What is Komatsu PC360-7 Fault Code DA2SKQ?

Komatsu PC360-7 fault code DA2SKQ indicates a communication error between the engine controller (ECM) and the hydraulic pump control system, specifically related to the pump flow control solenoid circuit.

This diagnostic trouble code (DTC) appears when the Engine Control Module (ECM) detects an abnormal signal or loss of communication with the hydraulic pump flow control solenoid. On the PC360-7 equipped with the SAA6D114E-2 engine, this solenoid regulates hydraulic pump displacement based on engine load and operator demand. When communication fails, the machine's integrated control system cannot properly match hydraulic output to engine performance, potentially causing inefficient operation, reduced productivity, and increased fuel consumption. This code is particularly critical because the PC360-7 relies on precise coordination between engine management and hydraulic systems for optimal digging force and swing speed.

Common Symptoms

• Warning light illumination on the monitor panel, often accompanied by a wrench or engine icon
• Reduced hydraulic response or sluggish boom/arm/bucket movements, especially under heavy loads
• Engine derating where the machine limits maximum RPM to approximately 1,800 RPM to protect components
• Intermittent loss of hydraulic power during operation, with power returning after restarting
• Increased fuel consumption due to inefficient pump control and engine-hydraulic mismatch

Potential Causes

The most common causes of DA2SKQ on used PC360-7 excavators include:

• Corroded or damaged connectors at the pump flow control solenoid (located on the main hydraulic pump)
• Wiring harness chafing where the solenoid harness passes near the engine mounting brackets or hydraulic lines—a known wear point on machines with 5,000+ hours
• Failed pump flow control solenoid due to internal coil degradation or contamination from hydraulic fluid ingress
• Low voltage supply to the solenoid circuit caused by poor ground connections or battery/alternator issues
• ECM software glitches or corrupted calibration files, more common after previous repair attempts or unauthorized ECM replacements

How to Troubleshoot and Fix Code DA2SKQ

Step 1: Visual Inspection Begin with a thorough inspection of the pump flow control solenoid connector and associated wiring. On used excavators, check for oil contamination, corrosion on pins, and physical damage. Inspect the wiring harness routing between the ECM (located behind the operator cab) and the hydraulic pump, paying special attention to potential rub points near engine mounts and hydraulic hoses.

Step 2: Electrical Testing Using a digital multimeter, check the solenoid resistance. Disconnect the solenoid connector and measure resistance across the solenoid terminals—specifications typically range from 3-7 ohms at room temperature. Next, verify supply voltage at the connector with the ignition on (should read approximately 12-24V depending on system configuration). Check ground continuity between the solenoid ground wire and chassis ground (should read less than 1 ohm).

Step 3: Communication Verification Connect Komatsu diagnostic software (KOMTRAX or compatible scan tool) to read live data from the ECM. Monitor the solenoid command signal while operating hydraulic functions. If voltage commands change but symptoms persist, the solenoid itself is likely failed. If no command signal appears, suspect ECM internal issues or corrupted software.

Step 4: Component Replacement If testing confirms solenoid failure, replace with a genuine Komatsu pump flow control solenoid (part number specific to SAA6D114E-2 application). For used machines, always replace the connector pigtail simultaneously, as corrosion often recurs on old connectors. After replacement, clear codes using diagnostic software and perform a calibration cycle.

Critical Note for Used Excavators: Before replacing expensive components like the solenoid or ECM, thoroughly clean all connectors with electrical contact cleaner and apply dielectric grease. Many DA2SKQ codes on high-hour machines resolve through connector maintenance alone, saving hundreds in unnecessary parts costs.

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Disclaimer: This guide provides general troubleshooting information for the Komatsu PC360-7. Always consult the official Komatsu service manual for your specific machine serial number and seek assistance from certified Komatsu technicians for complex electrical diagnostics or hydraulic system repairs.