What is Komatsu PC450-7 Fault Code E247?

Komatsu PC450-7 Fault Code E247 indicates a malfunction in the proportional solenoid valve control circuit for the excavator's hydraulic system. Specifically, this code triggers when the Engine Control Module (ECM) detects an abnormal voltage or current flow to one of the proportional pressure control solenoids that regulate main pump output and hydraulic system pressure.

This fault is critical because the proportional solenoid valves directly control the hydraulic pump's displacement and system pressure. When the ECM cannot properly communicate with or control these solenoids, the PC450-7's hydraulic performance becomes compromised, potentially affecting all machine functions including boom, arm, bucket, and swing operations.

Common Symptoms

When Code E247 is active on a Komatsu PC450-7, operators typically experience:

• Hydraulic power loss or significantly reduced implement speed across multiple functions
• Erratic or jerky hydraulic movements, particularly during combined operations
• Monitor panel warning light illumination with possible audible alarm
• Automatic derate to economy mode or reduced engine RPM limit
• Sluggish response when attempting simultaneous multi-function work

Potential Causes

The most common technical causes for E247 on used PC450-7 excavators include:

• Faulty proportional solenoid valve coil with resistance outside specification (typically 3-6 ohms when cold)
• Damaged or corroded wiring harness connectors at the main pump solenoid location
• Wire chafing or breaks in the harness routing near the hydraulic tank or pump—a known wear point on higher-hour machines
• Internal short circuit or open circuit within the solenoid valve assembly
• Contaminated hydraulic oil causing solenoid spool sticking
• ECM internal driver circuit failure (less common but possible in used equipment)

How to Troubleshoot and Fix Code E247

Step 1: Visual Inspection Inspect the wiring harness routing from the ECM to the hydraulic pump proportional solenoids. On used excavators, check for harness wear where it contacts the pump mounting bracket or hydraulic tank edge. Examine all connector pins for corrosion, bent terminals, or hydraulic oil contamination.

Step 2: Electrical Testing Using a digital multimeter, disconnect the solenoid connector and measure coil resistance. Specifications should be 3-6 ohms at room temperature. Also check for shorts to ground. With ignition on (engine off), check for proper supply voltage (typically 12V) at the harness connector from the ECM.

Step 3: Component Testing If electrical values are correct, the solenoid valve itself may be mechanically stuck. Remove the proportional solenoid and inspect for contamination or physical damage. On used machines, consider replacing the entire valve assembly rather than just the coil if hydraulic oil contamination is present.

Step 4: Advanced Diagnostics Use Komatsu KOMTRAX or compatible diagnostic software to monitor real-time solenoid command signals versus actual current draw, which can reveal intermittent ECM driver issues.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu service manual and consider professional diagnostic services for complex electrical or hydraulic system repairs.