What is Hitachi ZX470LCH-5G Fault Code 20113-2?

Fault Code 20113-2 on the Hitachi ZX470LCH-5G indicates a hydraulic pump solenoid valve circuit malfunction, specifically a short circuit to ground or open circuit condition in the proportional control solenoid for the main hydraulic pump. This code is generated when the machine's Electronic Control Unit (ECU) detects abnormal electrical resistance or voltage values outside the specified range of 10-30 ohms for the solenoid circuit.

This fault is critical because the proportional solenoid directly controls hydraulic pump displacement and flow rate. When this circuit fails, the excavator loses precise control over hydraulic power output, significantly impacting digging force, swing speed, and overall machine productivity. The ZX470LCH-5G's advanced hydraulic management system relies on continuous feedback from this solenoid to optimize fuel efficiency and performance.

Common Symptoms

• Reduced hydraulic power across all functions, with noticeably slower bucket and arm movements
• Amber hydraulic warning light illuminated on the instrument cluster with audible alarm
• Engine auto-derating to protect the hydraulic system, limiting RPM to approximately 1,400-1,600
• Erratic pump response where hydraulic pressure fluctuates unpredictably during operation
• Complete loss of fine control in precision work, making grading or delicate lifting operations nearly impossible

Potential Causes

The most common technical causes for Code 20113-2 on used ZX470LCH-5G excavators include:

• Damaged wiring harness at the pump mounting area where cable routing experiences vibration and heat exposure from the engine
• Corroded connector pins at the solenoid valve plug (6-pin Deutsch connector), particularly on machines operating in coastal or high-humidity environments
• Failed proportional solenoid coil due to internal winding breakdown after 8,000+ operating hours
• Chafed wires near the pump pedestal where harnesses contact sharp metal edges during engine torque movement
• ECU internal driver circuit failure, though less common, seen in machines with electrical system overvoltage history
• Contaminated hydraulic oil causing solenoid valve spool sticking, creating abnormal current draw

How to Troubleshoot and Fix Code 20113-2

Step 1: Visual Inspection Begin by disconnecting the battery negative terminal. Locate the main hydraulic pump on the left side of the engine. Inspect the solenoid valve wiring harness for obvious damage, particularly where it passes near the engine mount. Check the 6-pin connector for corrosion, moisture intrusion, or bent pins. On used excavators, this connector frequently shows green corrosion on terminals.

Step 2: Electrical Testing Using a quality digital multimeter, disconnect the solenoid connector and measure resistance across the solenoid coil terminals. Specification is 10-30 ohms at 20°C. Next, check for short to ground by measuring resistance between each solenoid terminal and the pump body (should read infinite resistance/open circuit). If readings are out of specification, the solenoid valve requires replacement (Hitachi part number 4642095).

Step 3: Wiring Harness Verification With the solenoid disconnected, measure continuity from the ECU connector pins (terminals 47 and 48 on the main engine harness connector) to the pump solenoid plug. Resistance should be less than 2 ohms. Check for intermittent shorts by flexing the harness while monitoring resistance. For used machines, pay special attention to harness routing—reroute and secure with new clamps if wear marks are visible.

Step 4: Power Supply Check Reconnect all components and use the multimeter to verify the solenoid receives proper 12-24V DC supply voltage when the ignition is on. If voltage is absent, trace back to the ECU and check fuse F7 (20A) in the main fuse box.

Step 5: Clear Code and Test After repairs, use Hitachi Dr.EX diagnostic software or equivalent scan tool to clear the fault code. Operate the machine through full hydraulic cycles for 15 minutes while monitoring for code recurrence.

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Disclaimer: This guide provides general troubleshooting information. Hydraulic systems operate under extreme pressure. Always consult the official Hitachi service manual for your specific serial number and consider professional diagnostic assistance for complex electrical issues. Improper repairs may cause catastrophic hydraulic system failure or personal injury.