Komatsu PC800-7 Fault Code DA2SKA: Complete Diagnostic Guide

What is Komatsu PC800-7 Fault Code DA2SKA?

Fault Code DA2SKA indicates a communication error or data link failure between the engine controller (ECM) and the machine controller (MCU) on the Komatsu PC800-7 excavator. This code specifically relates to the CAN (Controller Area Network) bus system that enables critical real-time communication between the machine's electronic control units.

The DA2SKA code is part of Komatsu's proprietary diagnostic system and signals that the ECM cannot properly exchange operational data with the MCU. This communication breakdown is critical because it affects engine performance parameters, hydraulic system coordination, and safety monitoring functions. On the PC800-7, this fault can trigger protective modes that limit machine capability to prevent potential damage.

Common Symptoms

When fault code DA2SKA is active, operators typically experience:

• Engine derate or power limitation – the machine may enter a reduced power mode to protect systems
• Intermittent or complete loss of monitor display data – gauge cluster may show incorrect readings or go blank
• Warning lights illuminated on the dashboard, particularly the engine and system malfunction indicators
• Erratic hydraulic response – inconsistent boom, arm, or bucket movements due to communication delays
• Engine may fail to start or shut down unexpectedly in severe cases

Potential Causes

The most common technical causes for DA2SKA on used PC800-7 excavators include:

• CAN bus wiring harness damage – particularly at flex points near the engine mount or cab pivot where cables experience repeated bending and vibration
• Corroded or loose connector pins at the ECM or MCU connection points, especially on machines with high operating hours in wet environments
• Failed termination resistors on the CAN network causing signal reflection and data corruption
• ECM or MCU internal failure – less common but possible on high-hour machines
• Voltage supply issues – low battery voltage or poor grounding affecting controller operation
• Water intrusion into controller housings or harness connectors

How to Troubleshoot and Fix Code DA2SKA

Step 1: Visual Inspection Begin with a thorough physical inspection of all wiring harnesses between the engine compartment and cab. On used excavators, check for harness rub points, particularly where cables route through the swing bearing area. Look for abraded insulation, pinched wires, or signs of previous repairs. Inspect all connector plugs at both the ECM (typically mounted on the engine) and MCU (usually behind the operator's seat) for corrosion, bent pins, or moisture.

Step 2: Electrical Testing Using a digital multimeter, verify battery voltage is above 24V (for 24V systems). Check ground connections at both controllers for resistance below 1 ohm. With Komatsu diagnostic software (KOMTRAX Plus or equivalent), monitor live CAN bus communication. Check CAN-High and CAN-Low voltage levels – they should read approximately 2.5V at rest, with CAN-High rising to 3.5V and CAN-Low dropping to 1.5V during communication.

Step 3: Component Testing Measure termination resistor values at both ends of the CAN network – each should read 120 ohms, with a combined parallel resistance of 60 ohms across CAN-High and CAN-Low. If readings are incorrect, locate and replace failed resistors. For used machines, consider replacing all connector seals even if they appear intact, as age-related deterioration allows moisture ingress.

Step 4: Controller Verification If wiring and connections test properly, the fault likely resides in a controller. Swap controllers with known-good units if available, or send for professional bench testing. Before replacing expensive ECM or MCU units on used equipment, verify the issue isn't intermittent by monitoring the fault during operation under various loads.

Disclaimer: This guide provides general diagnostic information. Always consult the official Komatsu service manual for your specific machine serial number and consider professional diagnostic services for complex electrical issues.