Komatsu PC210LC-10 Fault Code DHSAMA: Complete Diagnostic Guide

What is Komatsu PC210LC-10 Fault Code DHSAMA?

Fault Code DHSAMA indicates a Hydraulic System Abnormality related to the Main Pump Displacement Control System on the Komatsu PC210LC-10 excavator. This code specifically points to a communication or performance issue between the Engine Control Module (ECM) and the hydraulic pump control solenoid, affecting the machine's ability to properly regulate pump flow and pressure.

This fault is critical for the PC210LC-10's performance because the main pump displacement control directly governs how efficiently hydraulic power is distributed to all work functions. When this system malfunctions, the excavator cannot optimize fuel consumption or hydraulic responsiveness, leading to reduced productivity and potential component damage. The Komatsu KOMTRAX system logs this code when sensor data falls outside programmed parameters or when electrical signals from the displacement control valve are inconsistent.

Common Symptoms

When Code DHSAMA is active on your PC210LC-10, operators typically experience:

• Reduced hydraulic power across all functions (boom, arm, bucket, and swing operations feel sluggish)
• Amber hydraulic warning light illuminated on the monitor panel with potential audible alarm
• Engine auto-derating where RPMs are limited to protect the drivetrain from mismatched loads
• Inconsistent cycle times during digging or lifting operations, with noticeable hesitation
• Increased fuel consumption due to inefficient pump displacement matching

Potential Causes

The most common technical failures triggering DHSAMA on used PC210LC-10 excavators include:

• Failed or contaminated pump control solenoid valve (Komatsu part typically located on the main pump body)
• Damaged wiring harness between the ECM and solenoid, particularly at flex points near the turntable bearing where cables experience constant rotation stress
• Corroded or loose electrical connectors at the solenoid plug (common in machines with 5,000+ operating hours)
• Degraded pressure sensors within the hydraulic system providing incorrect feedback to the ECM
• ECM software glitches or internal ECM failure (less common but documented in early production units)
• Contaminated hydraulic oil affecting solenoid operation and sensor accuracy

How to Troubleshoot and Fix Code DHSAMA

Step 1: Connect Diagnostic Software Use Komatsu KTEC diagnostic software or a compatible diagnostic tool to read live data from the ECM. Check real-time voltage readings to the pump displacement solenoid (should range between 0-12V depending on load demand). Compare commanded displacement versus actual displacement percentages.

Step 2: Inspect Electrical Connections Power down the machine and physically inspect the solenoid connector on the main pump. Look for green corrosion, bent pins, or moisture intrusion—extremely common on used excavators. Check the wiring harness from the ECM (located in the cab floor area) following the routing through the center joint where abrasion frequently occurs.

Step 3: Test Solenoid Resistance Disconnect the solenoid and use a digital multimeter to measure resistance across the solenoid terminals. Specification is typically 10-15 ohms at room temperature (confirm with service manual). If readings are infinite or below 5 ohms, replace the solenoid.

Step 4: Check Hydraulic Oil Quality Sample the hydraulic tank and inspect for contamination, water content, or incorrect viscosity. Degraded oil affects solenoid valve operation. On used excavators, neglected maintenance often causes valve sticking.

Step 5: Perform Pressure Sensor Verification Test the main pump pressure sensor output voltage (typically 0.5-4.5V range). Use the diagnostic software to command pump displacement changes while monitoring sensor response for erratic behavior.

For used excavators specifically, always inspect harness routing for previous repair attempts, aftermarket splices, or rubbed-through insulation before replacing expensive components like the ECM or pump assembly.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu PC210LC-10 service manual and consider professional diagnosis for complex hydraulic-electronic systems. Improper repairs may void warranties or cause safety hazards.