What is Komatsu PC210LC-8 Fault Code E-24?

Fault Code E-24 on the Komatsu PC210LC-8 indicates a malfunction in the hydraulic pump solenoid valve circuit, specifically related to the main pump delivery pressure control system. This code triggers when the Electronic Control Module (ECM) detects an abnormal voltage or resistance in the solenoid valve circuit that regulates hydraulic pump displacement.

The PC210LC-8 uses sophisticated load-sensing hydraulic technology where the ECM continuously adjusts pump output based on operational demand. The pump solenoid valve modulates hydraulic flow by controlling the swash plate angle inside the variable displacement pump. When E-24 appears, the machine loses precise control over hydraulic delivery pressure, directly impacting digging force, swing speed, and overall fuel efficiency. For used excavators, this code often surfaces after 6,000+ operating hours when electrical connections deteriorate or solenoid internals begin failing.

Common Symptoms

When Code E-24 activates on your PC210LC-8, operators typically experience:

• Reduced hydraulic power across all functions, with noticeably slower boom and arm movements
• Intermittent or constant illumination of the engine malfunction warning light on the monitor panel
• Erratic pump response during combined operations (e.g., boom lift with swing activation)
• Abnormal engine load fluctuations or hunting at idle due to improper pump compensation
• Error code display on the Komtrax monitor or diagnostic screen showing "E-24 Pump Control Circuit"

Potential Causes

The most common technical failures triggering E-24 in used PC210LC-8 excavators include:

• Solenoid valve internal short or open circuit due to coil degradation (common after 8,000 hours)
• Damaged wiring harness at known rub points near the main pump mounting bracket or along the right-side frame rail
• Corroded or loose connector pins at the 6-pin pump solenoid connector (P106 connector designation)
• Failed pump solenoid valve caused by contaminated hydraulic fluid allowing metal particles into the spool chamber
• ECM power supply issues or poor grounding at the ECM mounting location behind the operator cab
• Voltage drop in the machine's main electrical system from aging batteries or corroded battery terminals

How to Troubleshoot and Fix Code E-24

Step 1: Perform Initial Visual Inspection Before diagnostics, inspect the pump solenoid connector (P106) located on the right side of the main hydraulic pump. On used machines, check for oil contamination, bent pins, or corrosion. Clean connectors with electrical contact cleaner and verify the harness has no visible abrasion where it routes past the pump mounting bolts.

Step 2: Test Solenoid Valve Resistance Disconnect the P106 connector and measure resistance across the solenoid terminals using a digital multimeter. Specification should read 3.5-4.5 ohms at 20°C (68°F). Readings below 2 ohms indicate a shorted coil; readings above 10 ohms suggest an open circuit or internal break. Replace the solenoid valve assembly if out of specification.

Step 3: Check Circuit Voltage and Wiring With ignition ON (engine not running), backprobe the harness side of P106 and verify battery voltage (12V nominal) is present on the power supply pin. Use the PC210LC-8 wiring diagram to trace circuit continuity back to ECM connector E2, pin 18. Check for voltage drops exceeding 0.5V, which indicate corroded connections or damaged wiring—common in used excavators operating in corrosive environments.

Step 4: Verify ECM Function and Ground Integrity Test the ECM ground circuit at terminal E1-22. Resistance to chassis ground should be less than 1 ohm. For used machines, remove the ECM mounting bolts and clean the grounding surface thoroughly, as paint buildup frequently causes intermittent faults. If all circuit tests pass but E-24 persists, the ECM may require replacement or professional reprogramming using Komatsu KEDC diagnostic software.

Step 5: Clear Codes and Perform Operational Test After repairs, clear fault codes using the service mode on the monitor or diagnostic software. Operate the machine through full hydraulic cycles for 15-20 minutes, monitoring for code recurrence. Check hydraulic oil quality—contaminated fluid often damages replacement solenoids within hours on used equipment.

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Disclaimer: This guide provides general troubleshooting procedures for informational purposes. Always consult the official Komatsu service manual for your specific machine serial number and seek professional diagnosis if unfamiliar with electrical systems or hydraulic components. Improper repairs may cause equipment damage or safety hazards.