What is Komatsu PC210-7 Fault Code E113?

Fault Code E113 on the Komatsu PC210-7 indicates a malfunction in the hydraulic oil temperature sensor circuit. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects an abnormal voltage signal from the temperature sensor monitoring the hydraulic oil in the main hydraulic tank. The sensor provides critical data that the ECM uses to protect the hydraulic system from overheating and optimize performance across all hydraulic functions.

This code is particularly critical for the PC210-7 because excessive hydraulic oil temperature can lead to accelerated seal deterioration, reduced hydraulic efficiency, and potential damage to expensive components like the main hydraulic pump and control valves. The ECM relies on accurate temperature readings to trigger cooling system responses and alert operators before catastrophic failures occur.

Common Symptoms

When Code E113 is active on your Komatsu PC210-7, you may experience:

• Hydraulic oil temperature warning light illuminated on the instrument cluster, often accompanied by an audible alarm
• Reduced hydraulic performance or sluggish operation of boom, arm, and bucket functions as the ECM enters protective derate mode
• Erratic temperature gauge readings that fluctuate abnormally or remain at minimum/maximum positions regardless of actual operating conditions
• Intermittent code activation that appears and disappears, particularly when operating over rough terrain (indicating potential wiring issues)
• Fan operation abnormalities, with the hydraulic cooling fan running continuously or failing to engage when hydraulic temperatures rise

Potential Causes

The most common technical causes for E113 on used PC210-7 excavators include:

• Failed hydraulic oil temperature sensor due to internal element degradation or moisture intrusion (typical failure point after 8,000-12,000 operating hours)
• Damaged or corroded wiring harness connections at the sensor connector, especially where the harness routes near the hydraulic tank and experiences vibration and heat cycling
• Harness chafing at known rub points where the sensor wiring passes through frame brackets near the left side track frame (common wear area on this model)
• Corroded pins or moisture in the ECM connector where the temperature sensor circuit terminates
• ECM internal circuit failure (rare, but possible in high-hour machines exposed to extreme environments)
• Improper sensor installation after previous repairs, causing poor thermal contact with hydraulic oil

How to Troubleshoot and Fix Code E113

Step 1: Visual Inspection and Connector Check Begin by locating the hydraulic oil temperature sensor on the left side of the main hydraulic tank. Disconnect the sensor connector and thoroughly inspect both the sensor pins and harness connector for corrosion, bent pins, or oil contamination. On used excavators, this connector often accumulates moisture. Clean with electrical contact cleaner and apply dielectric grease before reconnection. Inspect the wiring harness from sensor to ECM for obvious damage, paying special attention to areas where the harness contacts frame members.

Step 2: Sensor Resistance Testing Using a digital multimeter (DMM), measure the resistance across the sensor terminals with the sensor at ambient temperature. The PC210-7 hydraulic temperature sensor should read approximately 2,000-3,000 ohms at 20°C (68°F). Compare your reading to Komatsu specifications using the temperature-resistance chart in the service manual. If resistance is out of specification, infinite, or zero ohms, replace the sensor with a genuine Komatsu part (7861-93-3320) or OEM equivalent.

Step 3: Circuit Voltage and Continuity Check With the sensor disconnected and ignition on (engine off), measure supply voltage at the harness connector. You should see approximately 5 volts from the ECM reference circuit. Check ground continuity on the return circuit (should be less than 1 ohm to chassis ground). If voltage or ground readings are incorrect, trace the harness back to the ECM connector (located behind the operator cab), checking for breaks in continuity or shorts to ground. On used machines, harness damage often occurs where cables pass through grommets in bulkheads.

Step 4: Advanced Diagnostics with Komatsu Software Connect Komatsu diagnostic software (KOMATSU PC Service Tool) to monitor real-time sensor data. Observe the temperature reading while gently heating the sensor with a heat gun (carefully, to approximately 50-60°C). The displayed temperature should rise correspondingly. If the software shows fixed values, "open circuit," or "short circuit" messages despite a good sensor, suspect ECM connector corrosion or internal ECM failure.

Critical Note for Used Excavators: Before replacing any components, thoroughly inspect all harness routing for wear patterns, previous repairs, or incorrect routing after prior service work. Many E113 codes on higher-hour PC210-7s result from harness degradation rather than sensor failure. Always verify wiring integrity before part replacement.

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Disclaimer: This guide provides general troubleshooting information for Code E113. Hydraulic and electrical system diagnostics require proper training and safety precautions. Always consult the official Komatsu service manual for your specific machine serial number and consider professional diagnosis for complex electrical issues or if you're unfamiliar with high-voltage electrical systems.