What is Kobelco SK140LC-8 Fault Code 06568?

Fault Code 06568 on the Kobelco SK140LC-8 excavator indicates a malfunction in the engine oil pressure sensor circuit or excessively low oil pressure detected by the Electronic Control Module (ECM). This diagnostic trouble code (DTC) is triggered when the ECM receives voltage readings outside the normal operating range from the oil pressure sensor, or when actual oil pressure falls below the minimum threshold required for safe engine operation.

This code is critical for the Kobelco SK140LC-8's Isuzu engine because proper oil pressure monitoring prevents catastrophic engine damage. The ECM continuously monitors oil pressure through a dedicated sensor mounted on the engine block. When pressure readings are abnormal, the system may activate protective measures including engine derate or automatic shutdown to prevent bearing wear, scored cylinder walls, or complete engine seizure. For used excavators, this code often appears due to age-related sensor degradation or actual mechanical wear in the lubrication system.

Common Symptoms

When fault code 06568 is active, operators typically experience:

• Oil pressure warning light illuminated on the instrument cluster (typically red)
• Engine derate mode activated, limiting power output to 50-70% of normal capacity
• Audible alarm sounding intermittently or continuously in the cab
• Rough engine idle or unusual ticking/knocking sounds indicating potential oil starvation
• In severe cases, automatic engine shutdown after a brief warning period

Potential Causes

The most common technical reasons for code 06568 on used SK140LC-8 machines include:

• Failed oil pressure sensor – internal sensor element deterioration (common after 5,000+ hours)
• Damaged wiring harness – wire chafing at known rub points near the engine mount brackets or starter motor
• Corroded or loose electrical connectors – moisture intrusion in the sensor connector pins
• Low actual engine oil pressure – worn oil pump, clogged oil filter, or excessive bearing clearances
• Incorrect oil viscosity – using wrong grade oil in older machines with increased tolerances
• ECM software glitch – rare, but outdated firmware can cause false readings

How to Troubleshoot and Fix Code 06568

Step 1: Visual Inspection Begin with a thorough inspection of the oil pressure sensor and its wiring harness. Located on the driver's side of the engine block near the oil filter housing, check for oil contamination on the connector, broken wires, or physical damage. On used excavators, inspect for harness chafing where the wire bundle contacts the engine block during vibration—a common failure point on this model.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor and measure resistance across the sensor terminals. Typical readings should be 50-150 ohms at room temperature (refer to Kobelco service manual for exact specs). Then check for supply voltage at the harness connector—should read approximately 5 volts with ignition on. Also verify continuity between the sensor ground and chassis ground (less than 1 ohm).

Step 3: Verify Actual Oil Pressure Install a mechanical oil pressure gauge in the sensor port to confirm actual pressure. At idle (warm engine), pressure should be minimum 10-15 PSI; at high idle (1,800 RPM), expect 40-60 PSI. If mechanical pressure is low, investigate the oil pump, check oil level/condition, and inspect for internal engine wear—particularly important on high-hour used machines.

Step 4: Component Replacement and Calibration If diagnostics confirm sensor failure, replace with a genuine Kobelco/Isuzu oil pressure sensor (part number specific to SK140LC-8). After installation, clear the fault code using Kobelco diagnostic software (INSITE or compatible tool). Test run the machine under load to verify the repair. For used excavators with persistent codes despite new sensors, consider ECM reprogramming or harness replacement.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Kobelco service manual for your specific machine serial number, and consider professional diagnostic assistance for complex electrical or engine internal issues.