What is Komatsu PC210-10 Fault Code DHSBMA?

Fault Code DHSBMA on the Komatsu PC210-10 excavator indicates a communication error or malfunction within the hydraulic system's electronic control network, specifically related to the main pump delivery system or pump control valve signals. This code typically appears when the machine's controller (ECM) detects abnormal data transmission between hydraulic system sensors and the pump control module.

The PC210-10 utilizes Komatsu's advanced CLSS (Closed-Center Load Sensing System), which relies on continuous electronic communication to optimize hydraulic flow and fuel efficiency. When fault code DHSBMA triggers, it signals that critical data from pressure sensors, solenoid valves, or the pump displacement controller isn't reaching the ECM properly. This directly impacts machine performance because the system cannot accurately adjust pump output to match operator demand, potentially causing inefficient operation or reduced hydraulic power.

Common Symptoms

• Hydraulic system derate or noticeably reduced boom/arm/bucket speed despite full throttle
• Monitor display warning showing hydraulic system error or "CHECK" light illumination on the instrument cluster
• Intermittent loss of hydraulic power during operation, especially when performing combined functions
• Erratic engine RPM fluctuation as the ECM attempts to compensate for unclear hydraulic load signals
• Increased fuel consumption due to the pump running at higher displacement than necessary when communication fails

Potential Causes

The most common technical causes for DHSBMA on used PC210-10 excavators include:

• Corroded or damaged connector pins on the pump control solenoid harness (frequently exposed to hydraulic fluid contamination near the main pump assembly)
• Worn or failed pressure sensor in the main control valve block, particularly the delivery pressure sensor which deteriorates over 5,000+ operating hours
• Wiring harness chafing at known rub points between the pump and ECM, especially where the harness routes near the swing bearing or undercarriage
• Voltage drop issues caused by poor grounding connections on aged machines, particularly the chassis ground near the hydraulic tank
• ECM software glitches or internal controller faults (less common but possible on machines with 10,000+ hours)

How to Troubleshoot and Fix Code DHSBMA

Step 1: Connect Diagnostic Software Use Komatsu PLUS+1 or Komatsu Diagnostics (KDI) software with the 6-pin diagnostic connector under the operator's cab. Read active and stored codes, and check real-time data for pump pressure sensor values. Look for erratic readings or "no signal" indicators that pinpoint the faulty circuit.

Step 2: Inspect Wiring and Connectors Physically trace the pump control harness from the ECM to the main pump solenoid valves. On used excavators, pay special attention to connector C-347 (pump solenoid connector) and C-221 (pressure sensor connector). Check for:

• Green corrosion on pins (clean with electrical contact cleaner)
• Bent or pushed-back connector pins
• Harness rubbing damage near mounting brackets

Use a multimeter to verify continuity: resistance should be less than 5 ohms between ECM connector and pump solenoid pins.

Step 3: Test Sensors and Voltage Supply Measure supply voltage at the delivery pressure sensor connector with ignition ON (should read 4.8-5.2V). Check sensor output signal voltage while manually creating hydraulic pressure (should vary from 0.5V to 4.5V proportionally). Replace sensors showing fixed voltage or readings outside specifications.

Step 4: Check Ground Circuits Verify chassis ground G-104 (located on left side of hydraulic tank mounting bracket) shows less than 0.1 ohms resistance to battery negative. Clean and retighten if necessary—this is a critical issue on machines operating in wet or corrosive environments.

Step 5: Clear Code and Test After repairs, clear fault codes using diagnostic software, operate the machine through full hydraulic functions for 20 minutes, and re-scan. If DHSBMA returns, suspect ECM internal fault or software requiring dealer-level programming.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Komatsu PC210-10 service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs may cause equipment damage or safety hazards.