What is Komatsu PC210-8 Fault Code DWA2KA?

Fault Code DWA2KA on the Komatsu PC210-8 excavator indicates a communication error between the Engine Control Module (ECM) and the Machine Controller (MC), specifically related to CAN (Controller Area Network) bus communication failure. This diagnostic trouble code means the electronic control systems cannot properly exchange critical operational data, affecting the machine's ability to coordinate engine performance with hydraulic and operational functions.

This code is particularly critical for the PC210-8 because this model relies heavily on integrated electronic control systems to manage fuel efficiency, power output, and hydraulic response. When communication breaks down between the ECM and Machine Controller, the excavator may enter a protective derate mode to prevent potential damage, significantly impacting jobsite productivity.

Common Symptoms

• Warning lights: The check engine light or machine malfunction indicator illuminates on the dashboard, often accompanied by an audible alarm
• Power deration: The engine may automatically reduce power output to 70-80% capacity, limiting digging force and swing speed
• Erratic hydraulic response: Inconsistent or sluggish hydraulic functions due to disrupted communication between control systems
• Monitor display errors: The information display may show communication errors or fail to display certain operational parameters
• Intermittent starting issues: The machine may occasionally fail to start or experience delayed cranking due to control system handshake failures

Potential Causes

The most common technical causes for DWA2KA on used PC210-8 excavators include:

• CAN bus wiring damage: Harness abrasion at known rub points near the swing bearing or along the undercarriage, especially where cables pass through protective conduits
• Corroded or loose connectors: The 60-pin ECM connector or Machine Controller harness connectors developing corrosion from water intrusion, particularly common in machines operated in wet conditions
• Failed termination resistors: The 120-ohm termination resistors on the CAN network degrading or becoming disconnected, causing signal reflection and data corruption
• ECM or Machine Controller failure: Electronic module degradation from age, vibration, or voltage spikes in older machines
• Battery voltage irregularities: Low voltage (below 22V on a 24V system) or voltage drops during cranking affecting controller communication stability

How to Troubleshoot and Fix Code DWA2KA

Step 1: Verify CAN Bus Communication Integrity

Connect Komatsu KOMTRAX diagnostic software or compatible scan tool to retrieve active and stored codes. Check for additional communication-related codes that may pinpoint the affected circuit. Use a digital multimeter to measure CAN High and CAN Low voltage at the ECM connector (typically pins 15 and 16). You should see approximately 2.5V on each line at idle, with 1V differential during active communication.

Step 2: Inspect Wiring Harnesses and Connectors

Physically trace the main wiring harness from the ECM (located near the engine) to the Machine Controller (typically under the operator cab). Pay special attention to the swing bearing pass-through area where the harness transitions from the upper structure to the lower frame—this is a known wear point on used PC210-8 machines. Look for:

• Chafed or pinched wires with exposed copper
• Green corrosion on connector pins (indicates moisture intrusion)
• Loose or backed-out pins in the Deutsch-style connectors
• Cracked connector housings allowing water penetration

Step 3: Test Termination Resistors and Ground Circuits

Disconnect power and measure resistance between CAN High and CAN Low terminals at both the ECM and Machine Controller. You should read approximately 60 ohms (two 120-ohm resistors in parallel). If the reading is significantly higher (open circuit) or lower (short), locate and replace the faulty termination resistor. Also verify ground circuit integrity by checking resistance between the ECM ground and battery negative—it should be less than 0.5 ohms.

Step 4: Address Used Equipment-Specific Issues

For used excavators, thoroughly clean all connectors with electrical contact cleaner and apply dielectric grease to prevent future corrosion. Check battery voltage under load (should maintain above 22V during cranking). Inspect for aftermarket accessories or modifications that may have compromised the CAN network integrity. If harness damage is found, repair using proper CAN-rated twisted pair cable (not standard wire) and ensure proper shielding is maintained.

Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Komatsu service manual for your specific machine serial number and seek professional diagnostic assistance when dealing with complex electronic systems. Improper repairs to CAN bus systems can cause additional control module damage.