What is Komatsu PC210-8 Fault Code DXE6KA?

Fault code DXE6KA on the Komatsu PC210-8 excavator indicates a communication error or data transmission failure between the Engine Controller (ECM) and the Hydraulic Control Module (HMC). This code specifically flags an abnormal signal or loss of CAN (Controller Area Network) bus communication between these two critical control systems.

The PC210-8 relies on continuous data exchange between the ECM and HMC to optimize engine performance, hydraulic flow, and fuel efficiency through Komatsu's CLSS (Closed-Center Load Sensing System). When this communication link fails, the excavator cannot properly coordinate engine output with hydraulic demand, compromising both performance and fuel economy. For used machines with higher operating hours, this code often points to degraded wiring harnesses or corroded connectors rather than controller failures.

Common Symptoms

When fault code DXE6KA is active on your PC210-8, you may experience:

• Warning light illumination on the monitor panel with reduced engine power or hydraulic responsiveness
• Erratic hydraulic function where boom, arm, or swing movements become sluggish or uncoordinated
• Engine operating in derate mode, limiting RPM to protect systems during communication loss
• Intermittent loss of diagnostic display information on the monitor screen
• Simultaneous activation of multiple warning indicators due to communication breakdown

Potential Causes

The most common technical causes for DXE6KA on used PC210-8 excavators include:

• Damaged or corroded CAN bus wiring harness between ECM and HMC, especially at flex points near the engine mount or along the chassis where cable routing experiences vibration
• Loose or oxidized connector terminals at the ECM or HMC plug connections (18-pin and 24-pin connectors)
• Failed terminating resistor on the CAN network (120-ohm resistor deterioration)
• ECM or HMC controller internal fault (less common but possible after electrical surges or water intrusion)
• Poor ground connections at controller mounting points causing signal interference
• Aftermarket radio or accessory installations creating electrical noise on the CAN network

How to Troubleshoot and Fix Code DXE6KA

Step 1: Visual Harness Inspection Begin by physically inspecting the CAN bus wiring harness running from the engine compartment ECM to the cab-mounted HMC. Look for rubbed insulation, especially where harnesses pass through metal grommets or contact the chassis. On used excavators with 5,000+ hours, check for oil contamination that degrades wire insulation.

Step 2: Connector and Ground Testing Disconnect the main ECM connector (located on the left side of the engine) and HMC connector (behind the operator's seat). Inspect pins for corrosion, bent contacts, or moisture. Clean with electrical contact cleaner and apply dielectric grease. Using a digital multimeter, verify ground continuity (should read less than 1 ohm resistance) at controller mounting bolts.

Step 3: CAN Bus Voltage and Resistance Check With the key in the ON position (engine off), measure voltage between CAN-High and CAN-Low wires at the ECM connector (typically pins 14 and 15). You should read approximately 2.5V differential. With the key off and both controllers disconnected, measure resistance across CAN-High to CAN-Low—you should find approximately 60 ohms (two 120-ohm terminating resistors in parallel).

Step 4: Diagnostic Software Verification Connect Komatsu KOMTRAX or compatible diagnostic software to verify real-time communication status. Monitor for intermittent dropouts while wiggling harnesses. If communication restores during manipulation, harness replacement is necessary.

Step 5: Component Replacement Priority For used machines, replace components in this order: harness repair/replacement first, then connectors, then terminating resistors, and finally controllers (only if all other checks pass). Controllers rarely fail without associated physical damage or water intrusion evidence.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu PC210-8 service manual and consider professional diagnostic services for complex electrical issues. Improper repairs may cause additional system damage or safety hazards.