What is Komatsu PC210LC-10 Fault Code DW45KB?

Fault Code DW45KB indicates a communication error between the engine controller (ECM) and the hydraulic pump controller (CLSS - Closed-Center Load Sensing System) on the Komatsu PC210LC-10 excavator. This diagnostic trouble code specifically signals that the CAN bus communication link has experienced an interruption or abnormal signal transmission between these critical control modules.

The PC210LC-10 relies on precise coordination between the SAA6D107E-1 engine ECM and the CLSS hydraulic controller to optimize fuel efficiency and hydraulic performance. When communication fails, the machine cannot properly match engine power output with hydraulic demand, resulting in reduced operational efficiency and potential component protection modes. This fault is particularly critical because the CLSS system manages variable pump displacement based on real-time load requirements—without proper communication, your excavator defaults to conservative settings that limit productivity.

Common Symptoms

• Hydraulic system operates in reduced power mode with noticeably slower cycle times and weak digging force
• Engine struggles to match load demands, causing excessive RPM fluctuation during combined operations
• Warning indicator light illuminates on the monitor panel with fault code displayed
• Machine may enter derate mode, limiting maximum engine RPM to 1,600-1,800 range
• Intermittent or complete loss of auto-idle function and power mode selection features

Potential Causes

The DW45KB code on used PC210LC-10 excavators typically stems from these technical issues:

• CAN bus wiring harness damage at known rub points near the engine firewall or along the right-hand frame rail where harnesses pass through bulkheads
• Corroded or loose connector terminals at the ECM (located behind the operator cab) or CLSS controller (mounted near the hydraulic pumps)
• Failed termination resistors within the CAN communication network (120-ohm resistors at network endpoints)
• ECM or CLSS controller internal failure, though less common than wiring/connector issues in machines with 5,000+ operating hours
• Voltage supply problems to either controller due to degraded main relay or battery connection issues
• Water intrusion into controller housings from compromised seals—common in machines operated in wet conditions

How to Troubleshoot and Fix Code DW45KB

Step 1: Visual Inspection of Communication Network Begin by thoroughly inspecting the CAN bus harness routing between the engine ECM and CLSS controller. On used excavators, check specifically where the harness passes through the cab mounting area and near the hydraulic pump assembly. Look for abraded wire insulation, pinched cables, or evidence of previous repair attempts. Inspect all connector pins for corrosion, bent terminals, or pushed-back pins—clean with electrical contact cleaner and dielectric grease.

Step 2: Electrical Testing with Diagnostic Tools Using a digital multimeter, verify the CAN-High and CAN-Low signal wires show proper resistance. With ignition off and both controllers disconnected, measure resistance between CAN-High and CAN-Low terminals—you should read approximately 60 ohms (two 120-ohm termination resistors in parallel). Connect Komatsu KOMTRAX or compatible diagnostic software to monitor live CAN bus traffic and identify which controller isn't communicating.

Step 3: Controller Power Supply Verification Measure voltage supply at both the ECM and CLSS controller connectors with ignition on—should read 24-26 volts DC. Check ground circuits for resistance below 0.5 ohms. On used machines, corroded ground points behind the cab are frequent culprits.

Step 4: Component Replacement Protocol If wiring and power supply test good, replace the termination resistors first (low-cost diagnostic step). If fault persists, the CLSS controller typically fails more frequently than the ECM on high-hour machines. Before replacing expensive controllers, verify with dealer-level diagnostics that internal controller failure is confirmed—many used excavators have been misdiagnosed, resulting in unnecessary part replacement.

For used excavators, always check service history for previous hydraulic system modifications or non-OEM controller replacements that may affect CAN communication protocols.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu PC210LC-10 service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs may cause additional system damage.