What is Komatsu PC200-10 Fault Code DWA2KA?

Fault Code DWA2KA indicates a malfunction in the hydraulic oil temperature sensor circuit or an abnormal hydraulic oil temperature reading in the Komatsu PC200-10 excavator. This diagnostic trouble code (DTC) is triggered when the machine's Electronic Control Module (ECM) detects that the hydraulic oil temperature sensor is reporting values outside the normal operating range, or when there's an electrical fault within the sensor circuit itself.

This code is critical for the PC200-10's performance because hydraulic oil temperature directly affects system viscosity, component lubrication, and seal integrity. The Komatsu KOMTRAX monitoring system uses this sensor data to prevent overheating damage to pumps, motors, and control valves. When this fault is active, the machine may enter a protective derate mode to prevent catastrophic hydraulic system failure. For used excavators, this code often signals age-related sensor degradation or wiring harness issues common in machines with 5,000+ operating hours.

Common Symptoms

• Warning light illumination on the instrument cluster, specifically the hydraulic system temperature indicator or general malfunction lamp
• Reduced hydraulic performance including slower cycle times, weaker digging force, or sluggish swing speed as the ECM limits pump output
• Audible alarm from the cab monitoring system when the fault becomes active
• Erratic temperature gauge readings that fluctuate rapidly or display unrealistic values (extremely high or low)
• Intermittent code activation that appears and disappears, especially during cold starts or after extended operation

Potential Causes

For the Komatsu PC200-10, especially in used machines, DWA2KA typically results from:

• Faulty hydraulic oil temperature sensor due to internal element failure, common after 6,000-8,000 operating hours
• Corroded or damaged wiring connectors at the sensor location near the hydraulic tank, exposed to moisture and debris
• Harness chafing or breaks along the wiring route from the sensor to the ECM, particularly at known rub points near the swing bearing area
• Contaminated hydraulic oil with metal particles causing sensor tip fouling or coating
• Poor electrical ground connection at the sensor mounting point due to rust or paint buildup
• ECM internal fault (less common) where the temperature monitoring circuit has failed

How to Troubleshoot and Fix Code DWA2KA

Step 1: Retrieve and Document the Fault Connect a Komatsu diagnostic laptop running genuine diagnostic software or compatible scan tool to the machine's diagnostic port. Record the active and stored fault codes, freeze frame data, and current hydraulic oil temperature reading. This baseline data is essential for used excavators that may have multiple intermittent issues.

Step 2: Inspect the Sensor and Connections Locate the hydraulic oil temperature sensor mounted on the hydraulic tank (typically on the left side near the return filter). Visually inspect the electrical connector for corrosion, bent pins, or oil contamination—common issues in older PC200-10 machines. Check the sensor mounting for looseness or leaking hydraulic oil, which can damage the sensor element.

Step 3: Perform Electrical Tests Disconnect the sensor wiring harness connector. Using a digital multimeter, measure the sensor's resistance across its terminals. A functioning sensor typically reads 200-300 ohms at room temperature (consult the PC200-10 service manual for exact specifications). Also check for continuity in the wiring harness from the sensor connector back to the ECM—any reading above 5 ohms indicates wire damage.

Step 4: Check for Harness Damage On used excavators, physically trace the sensor wiring harness along its entire route. Pay special attention to areas where the harness passes near moving components or sharp edges. Look for insulation wear, exposed wires, or previous repair attempts using electrical tape. Replace any compromised sections with proper gauge wire and weatherproof connectors.

Step 5: Test and Replace Components If the sensor fails resistance testing or shows physical damage, replace it with a genuine Komatsu temperature sensor (part number specific to PC200-10). Before installation, clean the mounting threads and apply appropriate thread sealant. If the sensor tests correctly, check the ECM connector pins for corrosion and verify proper voltage supply (typically 5V reference) from the ECM to the sensor.

Step 6: Clear Codes and Verify Repair After repairs, clear the fault codes using diagnostic software and operate the machine through a complete work cycle. Monitor the hydraulic oil temperature reading in real-time to ensure it displays normal values (typically 40-80°C during operation). For used machines, perform this verification test for at least 30 minutes under load to confirm the intermittent fault doesn't return.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Komatsu PC200-10 service manual for exact specifications, torque values, and safety procedures. If you're unfamiliar with electrical diagnostics or hydraulic systems, consult a certified Komatsu technician to prevent equipment damage or personal injury.