Komatsu PC210-8 Fault Code E-17: Complete Diagnostic Guide

What is Komatsu PC210-8 Fault Code E-17?

Fault Code E-17 on the Komatsu PC210-8 indicates a hydraulic oil temperature sensor circuit malfunction or abnormal temperature reading detected by the machine's electronic control system. This code specifically relates to the hydraulic oil temperature sensor circuit, which continuously monitors the temperature of the hydraulic fluid to prevent overheating and protect critical hydraulic components.

The hydraulic temperature monitoring system is essential for the PC210-8's performance because excessive heat degrades hydraulic oil viscosity, reduces system efficiency, and can cause catastrophic damage to hydraulic pumps, motors, and control valves. The ECM (Engine Control Module) uses this sensor data to trigger cooling responses and warn operators before damage occurs.

Common Symptoms

When Code E-17 is active on your Komatsu PC210-8, operators typically experience:

• Warning light illumination on the instrument panel, specifically the hydraulic temperature warning indicator
• Reduced hydraulic performance or automatic derate of hydraulic system output to prevent damage
• Erratic temperature gauge readings that fluctuate abnormally or show maximum temperature immediately after startup
• Slow or sluggish hydraulic response, particularly during high-demand operations like digging or lifting
• Intermittent code triggering that clears and reappears, especially on used machines with aging wiring harnesses

Potential Causes

The most common technical causes for E-17 on used PC210-8 excavators include:

• Failed hydraulic oil temperature sensor due to internal component degradation (common after 5,000+ hours)
• Damaged or corroded wiring harness connections at the sensor plug, especially where the harness routes near the hydraulic tank
• Chafed wiring at known rub points along the main boom or swing bearing area where harness movement causes insulation wear
• ECM power supply issues affecting the sensor's 5-volt reference signal
• Contaminated hydraulic oil causing actual overheating that triggers legitimate sensor readings
• Loose or corroded ground connections in the hydraulic monitoring circuit

How to Troubleshoot and Fix Code E-17

Step 1: Visual Inspection Begin by locating the hydraulic oil temperature sensor (typically mounted on the hydraulic tank or main control valve). Inspect the sensor connector for corrosion, bent pins, or oil contamination. On used excavators, check the entire wiring harness from the sensor to the ECM for signs of chafing, particularly where it passes through bulkheads or near moving components.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor and measure the resistance across the sensor terminals. For the PC210-8, the sensor should typically read 200-300 ohms at room temperature (refer to your service manual for exact specifications). Next, check for continuity in the wiring harness from the sensor connector to the ECM. Test the 5-volt reference signal from the ECM at the sensor connector with the ignition on.

Step 3: Sensor and Circuit Verification If resistance values are out of specification or the wiring shows damage, replace the faulty component. For used machines, always apply dielectric grease to connector pins before reassembly to prevent future corrosion. Clear the code using Komatsu diagnostic software (KOMTRAX) or a compatible scan tool and monitor for recurrence. If the code returns immediately, suspect ECM issues or verify actual hydraulic temperature with an infrared thermometer to rule out genuine overheating.

Disclaimer: This guide provides general troubleshooting information. Always consult your Komatsu service manual and consider professional diagnostic assistance for complex electrical issues or if you're unfamiliar with hydraulic systems.