Komatsu PC210LC-8M0 Fault Code DHSAMA: Technical Guide

What is Komatsu PC210LC-8M0 Fault Code DHSAMA?

Fault Code DHSAMA indicates a communication error or data mismatch between the machine's main controller (EMMS - Equipment Management Monitoring System) and the hydraulic system control modules. This code specifically relates to the Controller Area Network (CAN) bus communication failure affecting the integrated control of the hydraulic and engine systems.

In the PC210LC-8M0, the EMMS continuously monitors and coordinates data between the engine ECM (Engine Control Module), hydraulic pump controller, and monitoring display. When communication packets are lost, corrupted, or delayed beyond acceptable thresholds, the system generates DHSAMA to protect machine integrity. This is critical because the PC210LC-8M0 relies on synchronized communication for fuel efficiency optimization, power mode selection, and hydraulic demand management. Communication failures can compromise machine performance and lead to unexpected operational behavior.

Common Symptoms

When fault code DHSAMA is active, operators typically experience:

• Intermittent or complete loss of monitor display information (engine RPM, hydraulic temperature readings disappear)
• Reduced machine performance with hydraulics responding sluggishly or inconsistently
• Power mode selection failure – inability to switch between work modes (PWR, STD, ECO)
• Amber or red warning lights illuminated on the dashboard with potential audible alarms
• Engine derating in severe cases, limiting RPM to protect the system from unsynchronized operation

Potential Causes

The most common technical causes for DHSAMA in used PC210LC-8M0 excavators include:

• Corroded or loose CAN bus connectors at the main wiring harness junction (common wear point behind the cab)
• Damaged CAN bus wiring from harness chafing against the swing bearing or boom cylinder mounting points
• Failed EMMS controller or corrupted firmware, particularly in machines with 8,000+ operating hours
• Voltage irregularities from aging batteries or failing alternators causing communication instability
• Water intrusion into sealed connector housings due to deteriorated grommets or damaged harness conduit
• Incompatible or outdated software versions between controllers after previous repair work

How to Troubleshoot and Fix Code DHSAMA

Step 1: Connect Komatsu diagnostic software (KOMTRAX Plus or dealer-level diagnostics) to read active and historical communication errors. Check for multiple simultaneous codes indicating widespread electrical issues versus isolated controller problems.

Step 2: Perform a thorough visual inspection of the main wiring harness, focusing on the CAN bus lines (typically twisted-pair orange/green wires). Check behind the operator cab, along the swing post, and near hydraulic valve banks for abrasion, cuts, or pinch points.

Step 3: Use a digital multimeter to verify CAN bus resistance. Measure between CAN-H and CAN-L terminals at the EMMS connector—should read approximately 60 ohms with all controllers connected. Readings significantly higher suggest open circuits; lower readings indicate short circuits.

Step 4: Inspect all controller connectors for corrosion, bent pins, or moisture. For used excavators, connector deterioration is extremely common. Clean with electrical contact cleaner and apply dielectric grease before reconnection.

Step 5: Check battery voltage under load—should maintain above 12.8V during cranking. Low voltage causes CAN communication instability. Test alternator output (should be 13.8-14.4V at operating RPM).

Step 6: If all physical checks pass, perform an EMMS reset through diagnostic software. If the code persists, suspect internal controller failure requiring replacement or reprogramming at a Komatsu dealer.

For used excavators, always prioritize inspecting harness wear patterns and connector conditions before replacing expensive electronic modules.

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Disclaimer: This guide provides general technical information. Always consult qualified Komatsu technicians and refer to official service manuals for your specific machine serial number before performing repairs. Improper diagnosis may cause further damage or safety hazards.