What is Kobelco SK140LC-8 Fault Code 16708?

Fault Code 16708 on the Kobelco SK140LC-8 excavator indicates a malfunction in the hydraulic pump solenoid valve circuit, specifically related to the pilot pressure control system. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects an abnormal electrical signal—either an open circuit, short circuit, or irregular voltage—in the pump control solenoid wiring harness or the solenoid valve itself.

This code is critical because the pilot pressure control solenoid regulates hydraulic pump output based on load demand and operator input. When this circuit malfunctions, the excavator's hydraulic system cannot properly modulate pressure and flow, directly affecting machine performance, fuel efficiency, and responsiveness during digging, lifting, and swing operations.

Common Symptoms

When fault code 16708 is active on your SK140LC-8, operators typically experience:

• Reduced hydraulic power across all functions, with noticeably slower boom, arm, and bucket movements
• Erratic engine RPM fluctuations during loaded operations or sudden power drops
• Warning lamp illumination on the instrument cluster, often accompanied by audible alerts
• Loss of fine control during precision work, as the pump fails to adjust output smoothly
• Increased fuel consumption due to the pump running at fixed displacement instead of load-sensing mode

Potential Causes

The most common technical failures triggering this code in used SK140LC-8 excavators include:

• Solenoid valve coil failure due to age-related insulation breakdown or internal short circuits (common after 5,000+ operating hours)
• Corroded or damaged wiring connectors at the pump solenoid harness junction, especially where the harness routes near the hydraulic tank
• Chafed wiring caused by vibration rubbing against the pump assembly or cab-to-chassis flex points
• ECM voltage supply issues, including poor ground connections at the controller or main battery terminals
• Water intrusion into the solenoid connector from pressure washing or damaged seals
• Failed ECM output driver circuit, though less common than external wiring problems

How to Troubleshoot and Fix Code 16708

Step 1: Initial Visual Inspection Before electrical testing, physically inspect the solenoid valve connector located on the main hydraulic pump assembly. Look for corrosion (green/white deposits), moisture, bent pins, or loose connections. On used excavators, this connector frequently fails due to environmental exposure and should be cleaned with electrical contact cleaner.

Step 2: Electrical Continuity Testing Using a digital multimeter (DMM), disconnect the solenoid connector and measure resistance across the solenoid coil terminals. A healthy coil typically reads 12-18 ohms (verify exact specification in Kobelco service manual). An open circuit (infinite resistance) or near-zero resistance indicates coil failure requiring solenoid replacement.

Step 3: Harness and Voltage Checks With ignition ON and engine OFF, measure supply voltage at the solenoid connector—you should see approximately 12V DC. Check continuity between the ground wire and chassis ground (should be less than 1 ohm). Inspect the entire harness from the ECM to the pump, particularly where it passes through rubber grommets or near sharp edges—common wear points on the SK140LC-8.

Step 4: ECM Signal Verification If wiring and solenoid test normal, connect Kobelco-compatible diagnostic software (such as Kobelco Diagnostics System) to monitor ECM output signals in real-time. Command the solenoid ON/OFF while monitoring current draw; improper driver response indicates ECM issues.

For used excavators, always examine connector seals, wire insulation condition, and previous repair quality before replacing expensive components. Many code 16708 instances resolve with thorough connector cleaning and harness re-routing.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Kobelco SK140LC-8 service manual and consider professional assistance for complex electrical repairs or if you lack proper diagnostic equipment.