Komatsu PC120LC-6 Fault Code E213: Complete Diagnostic Guide

What is Komatsu PC120LC-6 Fault Code E213?

Fault Code E213 on the Komatsu PC120LC-6 indicates a malfunction in the engine speed sensor circuit, specifically detecting an abnormal signal or open circuit condition from the engine RPM sensor.

This fault code is generated by the Engine Control Module (ECM) when it fails to receive a valid signal from the magnetic pickup sensor mounted on the flywheel housing. The engine speed sensor is critical for monitoring crankshaft rotation and providing real-time RPM data to the fuel injection system.

On the PC120LC-6 equipped with the SAA4D95LE-3 engine, accurate speed sensing is essential for proper fuel timing, governor control, and overall machine performance. Without this signal, the ECM cannot regulate injection timing correctly.

Common Symptoms

• Engine stalling or failure to start, particularly intermittent no-start conditions
• Erratic idle behavior with RPM fluctuations or hunting
• Reduced engine power and sluggish hydraulic response
• Warning indicator illumination on the monitor panel
• Engine runs rough or misfires under varying loads

Potential Causes

The most frequent causes of E213 on used PC120LC-6 units include:

• Damaged engine speed sensor due to age or contamination from oil leaks
• Corroded or loose connector pins at the sensor harness junction
• Wiring harness damage from friction against the flywheel housing or engine block
• Incorrect sensor air gap caused by mounting bolt loosening over time
• ECM input circuit failure (less common but possible on high-hour machines)

On older units, pay particular attention to harness routing near hot engine components where insulation breakdown commonly occurs.

How to Troubleshoot and Fix Code E213

Step 1: Visual Inspection Locate the engine speed sensor on the flywheel housing. Inspect the sensor connector for corrosion, moisture intrusion, or bent pins. Check the wiring harness for abrasion, particularly where it routes past the engine block.

Step 2: Electrical Testing Using a multimeter, measure sensor resistance across the signal terminals. The specification should read 190-250 ohms at room temperature. Test for continuity between the harness and ECM connector to rule out open circuits.

Step 3: Signal Verification With Komatsu VHMS or diagnostic software, monitor live sensor data while cranking. Alternatively, use an oscilloscope to verify the sensor produces a clean AC voltage signal during engine rotation.

Step 4: Gap and Mounting Check Verify the sensor air gap is within 0.5-1.5mm from the flywheel ring gear teeth. Tighten mounting hardware to specification and clean any metallic debris from the sensor tip.

Important Note for Used Equipment: Before replacing components, thoroughly inspect all connectors for oxidation and wiring for hidden damage caused by previous repairs or environmental exposure.

---

Disclaimer: This guide is for informational purposes. Always consult factory service documentation and qualified technicians for complex repairs.