Komatsu PC210-10 Fault Code E-36: Complete Diagnostic Guide

What is Komatsu PC210-10 Fault Code E-36?

Fault Code E-36 on the Komatsu PC210-10 indicates a malfunction in the swing motor pressure sensor circuit. This code specifically signals that the Electronic Control Module (ECM) has detected an abnormal voltage reading from the pressure sensor monitoring hydraulic pressure in the swing motor system.

The swing motor pressure sensor plays a critical role in the PC210-10's Hydraulic Management System (HMS). It continuously communicates pressure data to the ECM, which adjusts hydraulic flow and engine output to optimize swing performance while preventing system overload. When this sensor circuit fails, the machine may enter a protective derate mode to prevent damage to expensive hydraulic components, significantly reducing productivity on the job site.

Common Symptoms

When Code E-36 is active on your Komatsu PC210-10, operators typically experience:

• Warning light illumination on the monitor panel, often accompanied by an audible alarm
• Reduced swing speed or complete loss of swing function during operation
• Erratic swing performance with jerky or inconsistent rotation movements
• Engine power limitation as the ECM restricts output to protect the hydraulic system
• Intermittent fault that may appear and disappear, especially during temperature changes or machine vibration

Potential Causes

The E-36 code in used Komatsu PC210-10 excavators commonly stems from:

• Failed pressure sensor due to internal component degradation or contaminated hydraulic fluid
• Damaged wiring harness at known rub points near the swing bearing and center joint area
• Corroded or loose connector pins at the sensor plug, particularly on machines operating in wet or corrosive environments
• Short circuit or open circuit in the sensor signal wire between the sensor and ECM
• Contaminated hydraulic oil causing sensor membrane damage or internal valve issues
• ECM software glitches requiring calibration updates (less common but documented in early PC210-10 units)

How to Troubleshoot and Fix Code E-36

Step 1: Visual Inspection Begin by locating the swing motor pressure sensor mounted on the swing motor assembly. Inspect the connector for corrosion, moisture, or damaged pins—common issues in used excavators. Check the wiring harness routing from the sensor to the ECM, paying special attention to areas where the harness passes through the center joint and contacts metal surfaces. Look for abrasion, cuts, or pinched wires.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor connector and measure resistance across the sensor terminals. Compare readings to Komatsu specifications (typically 200-500 ohms at operating temperature). Test voltage supply from the ECM—you should see approximately 5 volts on the reference wire with ignition on. Check for continuity on the ground circuit and signal wire back to the ECM.

Step 3: Sensor and Harness Replacement If electrical values fall outside specifications, replace the pressure sensor with a genuine Komatsu part (part number 7861-93-1650 or equivalent). For used machinery, even if sensor readings are borderline acceptable, inspect the connector seal and replace if compromised. If wiring damage is found, repair using proper gauge wire and heat-shrink connectors, or replace the entire harness section to prevent future failures.

Step 4: System Verification After repairs, use Komatsu KOMTRAX diagnostic software or a compatible scan tool to clear the fault code and perform a pressure calibration test. Monitor live sensor data during swing operation to ensure pressure readings are stable and within the 0-35 MPa normal operating range. Test the machine under load to confirm swing function has fully recovered.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu PC210-10 service manual and consider professional diagnostic assistance for complex electrical issues or if you lack proper tools and training.