What is Komatsu PC110-8M0 Fault Code B@HANS?

Fault Code B@HANS on the Komatsu PC110-8M0 excavator indicates a communication error or data corruption within the machine's internal network system, specifically affecting the CAN (Controller Area Network) bus communication between the main controller and peripheral control modules. This code typically appears when the Electronic Control Module (ECM) detects abnormal or incomplete data transmission across the machine's digital communication network.

The PC110-8M0 relies on continuous digital communication between its hydraulic controller, engine management system, and monitor display unit. When this communication breaks down, the machine cannot properly coordinate functions, potentially leading to reduced performance or complete operational shutdown. This fault is particularly critical because it can mask other underlying issues, making accurate diagnosis essential for maintaining optimal machine performance.

Common Symptoms

• Intermittent or complete loss of monitor display functions, with gauges freezing or showing incorrect readings
• Unexpected machine derating or engine power reduction despite no apparent mechanical issues
• Multiple warning lights illuminating simultaneously on the instrument cluster without clear pattern
• Erratic hydraulic response or delayed actuation of boom, arm, or bucket functions
• Failure to start or immediate shutdown after ignition, particularly in cold weather conditions

Potential Causes

The most common causes of Code B@HANS on used PC110-8M0 excavators include:

Corroded or loose CAN bus connectors behind the operator cab, especially at the main harness junction point near the swing bearing—a known wear point on this model due to continuous rotation stress.

Damaged wiring harness from rodent activity or physical abrasion, particularly along routing paths near the battery box and hydraulic pump area where cables experience vibration.

Failed network termination resistor within the ECM or peripheral modules, often deteriorated in machines with 5,000+ operating hours.

Water intrusion into control module housings, common in machines operated in wet conditions without proper seal maintenance.

Faulty ECM or display unit with internal circuit board corrosion, especially in machines stored outdoors without environmental protection.

How to Troubleshoot and Fix Code B@HANS

Step 1: Visual Inspection and Connector Check Begin by inspecting all CAN bus connectors throughout the machine, focusing on the main harness connection behind the cab and at the swing post. Disconnect each connector, examine for corrosion, bent pins, or moisture, and clean with electrical contact cleaner. Check the wiring harness routing for visible damage, particularly where cables pass through metal grommets or near moving components. On used excavators, this physical inspection often reveals the root cause without requiring advanced diagnostics.

Step 2: Resistance and Continuity Testing Using a digital multimeter, measure the CAN-High and CAN-Low line resistance at the ECM connector (typically 60 ohms between CAN-H and CAN-L when properly terminated). Check for continuity along the entire harness length and verify there are no short circuits to ground. Test the termination resistors at both ends of the network—failed resistors often measure open circuit or incorrect values.

Step 3: Advanced Diagnostics with Komatsu KTEC Software Connect Komatsu's proprietary diagnostic software via the service port to monitor live CAN bus traffic and identify which specific module is failing to communicate. The software will show packet error rates and help isolate whether the issue originates from the ECM, hydraulic controller, or display unit. For used machines, update the ECM firmware if outdated, as Komatsu released patches addressing communication bugs in early PC110-8M0 production units.

Step 4: Component Replacement and Verification If diagnostics confirm a failed component, replace the faulty module or harness section using genuine Komatsu parts to ensure proper communication protocol compatibility. After replacement, clear all codes and perform a function test of all hydraulic and electrical systems to confirm proper network operation.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu service manual for your specific machine serial number and consider engaging a certified Komatsu technician for complex electrical diagnostics, especially when dealing with safety-critical systems on used equipment.