What is Komatsu PC215-10MO Fault Code DWKOKY?

Fault Code DWKOKY on the Komatsu PC215-10MO indicates a communication error or data transmission failure within the machine's Controller Area Network (CAN) system, specifically affecting information exchange between the Engine Control Module (ECM) and the Machine Control Module (MCM).

This diagnostic trouble code signals that critical operational data is not being properly transmitted between control systems. The CAN bus network serves as the central nervous system for modern excavators, coordinating engine performance, hydraulic functions, and monitoring systems. When this communication breaks down, the PC215-10MO cannot optimize fuel delivery, hydraulic response, or emission controls effectively. For used excavators, this code often indicates age-related deterioration of wiring harnesses or connector corrosion rather than catastrophic component failure.

Common Symptoms

When fault code DWKOKY is active, operators typically experience:

• Engine warning light illuminated on the monitor panel, sometimes accompanied by a check engine indicator
• Intermittent loss of hydraulic power or sluggish response during combined operations (swing and boom movements)
• Engine derate mode activation, limiting RPM to approximately 1,500-1,800 to protect systems
• Monitor display showing incomplete or frozen operational data (fuel consumption, engine hours, temperature readings)
• Occasional engine stalling during idle or under heavy load conditions

Potential Causes

The most common technical reasons for DWKOKY appearing on used PC215-10MO excavators include:

• Corroded or damaged CAN bus connectors at the ECM or MCM connection points (especially the 38-pin main harness connector)
• Worn or frayed wiring harness due to rubbing against the engine block or frame near the fuel filter mounting area
• Faulty terminating resistors in the CAN network (120-ohm resistors that maintain signal integrity)
• ECM or MCM software corruption or outdated firmware versions
• Voltage irregularities caused by failing alternator or weak battery connections affecting data transmission
• Physical damage to control modules from water intrusion through deteriorated cab floor seals

How to Troubleshoot and Fix Code DWKOKY

Step 1: Visual Inspection Begin by thoroughly inspecting all wiring harnesses between the ECM (located behind the operator seat) and MCM (mounted near the hydraulic pump). Check for obvious damage, chafing, or connector corrosion. On used excavators, pay special attention to harness routing near heat sources and moving components.

Step 2: Connector Testing Disconnect the main CAN bus connectors at both control modules. Clean all pins with electrical contact cleaner and inspect for bent terminals or green corrosion. Use a digital multimeter to check continuity on the CAN-High and CAN-Low wires (typically yellow and green). Resistance between these wires should read approximately 60 ohms with both modules disconnected.

Step 3: Terminating Resistor Verification Verify that 120-ohm terminating resistors are present at both network endpoints. Measure resistance across CAN-High and CAN-Low at each module with harness disconnected; each should show 120 ohms.

Step 4: Voltage Supply Check With the ignition on, verify that both the ECM and MCM are receiving proper voltage (typically 24V DC). Check ground connections for resistance below 0.5 ohms.

Step 5: Software Diagnostics Connect Komatsu KOMTRAX diagnostic software or compatible scan tool to read detailed fault data and check for software updates. Clear codes and perform a static test to verify communication restoration.

Disclaimer: This guide provides general diagnostic procedures. Complex electrical issues on heavy equipment require professional evaluation. Always consult Komatsu-certified technicians and refer to the official PC215-10MO service manual for model-specific specifications before performing repairs.