZX210LC-5G-HCMC excavator, this solenoid directly controls the swash plate angle of the main hydraulic pump, which regulates hydraulic flow and pressure throughout the entire machine. When this circuit fails, the excavator's ability to manage engine load matching and hydraulic performance is severely compromised, potentially causing catastrophic pump damage if left unaddressed.

Common Symptoms

• Reduced hydraulic power across all functions, with noticeably slower boom, arm, and swing operations
• Engine over-revving without corresponding increases in hydraulic performance due to loss of pump load-sensing capability
• Amber hydraulic warning light illuminated on the instrument cluster, often accompanied by audible warning beeps
• Erratic hydraulic response where the machine intermittently loses power during digging or lifting operations
• Limp mode activation where the ECM limits engine RPM to protect the hydraulic system from damage

Potential Causes

On used ZX210LC-5G-HCMC excavators, this fault code typically stems from:

• Corroded or damaged wiring harness connectors at the pump solenoid interface, especially where the harness passes near the engine mounting points (known rub point on this model)
• Failed proportional solenoid valve coil due to heat exposure from prolonged operation or internal short circuits
• Broken or frayed wiring in the engine compartment harness, particularly between the ECM and pump assembly
• ECM internal driver circuit failure, less common but occurs in high-hour machines (8,000+ hours)
• Contaminated electrical connections from hydraulic oil mist or coolant leaks affecting the 12-pin pump connector

How to Troubleshoot and Fix Code 13304-2

Step 1: Visual Inspection of Wiring and Connectors Begin by disconnecting the battery and inspecting the 12-pin connector at the hydraulic pump solenoid. On used excavators, check for green corrosion, bent pins, or oil contamination. Inspect the entire harness route from the ECM (located behind the operator's seat) to the pump for chafing, especially where it contacts the engine block.

Step 2: Electrical Testing with Multimeter Using a digital multimeter, measure the solenoid coil resistance directly at the pump connector (pins 3 and 7). Specification should read 3-5 ohms at room temperature. Next, check for supply voltage from the ECM with the key in the "ON" position—you should see 12V DC at pin 3. Measure ground continuity at pin 7, which should show less than 0.5 ohms resistance to chassis ground.

Step 3: Advanced Diagnostics with Hitachi Dr.EX Software Connect Hitachi Dr.EX diagnostic software via the machine's diagnostic port. Monitor live data for the solenoid valve command signal versus actual current draw. The ECM should command between 200-800 milliamps depending on load. If command signal is present but current draw is zero, the solenoid coil has failed. If both are absent, suspect ECM driver circuit failure.

Step 4: Component Replacement and Verification For used machines, if wiring and connections test good, replace the proportional solenoid valve assembly (Hitachi part number 4616544). After replacement, clear fault codes using diagnostic software and perform a hydraulic system calibration procedure. Test under load for at least 30 minutes to ensure the code doesn't return.

Critical for Used Equipment: Before replacing the solenoid valve ($450-$650), thoroughly clean all electrical connections with electrical contact cleaner and apply dielectric grease. Approximately 40% of these codes on used excavators resolve through connector maintenance alone.

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Disclaimer: This guide provides general troubleshooting information. Always consult the Hitachi ZX210LC-5G service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs may void warranties or cause additional damage.