Komatsu PC210LC-10 Fault Code E-35: Complete Diagnostic Guide

What is Komatsu PC210LC-10 Fault Code E-35?

Fault Code E-35 on the Komatsu PC210LC-10 indicates a malfunction in the engine oil pressure sensor circuit or abnormally low engine oil pressure detected by the Engine Control Module (ECM). This code triggers when the ECM receives voltage signals outside the expected range from the oil pressure sensor, or when actual oil pressure falls below critical operating thresholds.

This fault is critical for the PC210LC-10's SAA6D107E-1 engine because inadequate oil pressure can cause catastrophic internal damage to bearings, camshafts, and turbocharger components. The ECM may initiate engine derate or automatic shutdown protocols to prevent severe mechanical failure. On used excavators, this code frequently appears due to sensor degradation or actual mechanical wear in the lubrication system.

Common Symptoms

When Code E-35 is active, operators typically experience:

• Red oil pressure warning light illuminated on the instrument cluster with audible alarm
• Engine power reduction (derate mode) limiting maximum RPM to approximately 1,500-1,800 RPM
• Automatic engine shutdown after a brief warning period if pressure remains critically low
• Intermittent code activation during cold starts or at idle, particularly in high-hour machines
• Visible oil pressure gauge reading below 50 kPi (7 psi) at idle or under 280 kPa (40 psi) at rated speed

Potential Causes

The most common technical causes for E-35 on used PC210LC-10 excavators include:

• Oil pressure sensor failure due to internal diaphragm deterioration or contamination (Komatsu part #6754-21-8110)
• Wiring harness damage at the sensor connector, especially where the harness runs along the engine block near heat sources
• Low engine oil level or use of incorrect viscosity oil for operating conditions
• Worn oil pump or relief valve stuck open, common in machines exceeding 8,000 operating hours
• Excessive bearing clearances in main or rod bearings due to normal wear
• Clogged oil filter or suction screen restricting flow to the pump
• ECM connector corrosion at pins related to the oil pressure sensor circuit (Connector E-12)

How to Troubleshoot and Fix Code E-35

Step 1: Verify Actual Oil Condition and Level Check engine oil level with the machine on level ground and engine off for 10 minutes. Inspect oil quality for metallic contamination or excessive dilution. On used excavators, verify the correct 15W-40 oil specification and proper fill level between marks.

Step 2: Inspect Oil Pressure Sensor and Wiring Locate the oil pressure sensor on the left side of the engine block near the oil filter housing. Disconnect the 2-pin connector and inspect for corrosion, moisture, or bent pins. Check sensor resistance with a digital multimeter: should read approximately 100-300 ohms at room temperature. Inspect wiring for harness rub points against engine brackets—a known wear location on high-hour machines.

Step 3: Perform Voltage Circuit Test With ignition ON and sensor disconnected, measure voltage at the ECM supply wire (typically pin 1): should read 4.8-5.2 volts. Check ground circuit continuity to ECM. Resistance should be less than 1 ohm.

Step 4: Install Mechanical Pressure Gauge Remove the oil pressure sensor and install a calibrated mechanical oil pressure gauge into the sensor port. Start the engine and verify actual pressure: should be 50-100 kPa at idle and 400-500 kPa at high idle. If pressure is adequate, replace the sensor. If low, investigate oil pump, relief valve, or bearing wear.

Step 5: Clear Code and Monitor Using Komatsu KOMPICS diagnostic software or equivalent, clear the fault code and monitor live oil pressure data during operation. On used equipment, verify no intermittent connector issues by wiggle-testing harnesses while monitoring.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Komatsu PC210LC-10 service manual and consider professional inspection, especially when dealing with critical engine protection systems on used heavy equipment.