What is Kobelco SK75-8 Fault Code A245?

Fault Code A245 on the Kobelco SK75-8 excavator indicates a malfunction in the engine preheating system, specifically related to the glow plug relay circuit or glow plug operation. This code is triggered when the Electronic Control Module (ECM) detects abnormal resistance, voltage, or current flow in the glow plug circuit during the preheating cycle. The glow plug system is critical for cold starting diesel engines, as it heats the combustion chambers to facilitate ignition in low-temperature conditions. When this system fails, the SK75-8's starting reliability and engine performance are significantly compromised, particularly in colder climates or after extended periods of inactivity.

Common Symptoms

When Code A245 is active on your Kobelco SK75-8, you may experience:

• Hard starting or failure to start, especially in cold weather or morning startups
• Excessive white or gray smoke during initial startup due to incomplete combustion
• Engine warning light illuminated on the instrument panel
• Rough idle or engine misfiring immediately after cold starts
• Extended cranking time before the engine fires up properly

Potential Causes

Several technical issues can trigger Code A245 on used SK75-8 excavators:

• Failed glow plug relay causing no power delivery to the glow plugs
• Burned out or damaged individual glow plugs (common after 3,000+ operating hours)
• Corroded or loose electrical connections at the glow plug harness, particularly at connector points near the engine block where moisture accumulates
• Damaged wiring harness from rubbing against engine components or heat exposure
• Faulty ECM internal circuitry related to glow plug control (less common)
• Low battery voltage preventing adequate power supply to the preheating system
• Blown fuse or damaged fusible link in the glow plug power circuit

How to Troubleshoot and Fix Code A245

Step 1: Visual Inspection Begin by inspecting all glow plug wiring harnesses and connectors for visible damage, corrosion, or oil contamination. On used excavators, check where harnesses route near hot exhaust components or sharp edges. Clean all connectors with electrical contact cleaner and ensure tight connections.

Step 2: Test Glow Plug Resistance Disconnect each glow plug connector and use a digital multimeter to measure resistance between the glow plug terminal and ground. Typical resistance should be 0.5-2.0 ohms. Any glow plug reading infinite resistance (open circuit) or near-zero resistance (short circuit) must be replaced.

Step 3: Check Glow Plug Relay Operation Locate the glow plug relay (typically in the fuse/relay box). With the key in the ON position, listen for an audible click. Use your multimeter to verify 12V power at the relay output terminal during the preheat cycle (usually 5-15 seconds). If no voltage is present, test relay coil resistance and replace if defective.

Step 4: Verify ECM Signal and Battery Voltage Using Kobelco-compatible diagnostic software (or a professional scan tool), monitor live data during glow plug activation. Confirm the ECM is sending the activation signal and that battery voltage remains above 11.5V during cranking. On older machines, weak batteries often cause intermittent glow plug failures.

Step 5: Clear Code and Test After repairs, clear the fault code using diagnostic software and perform multiple cold-start tests to verify proper operation.

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Disclaimer: This guide provides general troubleshooting information. Always consult the Kobelco SK75-8 service manual and consider professional diagnostics for complex electrical issues or if you're uncertain about procedures.