What is Kobelco SK135SRLC-2 Fault Code P0202?

Fault Code P0202 indicates a malfunction in the Injector Circuit for Cylinder 2. This diagnostic trouble code (DTC) means the Engine Control Module (ECM) has detected an abnormal electrical condition in the fuel injector circuit for the second cylinder, either an open circuit, short circuit, or improper resistance value.

In the Kobelco SK135SRLC-2 excavator, this code directly affects the fuel delivery system of the engine. The ECM continuously monitors injector circuits to ensure proper fuel atomization and combustion timing. When the injector circuit for cylinder 2 falls outside specified parameters, the ECM logs P0202 and may initiate protective measures. This is critical because improper fuel injection causes power loss, increased emissions, and potential damage to engine components through incomplete combustion or cylinder washing.

Common Symptoms

When P0202 is active on your SK135SRLC-2, you may experience:

• Check Engine Light or malfunction indicator lamp illuminated on the dashboard
• Noticeable rough idle or engine misfiring, especially at low RPM
• Reduced engine power and sluggish hydraulic response during operation
• Increased fuel consumption and black or white smoke from the exhaust
• Engine running on only three cylinders in severe cases, with distinctive vibration

Potential Causes

The most common technical causes for P0202 in used Kobelco excavators include:

• Faulty fuel injector for cylinder 2 due to coil winding failure or internal mechanical wear
• Damaged wiring harness or corroded connectors between the ECM and injector, particularly at harness rub points near the engine block
• Broken or chafed wires in the injector circuit caused by vibration over years of operation
• ECM internal driver circuit failure for the #2 injector channel
• Poor electrical connections at the injector connector due to moisture ingress or corrosion common in older machines
• Incorrect injector resistance outside manufacturer specifications (typically 0.5-2.0 ohms)

How to Troubleshoot and Fix Code P0202

Step 1: Visual Inspection Begin by inspecting the wiring harness running to cylinder 2's fuel injector. On used excavators, check for worn insulation, particularly where harnesses contact metal surfaces or pass through grommets. Examine the injector connector for corrosion, bent pins, or moisture contamination—common issues after thousands of operating hours.

Step 2: Electrical Testing Using a digital multimeter, perform resistance checks on the #2 injector. Disconnect the injector connector and measure resistance across the injector terminals (typically 0.5-2.0 ohms; consult your service manual). Check for short to ground by measuring resistance between each injector terminal and engine ground—it should read infinite (open circuit).

Step 3: Circuit Continuity Testing With the ECM connector disconnected, check continuity between the ECM pins and the injector connector. Verify there are no shorts between wires. Test supply voltage at the injector connector with ignition on (typically 12-24V depending on system design).

Step 4: Swap Test If available, swap the #2 injector with another cylinder's injector. Clear codes and retest. If P0202 moves to the new location, the injector itself is faulty. If the code remains on cylinder 2, the issue lies in the wiring or ECM.

Step 5: Advanced Diagnostics Use Kobelco diagnostic software or compatible scan tools to perform injector response tests and view live data. Check injector pulse width and compare values across all cylinders.

For used excavators, always inspect harness routing for previous repair attempts, aftermarket splices, or zip-tie damage that may have created new wear points. Replace corroded connectors rather than just cleaning them for long-term reliability.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Kobelco service manual for your specific machine serial number and seek professional assistance from certified technicians for complex electrical diagnostics and repairs.