What is Kobelco SK350LC-8 Fault Code A245?

Fault Code A245 on the Kobelco SK350LC-8 excavator indicates a malfunction in the Revolution Sensor Circuit, specifically detecting an abnormal signal or voltage irregularity from the engine speed sensor system. This code triggers when the Electronic Control Module (ECM) receives erratic, out-of-range, or no signal from the revolution sensor that monitors engine RPM and crankshaft position.

This sensor is critical for the SK350LC-8's Isuzu AU-6HK1X engine management system. The revolution sensor provides real-time data to synchronize fuel injection timing, adjust throttle response, and coordinate the hydraulic pump output with engine load. When this circuit fails, the excavator's performance, fuel efficiency, and hydraulic responsiveness are significantly compromised, potentially causing the machine to enter a protective derate mode or fail to start altogether.

Common Symptoms

When Code A245 is active on your Kobelco SK350LC-8, operators typically experience:

• Engine warning light illuminated on the monitor panel, often accompanied by audible alarm
• Erratic engine RPM fluctuations or inability to maintain consistent idle speed
• Reduced hydraulic power and sluggish boom/arm movements due to improper pump compensation
• Hard starting conditions or intermittent no-start situations, especially after the machine has warmed up
• Engine stalling during low-idle operation or when engaging hydraulic functions under load

Potential Causes

The most common technical failures triggering A245 on used SK350LC-8 excavators include:

• Revolution sensor failure due to internal component degradation, heat exposure, or magnetic pickup contamination from metal debris
• Wiring harness damage at known rub points near the engine bell housing or along the right-side frame rail where vibration causes insulation wear
• Corroded or loose connector pins at the sensor plug (3-pin connector), particularly on machines operated in marine or mining environments
• ECM power supply issues affecting the 5-volt reference voltage sent to the sensor circuit
• Crankshaft trigger wheel damage or excessive air gap between sensor tip and reluctor ring (should be 0.5-1.5mm)
• Aftermarket sensor incompatibility on machines where non-OEM replacement parts were previously installed

How to Troubleshoot and Fix Code A245

Step 1: Visual Inspection and Connector Check Locate the revolution sensor mounted on the engine block near the flywheel housing (driver's side). Inspect the wiring harness for abrasion, cuts, or heat damage along its entire length to the ECM. Disconnect the 3-pin connector and examine for corrosion, bent pins, or moisture intrusion. On used excavators, this connector frequently suffers from vibration-induced wear—clean contacts with electrical cleaner and apply dielectric grease.

Step 2: Sensor Resistance and Air Gap Verification Using a digital multimeter, measure resistance across the sensor terminals (typically 150-300 ohms at 20°C for OEM Kobelco sensors). Check the physical air gap between sensor tip and flywheel teeth using feeler gauges—excessive gap (over 2mm) indicates worn mounting or damaged trigger wheel. Replace sensor if resistance is out of specification.

Step 3: Circuit Voltage and ECM Signal Testing With ignition on (engine off), backprobe the sensor connector and verify 5-volt reference supply from the ECM. Crank the engine while monitoring AC voltage output from the sensor (should produce 1-10VAC fluctuating signal). If reference voltage is absent, trace wiring back to ECM connector C101, checking for open circuits. For advanced diagnostics, use Kobelco VCADS-III diagnostic software to monitor live sensor data and compare against factory parameters.

Step 4: Address Used Equipment-Specific Issues Before replacing components, inspect for common wear patterns on older SK350LC-8s: check engine ground straps for corrosion (poor grounds cause voltage irregularities), examine harness routing where it passes near the hydraulic pump (heat degradation zone), and verify no aftermarket engine modifications have altered sensor positioning.

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Disclaimer: This guide provides general troubleshooting information for Code A245. Always consult the official Kobelco service manual for your specific serial number, and consider professional diagnostic assistance for complex electrical issues. Improper repairs may void warranties or cause additional component damage.