Komatsu PC850-8R Fault Code E01D110KB: Complete Diagnostic Guide

What is Komatsu PC850-8R Fault Code E01D110KB?

Fault Code E01D110KB indicates a communication error or abnormal signal detected in the machine's electronic control system, specifically related to the CAN (Controller Area Network) bus communication between the engine controller and hydraulic system ECU. This code is part of Komatsu's proprietary diagnostic system used in their Dash-8R series excavators.

The PC850-8R relies on continuous data exchange between multiple electronic control modules to optimize engine performance, hydraulic flow, and operational efficiency. When the ECM (Engine Control Module) cannot properly communicate with peripheral controllers, the system triggers E01D110KB to prevent potential damage from uncoordinated system operations. This fault is critical because it can lead to reduced machine performance, unexpected derating, or complete operational shutdown if left unresolved.

Common Symptoms

When fault code E01D110KB is active, operators typically experience:

• Warning light illumination on the monitor panel, often accompanied by an audible alarm
• Reduced engine power or hydraulic response, as the system enters a protective derate mode
• Intermittent loss of monitor display functions or erratic gauge readings
• Sluggish or unresponsive hydraulic controls, particularly during combined operations
• Engine may run rough or fail to reach full RPM under load conditions

Potential Causes

The most common technical causes for E01D110KB on used PC850-8R excavators include:

• Corroded or damaged CAN bus connectors, particularly at the main harness junction near the swing bearing (a known wear point on this model)
• Frayed or pinched wiring harness between the engine bay and cab, often caused by years of machine vibration
• Failed termination resistor in the CAN network (typically 120-ohm resistors at network endpoints)
• ECU power supply issues, including poor ground connections or voltage fluctuations
• Water intrusion into controller housings, common in machines with compromised seals
• Software version mismatch between controllers after component replacement or incomplete updates

How to Troubleshoot and Fix Code E01D110KB

Step 1: Initial Visual Inspection Begin by thoroughly inspecting all wiring harnesses along the CAN bus network. On used excavators, pay special attention to harness routing near the swing bearing, hydraulic pump area, and cab entry points where friction and flexing cause insulation breakdown. Check all connector pins for corrosion, bent terminals, or moisture intrusion.

Step 2: Electrical Testing Using a digital multimeter, verify CAN-High and CAN-Low voltage levels at multiple points in the network. With ignition on and engine off, you should measure approximately 2.5V on both lines (idle state). Check termination resistance by measuring between CAN-High and CAN-Low with all controllers disconnected—you should read approximately 60 ohms (two 120-ohm resistors in parallel). Any significant deviation indicates a wiring fault or missing terminator.

Step 3: Controller Communication Test Connect Komatsu KOMTRAX diagnostic software or compatible scan tool to access live data streams. Monitor communication status between all ECUs while wiggling harnesses to identify intermittent connections. Check for voltage drops at controller power supplies—the ECM should receive stable 24V with less than 0.5V drop under load.

Step 4: Component Replacement Protocol If testing reveals a faulty controller, ensure replacement units have matching software versions. For used machines, always clean and apply dielectric grease to all reconnected terminals. After repairs, clear codes and perform a complete operational test cycle before returning to service.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Komatsu service manual for your specific machine serial number and consider professional assistance for complex electrical diagnostics. Improper repairs may void warranties or create safety hazards.