What is Komatsu PC110-8M0 Fault Code E-11?

Fault Code E-11 on the Komatsu PC110-8M0 indicates a malfunction in the engine oil pressure sensor circuit or abnormally low engine oil pressure. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects either an electrical issue with the oil pressure sensor wiring or an actual hydraulic problem where oil pressure falls below the manufacturer's specified threshold during operation.

This code is critical for the PC110-8M0's SAA4D107E-1 diesel engine because inadequate oil pressure can lead to catastrophic bearing failure, crankshaft damage, and complete engine seizure. The ECM continuously monitors oil pressure to protect internal engine components from friction-related damage. When E-11 activates, the system may initiate protective measures to prevent irreversible mechanical harm.

Common Symptoms

Operators experiencing Code E-11 may notice:

• Audible warning alarm accompanied by a flashing oil pressure warning light on the instrument cluster
• Engine power derate or automatic shutdown after a brief warning period (typically 20-30 seconds)
• Low oil pressure gauge readings during normal operating temperature and RPM
• Unusual engine noise such as valve train ticking or rod knocking if actual oil starvation is occurring
• Intermittent code activation during cold starts or when operating on slopes with low oil levels

Potential Causes

The most common technical reasons for E-11 on used PC110-8M0 excavators include:

• Oil pressure sensor failure due to internal diaphragm degradation (common after 4,000+ operating hours)
• Damaged sensor wiring harness at known rub points near the engine mount bracket and steering valve assembly
• Corroded or loose electrical connectors at the sensor or ECM interface, particularly on machines stored outdoors
• Actual low engine oil level from leaks at the oil cooler gasket or valve cover seals
• Worn oil pump or clogged oil pickup screen reducing system pressure
• Contaminated engine oil with excessive fuel dilution causing viscosity breakdown
• ECM internal fault affecting sensor voltage reference (less common but documented on 2012-2014 production units)

How to Troubleshoot and Fix Code E-11

Step 1: Verify Actual Oil Pressure Using a mechanical oil pressure gauge, connect to the test port on the oil filter housing. Start the engine and compare readings against Komatsu specifications (should be 280-440 kPa at 2,000 RPM when warm). If mechanical pressure is normal, the issue is electrical. If low, investigate the lubrication system directly.

Step 2: Inspect Oil Pressure Sensor and Wiring Locate the oil pressure sensor on the lower left side of the engine block. Disconnect the sensor harness and inspect for:

• Corrosion on connector pins (clean with electrical contact cleaner)
• Harness chafing where it passes over the engine mount (common failure point on used machines)
• Use a digital multimeter to check sensor resistance (typically 100-300 ohms depending on temperature)

Step 3: Test Sensor Signal and Power Supply With the harness connected and ignition on (engine off), backprobe the sensor connector to verify:

• 5-volt reference supply from the ECM (red wire)
• Ground continuity (black wire should show less than 1 ohm to chassis ground)
• Signal voltage should vary between 0.5-4.5 volts when engine is running

Step 4: Replace Components as Needed If sensor tests fail, install a genuine Komatsu oil pressure sensor (Part #56CP-15-01). For wiring issues, repair damaged sections using heat-shrink solder connectors rather than crimp connectors to prevent future corrosion on used equipment. Clear codes using Komatsu diagnostic software (KOMTRAX) or a compatible scanner, then test-run the machine under load.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu PC110-8M0 service manual and consider professional diagnostic assistance for complex electrical or internal engine issues, especially on used machinery with unknown service history.