What is Komatsu PC360-7 Fault Code DA2SKA?

Fault Code DA2SKA indicates a communication error between the engine ECM (Electronic Control Module) and the machine controller on the Komatsu PC360-7 excavator. This diagnostic trouble code specifically points to a CAN (Controller Area Network) bus communication failure or data transmission interruption between critical control systems.

The Komatsu PC360-7 relies on constant communication between its SAA6D114E-2 engine ECM and the machine's main controller to coordinate hydraulic functions, engine performance, and emission controls. When this communication link fails, the excavator cannot properly synchronize these systems, potentially causing operational limitations or complete shutdown. This code is particularly critical because it affects the integrated control system that distinguishes modern excavators from older mechanical models.

Common Symptoms

• Warning lights: The machine controller warning lamp and engine check lamp illuminate simultaneously on the monitor panel
• Reduced engine power: The excavator may enter a derate mode or limp-home condition, limiting engine RPM to 1200-1400 RPM
• Erratic hydraulic response: Inconsistent or sluggish hydraulic movements due to improper coordination between engine output and hydraulic demand
• Intermittent shutdown: The machine may experience unexpected shutdowns, especially under load
• Monitor display errors: The information display may show incomplete data or error messages regarding system communication

Potential Causes

The most common technical causes for DA2SKA on used PC360-7 excavators include:

• CAN bus wiring harness damage: Frayed or broken wires in the main harness between the engine compartment and cab, particularly at known stress points near the swing bearing
• Corroded or loose connectors: The 9-pin or 12-pin CAN communication connectors often corrode in used machines exposed to moisture
• ECM power supply issues: Voltage fluctuations or poor ground connections at the engine ECM causing intermittent communication dropout
• Faulty termination resistors: The 120-ohm CAN bus termination resistors may fail on older excavators, disrupting signal integrity
• Controller module failure: Less common but possible—internal ECM or machine controller malfunction due to age or electrical surge damage

How to Troubleshoot and Fix Code DA2SKA

Step 1: Visual Inspection of Harness and Connectors Begin by inspecting the entire CAN bus wiring harness from the engine ECM (located right side of engine) to the machine controller (behind the operator's seat). On used PC360-7s, check for harness wear at the swing post area where cables pass through—this is a known friction point. Examine all connectors for bent pins, corrosion, or moisture intrusion.

Step 2: Test CAN Bus Continuity and Resistance Using a digital multimeter, disconnect both CAN bus connectors and measure resistance between CAN-High and CAN-Low terminals. You should read approximately 60 ohms (two 120-ohm termination resistors in parallel). If you read open circuit or significantly different values, locate and replace faulty termination resistors or repair broken wires.

Step 3: Check Power Supply and Grounds Verify that the engine ECM has stable power. Measure voltage at the ECM connector with the key in ON position—you should see 24V DC (±2V). Check ground connections at both the ECM and machine controller, cleaning and tightening as necessary. Corroded grounds are extremely common on used excavators.

Step 4: Advanced Diagnostics with Komatsu Software Connect Komatsu diagnostic software (KOMTRAX or PC Service Tool) to read live CAN bus data. Monitor communication packet loss and timing. If hardware tests pass but communication remains intermittent, the issue may be internal ECM or controller failure requiring replacement.

For used excavators specifically: Always inspect wiring for previous repair attempts or aftermarket modifications that may have compromised CAN bus shielding or proper termination.

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Disclaimer: This guide provides general troubleshooting steps for informational purposes. Complex electrical diagnostics should be performed by qualified Komatsu technicians with proper training and equipment. Always consult the official Komatsu PC360-7 service manual and follow safety protocols when working on heavy equipment.