What is Komatsu PC200-10 Fault Code AB00KE?

Fault Code AB00KE on the Komatsu PC200-10 excavator indicates a communication error or malfunction in the hydraulic system control circuit, specifically related to the pump control solenoid valve or its associated wiring harness. This code is generated when the machine's Electronic Control Module (ECM) detects an abnormal signal or loss of communication with the hydraulic pump control system.

This fault is critical because the PC200-10's advanced CLSS (Closed-Center Load Sensing System) relies on precise electronic control of hydraulic flow. When AB00KE appears, the ECM cannot properly regulate pump output, directly affecting machine performance, fuel efficiency, and operator control. The hydraulic system may enter a default or derate mode to prevent damage, significantly reducing productivity on jobsites.

Common Symptoms

When fault code AB00KE is active on your Komatsu PC200-10, operators typically experience:

• Hydraulic system derate: Noticeable loss of boom, arm, or swing speed, particularly under load
• Warning indicator: Monitor panel displays the fault code along with a hydraulic system warning light
• Erratic hydraulic response: Inconsistent or jerky movements when operating multiple functions simultaneously
• Increased fuel consumption: ECM defaults to less efficient pump control settings
• Intermittent operation: Fault may appear and disappear, especially during temperature changes or machine vibration

Potential Causes

The most common technical causes for AB00KE on used PC200-10 excavators include:

• Faulty pump control solenoid valve: Internal coil failure or mechanical sticking due to contaminated hydraulic oil
• Damaged wiring harness: Known friction point near the pump mounting bracket where harness rubs against frame components
• Corroded or loose connectors: Particularly the 8-pin connector at the pump solenoid, vulnerable to moisture ingress
• ECM internal fault: Less common, but possible in high-hour machines with electrical system history
• Low system voltage: Weak batteries or failing alternator preventing proper solenoid actuation (requires minimum 22V for proper operation)
• Contaminated hydraulic oil: Metal particles or water causing solenoid valve sticking

How to Troubleshoot and Fix Code AB00KE

Step 1: Visual Inspection Using Komatsu's KOMTRAX diagnostic software or an aftermarket scan tool, confirm the fault code and check for additional related codes. Inspect the pump control solenoid valve harness along its entire route, paying special attention to the area where it passes near the pump mounting bracket—a known rub point on used PC200-10s. Look for abraded insulation, corrosion on the connector pins, or oil contamination.

Step 2: Electrical Testing Disconnect the solenoid valve connector and use a digital multimeter to check resistance across the solenoid coil terminals. Specification should read between 3.5-4.5 ohms at room temperature. Next, check for battery voltage (24V nominal) at the supply wire with ignition on. Use a test light or oscilloscope to verify the ECM is sending proper PWM (Pulse Width Modulation) signals to the solenoid during operation.

Step 3: Component Testing and Replacement If electrical values are within specification, remove the pump control solenoid valve and inspect for physical damage or contamination. On used excavators, internal sticking due to degraded hydraulic oil is common—consider cleaning with approved solvent or replacement. Check hydraulic oil quality; metallic contamination indicates pump wear. Replace corroded connectors and re-route harnesses away from friction points using proper wire loom protection. Clear codes, test operate, and monitor for recurrence.

---

Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Komatsu service manual for your specific machine serial number and software version. For complex electrical diagnostics or warranty concerns, contact an authorized Komatsu dealer or certified heavy equipment technician.