Komatsu PC210-8 Fault Code S-13: Complete Diagnostic Guide

What is Komatsu PC210-8 Fault Code S-13?

Fault Code S-13 on the Komatsu PC210-8 excavator indicates a malfunction in the engine speed sensor circuit. This code is triggered when the Electronic Control Module (ECM) detects an abnormal signal or loss of communication from the crankshaft position sensor or engine speed sensor.

The engine speed sensor is critical for the PC210-8's SAA6D107E-1 engine because it provides real-time data to the ECM regarding crankshaft rotation speed and position. This information controls fuel injection timing, engine RPM regulation, and overall combustion efficiency. When this sensor circuit fails, the machine cannot operate properly, potentially leading to severe performance degradation or complete shutdown.

Common Symptoms

When Code S-13 is active on your Komatsu PC210-8, you may experience:

• Engine cranks but fails to start or starts and immediately stalls
• Monitor panel displays warning icon with reduced engine power (derate mode)
• Erratic engine RPM fluctuations during operation, especially at idle
• Loss of hydraulic power due to improper fuel delivery and inconsistent engine speed
• Black smoke from exhaust caused by incorrect fuel injection timing

Potential Causes

The most common technical reasons for S-13 on used PC210-8 excavators include:

• Damaged or worn engine speed sensor due to heat stress, vibration, or contamination from oil/coolant leaks
• Corroded or loose wiring connectors at the sensor harness, particularly the 3-pin connector near the flywheel housing
• Broken or chafed sensor wiring caused by harness rubbing against the engine block or bell housing (known issue on high-hour machines)
• Contaminated sensor gap with metal shavings, dirt, or oil buildup affecting magnetic field detection
• Failed ECM input circuit or internal ECM fault (rare, but possible on older machines)
• Damaged flywheel teeth or reluctor wheel preventing proper signal generation

How to Troubleshoot and Fix Code S-13

Step 1: Visual Inspection Locate the engine speed sensor on the left side of the engine near the flywheel housing. Inspect the sensor body for physical damage, oil contamination, or mounting looseness. Check the wiring harness from sensor to ECM for abrasion points, especially where it routes along the engine block. On used excavators, look specifically for harness chafing against metal edges or heat-damaged insulation near the turbocharger.

Step 2: Electrical Testing Disconnect the sensor's 3-pin connector. Using a digital multimeter, measure the sensor's resistance between terminals. The PC210-8 engine speed sensor should typically read 150-300 ohms at room temperature (consult your service manual for exact specifications). Check for continuity in the harness wiring back to the ECM connector. Measure voltage supply from the ECM (should be approximately 5-12V DC depending on circuit design).

Step 3: Sensor Gap and Condition Remove the sensor completely and inspect the sensing tip for metal debris or oil buildup. Clean with electrical contact cleaner. Verify the air gap between the sensor tip and flywheel teeth is within specification (0.5-1.5mm typically). On high-hour used machines, inspect the flywheel reluctor ring for missing or damaged teeth using a borescope if necessary.

Step 4: Component Replacement and Verification If testing reveals a faulty sensor, replace with a genuine Komatsu part (Part #600-815-8870 or equivalent). After installation, clear the fault code using Komatsu diagnostic software (KOMTRAX Plus) or a compatible diagnostic scan tool. Perform a regeneration test by cranking the engine and verifying the ECM receives proper signal. For used excavators with recurring codes, consider replacing the entire sensor harness assembly to eliminate corrosion-related intermittent faults.

Disclaimer: This guide provides general diagnostic information. Always consult the official Komatsu service manual for your specific machine serial number. If you lack proper diagnostic tools or experience with high-pressure fuel systems, seek assistance from a certified Komatsu technician to avoid injury or further damage.