What is Komatsu PC360-7 Fault Code E113?

Fault Code E113 on the Komatsu PC360-7 excavator indicates a malfunction in the engine oil pressure sensor circuit or an abnormal engine oil pressure reading detected by the Engine Control Module (ECM). This diagnostic trouble code specifically signals that the ECM has detected voltage values outside the acceptable range from the oil pressure sensor, or that actual oil pressure has fallen below critical thresholds during operation.

This code is particularly critical for the PC360-7's SAA6D114E-2 engine because proper oil pressure monitoring protects against catastrophic engine damage. The ECM uses oil pressure data to regulate engine speed, activate warning systems, and in severe cases, initiate engine derate or shutdown to prevent bearing failure, crankshaft damage, or complete engine seizure. On used excavators with higher operating hours, this fault becomes increasingly common due to sensor degradation and harness wear.

Common Symptoms

• Oil pressure warning lamp illuminated on the instrument cluster, often accompanied by audible alarm
• Engine derate mode activated, limiting maximum RPM to approximately 1,500-1,800 to protect engine components
• Erratic oil pressure gauge readings that fluctuate abnormally or display zero pressure despite engine running normally
• Intermittent fault code that appears and disappears, especially during cold starts or after extended idle periods
• Engine auto-shutdown in severe cases where the ECM determines oil pressure is dangerously low

Potential Causes

The most common technical causes for Code E113 on used PC360-7 excavators include:

• Failed oil pressure sensor (Komatsu part #6732-81-3140) due to internal diaphragm deterioration or electrical element failure
• Damaged wiring harness between the sensor and ECM, particularly at the harness routing point near the engine mount where vibration causes insulation wear
• Corroded or loose electrical connectors at the sensor terminals or ECM pins, especially on machines operated in wet or coastal environments
• Low actual engine oil pressure caused by worn oil pump, excessive bearing clearances, or blocked oil passages in high-hour machines
• ECM internal fault or corrupted software, though significantly less common than sensor/harness issues
• Incorrect oil viscosity or severely degraded engine oil reducing actual pressure below sensor threshold

How to Troubleshoot and Fix Code E113

Step 1: Visual Inspection and Preliminary Checks Begin by locating the oil pressure sensor on the right side of the engine block near the oil filter housing. Inspect the sensor connector for corrosion, oil contamination, or damaged pins—a frequent issue on used excavators. Check engine oil level and condition; degraded oil or low levels can cause genuine pressure problems. Examine the wiring harness from sensor to ECM for obvious damage, especially where it passes mounting brackets or rubs against the frame.

Step 2: Electrical Circuit Testing Disconnect the oil pressure sensor connector and use a digital multimeter to check sensor resistance. The sensor should typically read 50-150 ohms at room temperature (consult your service manual for exact specifications). Next, test circuit continuity from the sensor connector to ECM pins and check for short circuits to ground. Measure supply voltage at the sensor connector with ignition on—you should see approximately 5 volts from the ECM reference circuit.

Step 3: Sensor Replacement and Verification If electrical values are out of specification or the sensor shows internal resistance faults, replace with a genuine Komatsu oil pressure sensor. For used excavators, always apply dielectric grease to connector terminals before reassembly to prevent future corrosion. After installation, clear codes using Komatsu diagnostic software (KOMTRAX) or a compatible scanner, then operate the machine through various load conditions while monitoring live oil pressure data to confirm repair.

Step 4: Verify Actual Oil Pressure If the fault persists after sensor replacement, install a mechanical oil pressure gauge at the sensor port to verify actual engine oil pressure. At normal operating temperature and 1,800 RPM, pressure should read 280-430 kPa (40-62 PSI). Low readings indicate internal engine problems requiring major service—common in excavators exceeding 8,000-10,000 operating hours.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Komatsu PC360-7 service manual for complete diagnostic procedures and specifications. If you lack proper diagnostic tools or experience with heavy equipment electrical systems, consult a certified Komatsu technician to prevent misdiagnosis or additional damage.