Komatsu PC210-8M0 Fault Code DHSAMA: Complete Diagnostic Guide

What is Komatsu PC210-8M0 Fault Code DHSAMA?

Fault Code DHSAMA indicates a communication error between the hydraulic system controller and the main Engine Control Module (ECM) on the Komatsu PC210-8M0 excavator. This code specifically relates to a breakdown in the CAN bus network that coordinates signals between the hydraulic pump controller and engine management system.

This fault is critical because the PC210-8M0 relies on continuous data exchange between these systems to optimize fuel efficiency, manage hydraulic flow rates, and prevent engine overload during heavy operations. When communication fails, the machine typically enters a derate mode to protect components, severely limiting productivity on job sites.

Common Symptoms

When DHSAMA is active, operators typically experience:

• Automatic engine power reduction (derate mode), limiting the machine to 70-80% of normal output
• Illuminated warning lights on the monitor panel, specifically the hydraulic system alert
• Sluggish or unresponsive hydraulic functions, particularly during combined operations like swinging while digging
• Intermittent loss of auxiliary hydraulic power to attachments like breakers or grapples
• Engine stalling or rough idle when hydraulic load is applied suddenly

Potential Causes

The most common technical causes for DHSAMA on used PC210-8M0 excavators include:

• CAN bus wiring harness damage near the swing bearing area where cables experience constant flexing and abrasion
• Corroded or moisture-contaminated connectors at the hydraulic controller module (often located behind the cab)
• Failed hydraulic pump solenoid driver circuit within the controller, common after 6,000+ operating hours
• ECM software version mismatch after controller replacements using non-OEM or refurbished parts
• Loose or damaged ground connections at the chassis grounding points near the battery box
• Failing CAN bus termination resistors (120-ohm resistors) causing signal reflection issues

How to Troubleshoot and Fix Code DHSAMA

Step 1: Visual Harness Inspection Physically inspect the main wiring harness between the ECM (located under the operator's seat) and the hydraulic controller. Focus on areas where the harness passes through the swing bearing and along the boom base—these are known wear points on used machines. Look for abraded insulation, pinched wires, or oil-soaked connectors.

Step 2: Connector and Ground Testing Disconnect the hydraulic controller connector (typically a 24-pin gray connector). Inspect for corrosion, bent pins, or moisture. Using a multimeter, verify continuity on the CAN-High and CAN-Low wires (usually yellow and green). Check resistance between CAN-High and CAN-Low; it should read approximately 60 ohms with controllers disconnected (indicating proper termination).

Step 3: Diagnostic Software Analysis Connect Komatsu KOMTRAX diagnostic software or an aftermarket tool compatible with Komatsu CAN protocols. Monitor real-time communication status between the ECM and hydraulic controller. Check for intermittent dropouts. Verify both controllers are running compatible firmware versions—mismatched software is common in used machines with replacement parts.

Step 4: Component-Level Testing If wiring checks pass, test the hydraulic pump solenoid outputs using the diagnostic software's actuator tests. Measure voltage at the solenoid connectors during activation (should be 12V±0.5V). On high-hour used excavators, internal controller failures are common; consider testing a known-good controller before purchasing replacements.

Important for Used Equipment: Before replacing expensive controllers ($800-2,500), thoroughly clean all ground points with a wire brush and apply dielectric grease. Approximately 40% of DHSAMA codes on used machines resolve through harness repair and connector servicing rather than component replacement.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu service manual for your specific serial number and consider professional diagnosis for complex electrical issues. Improper repairs can void warranties or cause additional system damage.