Komatsu PC800-8R Fault Code E01D110KB: Complete Diagnostic Guide

What is Komatsu PC800-8R 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 the PC800-8R excavator series.

The CAN bus serves as the central nervous system for this excavator, allowing multiple electronic control units to communicate critical operational data. When this communication pathway fails or experiences interference, the ECM (Engine Control Module) cannot properly coordinate with hydraulic controllers, potentially affecting machine performance and safety systems. For the PC800-8R, a 78-ton class excavator with sophisticated hydraulic management, maintaining reliable ECU communication is essential for optimal fuel efficiency, hydraulic response, and emission control.

Common Symptoms

When Code E01D110KB is active, operators typically experience:

• Warning light illumination on the monitor panel, often accompanied by a specific error message display
• Reduced hydraulic response or sluggish boom/arm movements due to ECU coordination failure
• Engine derate mode activation, limiting RPM to protect the powertrain
• Intermittent loss of monitor functions, including gauge readings or backup camera display
• Difficulty starting or unexpected engine shutdown in severe cases

Potential Causes

The most common technical causes for this fault code in used PC800-8R excavators include:

• Corroded or damaged CAN bus connectors, particularly at harness junction points near the engine bay where moisture accumulation occurs
• Wiring harness chafing at known rub points along the right-side frame rail and near the swing bearing
• Failed termination resistors in the CAN network (typically 120-ohm resistors at network endpoints)
• ECU power supply issues, including poor ground connections or voltage fluctuations
• Controller module failure in either the engine ECM or hydraulic ECU due to age-related component degradation
• Aftermarket accessory interference from improperly installed auxiliary equipment affecting the CAN network

How to Troubleshoot and Fix Code E01D110KB

Step 1: Visual Inspection and Connector Check

Begin with a thorough physical inspection of all CAN bus harness connectors. On used excavators, focus on the main harness routing from the engine ECM (located behind the operator cab) to the hydraulic controller (mounted near the hydraulic pump). Check for:

• Green corrosion on connector pins
• Damaged or bent terminals
• Moisture inside connector housings
• Harness wear at cable ties and frame contact points

Clean all connectors with electrical contact cleaner and apply dielectric grease before reconnecting.

Step 2: CAN Bus Electrical Testing

Using a digital multimeter, measure the CAN-High and CAN-Low resistance between the two signal wires at the ECM connector (typically pins 23 and 24). You should read approximately 60 ohms with the key off, indicating proper termination resistors. A reading of 120 ohms suggests one terminator has failed; infinite resistance indicates an open circuit in the network.

Check for voltage presence on CAN lines with key on, engine off—you should see approximately 2.5V on both lines. Significant deviation indicates a short to power or ground.

Step 3: Advanced Diagnostics with Komatsu KTEC Software

Connect Komatsu's KTEC diagnostic software (or compatible third-party tools like Jaltest) to access detailed fault data. Monitor live CAN bus traffic to identify which controller is failing to communicate. Check for:

• Message error counters in each ECU
• Bus-off conditions indicating a faulty controller
• Intermittent communication dropouts suggesting harness issues

For used excavators, perform a harness wiggle test while monitoring communication—flex suspect harness sections to reproduce intermittent faults.

Step 4: Component Replacement Protocol

If diagnostics point to a specific component, replace in this order:

1. Damaged harness sections or connectors (most common in used machines)
2. Termination resistors if resistance values are incorrect
3. The communicating ECU showing consistent errors

Always clear codes after repairs and perform a complete operational test cycle before returning the machine to service.

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Disclaimer: This guide provides general diagnostic information for experienced technicians. Always consult the official Komatsu service manual for your specific machine serial number and consider professional diagnostic services for complex electrical issues. Improper repairs to electronic systems can cause additional damage or safety hazards.