What is Komatsu PC200LC-8 Fault Code E15CA2555?

Fault Code E15CA2555 indicates a communication error or data transmission failure between the engine controller (ECM) and the hydraulic pump controller (PPC) on the Komatsu PC200LC-8 excavator. This code specifically relates to the CAN (Controller Area Network) bus system that allows critical machine components to share operational data in real-time.

The PC200LC-8 relies on seamless communication between its electronic control modules to optimize fuel efficiency, hydraulic response, and overall machine performance. When the ECM and PPC cannot communicate properly, the excavator's computer system cannot coordinate engine output with hydraulic demand, leading to reduced productivity and potential component protection modes. This fault is particularly critical because it affects the machine's ability to match engine speed with hydraulic load requirements, a core function of Komatsu's advanced control technology.

Common Symptoms

• Amber or red warning lights illuminated on the instrument cluster, specifically communication-related indicators
• Reduced hydraulic power or sluggish implement response, even when engine RPM appears normal
• Engine derating or automatic limitation to lower RPM ranges as a protective measure
• Erratic machine behavior such as inconsistent swing speed or boom response under varying loads
• Multiple fault codes appearing simultaneously, indicating widespread communication disruption across the CAN network

Potential Causes

The most common technical causes for E15CA2555 on used PC200LC-8 excavators include:

• Corroded or damaged CAN bus connectors between the ECM and PPC, especially at harness connection points behind the operator's cab
• Frayed or severed wiring in the main harness, particularly where cables route near the swing bearing or along the boom base (known wear points on this model)
• Failed termination resistors on the CAN network, which maintain proper signal voltage across the communication lines
• ECM or PPC controller failure, though less common than wiring issues in used machines
• Low battery voltage or poor grounding, which can disrupt digital communication signals on older equipment
• Aftermarket component interference, such as non-OEM monitors or third-party telematics devices improperly tapped into the CAN system

How to Troubleshoot and Fix Code E15CA2555

Step 1: Preliminary Inspection Begin with a thorough visual inspection of all wiring harnesses between the engine bay and hydraulic pump area. On used excavators, pay special attention to harness routing near pivot points, the swing motor, and anywhere cables contact metal surfaces. Look for abraded insulation, exposed copper, or corroded connectors—common issues on machines with 5,000+ operating hours.

Step 2: CAN Bus Voltage Testing Using a digital multimeter set to DC voltage, backprobe the CAN-High and CAN-Low wires at the ECM connector (typically green and yellow wires on Komatsu systems). With the key on and engine off, you should measure approximately 2.5V on CAN-High and 2.5V on CAN-Low at rest. Significant deviation suggests termination resistor failure or short circuits.

Step 3: Check Termination Resistors With the key off and battery disconnected, measure resistance between CAN-High and CAN-Low terminals. A properly terminated network should read 60 ohms. If you measure infinite resistance, one or both termination resistors have failed and must be replaced.

Step 4: Connector Cleaning and Repair Disconnect all CAN network connectors along the suspect circuit. Clean pins with electrical contact cleaner and inspect for bent pins or moisture intrusion. On used machines, connector corrosion is often the root cause. Apply dielectric grease to all connections before reassembly.

Step 5: Advanced Diagnostics If physical inspection reveals no issues, connect Komatsu diagnostic software (KOMTRAX or PC-based diagnostic tool) to monitor real-time CAN bus traffic. This will identify whether the ECM or PPC is failing to transmit data. Replace the faulty controller only after confirming wiring integrity.

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. If you lack proper diagnostic tools or electrical troubleshooting experience, consult a certified Komatsu technician to prevent further damage to expensive electronic components.