Komatsu PC800SE-7 Fault Code E213: Complete Diagnostic Guide

What is Komatsu PC800SE-7 Fault Code E213?

Fault Code E213 indicates a malfunction in the engine coolant temperature sensor circuit or an abnormal coolant temperature reading detected by the Engine Control Module (ECM). This code specifically relates to the temperature monitoring system that protects the Komatsu SAA6D140E-7 engine from overheating damage.

The coolant temperature sensor sends voltage signals to the ECM, which uses this data to regulate fuel injection timing, fan speed, and engine protection protocols. When the ECM detects voltage readings outside the normal range (typically 0.5-4.5V) or physically impossible temperature values, it triggers E213. For the PC800SE-7, this is critical because improper temperature management can lead to severe engine damage, reduced hydraulic efficiency, and costly downtime on high-hour used machines.

Common Symptoms

When Code E213 is active, operators typically experience:

• Engine warning light illuminated on the monitor panel with possible audible alarm
• Reduced engine power or automatic derate mode to prevent overheating damage
• Inaccurate temperature gauge readings (showing extremely high, low, or erratic temperatures)
• Cooling fan running continuously at maximum speed regardless of actual engine temperature
• Difficulty starting in cold conditions if the ECM receives false cold-temperature signals

Potential Causes

The most common technical causes for E213 on used PC800SE-7 excavators include:

• Failed coolant temperature sensor due to internal element degradation (common after 8,000+ operating hours)
• Damaged or corroded wiring harness between the sensor and ECM, particularly at connector pins
• Harness chafing at known rub points near the engine block mounting brackets
• Corroded or loose electrical connectors caused by coolant leaks or moisture intrusion
• ECM internal fault (less common, but possible in high-hour machines)
• Poor ground connections at the sensor mounting point due to rust or gasket deterioration

How to Troubleshoot and Fix Code E213

Step 1: Visual Inspection Begin by inspecting the coolant temperature sensor located on the engine block's coolant passage. Check for coolant leaks, corrosion on the connector, and physical damage to the wiring harness. On used excavators, pay special attention to harness routing near moving components where friction wear commonly occurs.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor and measure its resistance. At 20°C (68°F), resistance should typically read 2,000-3,000 ohms (consult your service manual for exact specifications). Test the harness continuity from the sensor connector to the ECM—resistance should be less than 5 ohms. Check for short circuits to ground (should read infinite resistance).

Step 3: Voltage Signal Check With the sensor connected and ignition on (engine off), backprobe the sensor connector using Komatsu diagnostic software (KOMTRAX or PC-compatible interface). The voltage signal should read approximately 4.5-5.0V with a cold engine. If voltage is absent or incorrect, trace the power supply circuit back to the ECM.

Step 4: Component Replacement If testing confirms sensor failure, replace with a genuine Komatsu coolant temperature sensor (Part #6754-81-6210 or equivalent). Clean all connector pins with electrical contact cleaner and apply dielectric grease to prevent future corrosion. For used machines, consider replacing the entire sensor-to-ECM harness section if insulation shows cracking or wear.

Step 5: Clear Code and Verify After repairs, clear the fault code using diagnostic software and run the engine through a complete heat cycle. Monitor for code recurrence and verify proper temperature gauge operation.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Komatsu PC800SE-7 service manual and consider professional assistance from certified Komatsu technicians for complex electrical diagnostics or if you're unfamiliar with high-voltage systems.