What is Komatsu PC110-8M0 Fault Code DWK0KB?

Fault Code DWK0KB indicates a communication error or data inconsistency within the Komatsu PC110-8M0's electronic control system, specifically affecting the machine monitoring system (MMS) and its ability to properly communicate with the engine controller (ECM). This code typically signals a breakdown in the CAN bus communication network that links various electronic modules throughout the excavator.

In the PC110-8M0 model, this fault directly impacts the machine's ability to relay critical operational data between the engine control module, hydraulic controller, and the instrument cluster. When this communication pathway is compromised, the excavator's integrated systems cannot function cohesively, potentially leading to reduced performance, safety concerns, and diagnostic difficulties. This is particularly critical in this compact excavator model because the integrated control architecture relies on constant data exchange to optimize fuel efficiency, hydraulic responsiveness, and emission controls.

Common Symptoms

When DWK0KB is active on your Komatsu PC110-8M0, operators typically experience:

• Warning lights illuminated on the instrument panel, specifically the engine malfunction lamp and/or system check indicator
• Intermittent or complete loss of digital display readings (RPM, fuel level, operating hours, temperature gauges)
• Erratic hydraulic performance or engine RPM fluctuations due to incomplete sensor data reaching controllers
• Engine derating or failure to achieve full power output as a protective measure
• Inability to access fault codes or perform diagnostics through the standard monitor panel

Potential Causes

The most common technical reasons for DWK0KB appearing on used PC110-8M0 excavators include:

• CAN bus wiring harness damage from vibration, rubbing against frame components, or rodent intrusion—particularly at harness routing points near the swing bearing and along the boom
• Corroded or loose connector pins at the ECM connector (typically located under the operator cab) or MMS junction box
• Failed or failing engine controller (ECM) due to moisture intrusion, a known vulnerability in machines with cab leaks or improper storage
• Voltage supply issues from weakened batteries, failing alternators, or poor ground connections at chassis ground points
• Software corruption in either the ECM or monitoring system from power interruptions during previous service work

How to Troubleshoot and Fix Code DWK0KB

Step 1: Visual Inspection of Harness and Connectors Begin by thoroughly inspecting the main wiring harness routing from the ECM to the instrument cluster. On used excavators, check specifically where harnesses pass through the swing bearing area and along the right-hand chassis rail—these are common rub points. Look for abraded insulation, pinched wires, or signs of previous repairs. Examine all CAN bus connectors for corrosion, bent pins, or contamination with dirt and moisture.

Step 2: Verify Power Supply and Ground Connections Using a digital multimeter, verify battery voltage (should read 12.4V minimum at rest, 13.8-14.4V when running). Check the ECM power supply at connector pins (consult service manual for specific pin locations) and ensure clean, tight connections at both the positive battery terminal and all chassis ground points, especially the main engine ground strap.

Step 3: CAN Bus Communication Testing With Komatsu diagnostic software (KOMTRAX Plus or dealer-level KTSS) and an appropriate diagnostic interface, monitor live CAN bus communication status. Check for voltage levels on CAN-High and CAN-Low wires (should read approximately 2.5V at rest, oscillating between 1.5-3.5V during communication). Resistance between CAN-High and CAN-Low should measure approximately 60 ohms with all modules connected.

Step 4: Component Isolation If communication remains disrupted, systematically disconnect non-critical modules (starting with auxiliary controllers) to isolate a potentially failed component creating bus interference. For used excavators with extended hours, the instrument cluster connector is particularly prone to internal failures from vibration fatigue.

Step 5: ECM and Software Verification If all wiring proves intact, the ECM firmware may require updating or the module itself may need replacement. Consult with a Komatsu dealer to verify the latest software version and whether any technical bulletins address communication issues for your machine's serial number range.

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Disclaimer: This guide provides general troubleshooting information for educational purposes. Always consult the official Komatsu service manual for your specific machine serial number and seek professional diagnostic assistance when working with electronic control systems. Improper repairs may cause additional damage or safety hazards.