What is Komatsu PC210-10 Fault Code CA352?

Fault Code CA352 indicates a communication error or abnormality in the CAN (Controller Area Network) data transmission between the engine controller (ECM) and the monitor controller. This code appears when the engine's Electronic Control Module fails to receive or transmit proper signals through the machine's internal communication network.

On the Komatsu PC210-10, the CAN bus system is the central nervous system connecting all electronic controllers. When CA352 triggers, the ECM cannot properly communicate operational data to the monitor panel, which affects how engine parameters are displayed and logged. This is critical because the PC210-10's emission control system, fuel management, and diagnostics all depend on accurate data transmission between controllers. Without proper communication, the machine may enter protective derate mode or fail to report other critical fault conditions.

Common Symptoms

• Warning light illuminated on the monitor panel, often accompanied by a communication error message
• Intermittent or complete loss of engine parameter displays (RPM, coolant temperature, fuel level)
• Engine derate or power reduction, particularly under load conditions
• Inability to clear other fault codes or access complete diagnostic information through the monitor
• Erratic gauge behavior with readings that freeze, fluctuate wildly, or display default values

Potential Causes

The most common causes of CA352 on used PC210-10 excavators include:

Corroded or damaged CAN bus connectors at the ECM or monitor controller, particularly in machines exposed to moisture or operating in coastal/high-humidity environments.

Wiring harness damage where the CAN-H and CAN-L wires run along the chassis near hydraulic lines—a known rub point on this model that causes intermittent shorts.

Failed monitor controller or ECM internal communication circuitry, more common in high-hour machines (6,000+ hours).

Voltage supply issues affecting controller power, including corroded ground connections at the battery box or frame grounding points.

Previous repair attempts using non-genuine harnesses or connectors that don't meet CAN bus impedance specifications (120-ohm termination requirement).

How to Troubleshoot and Fix Code CA352

Step 1: Visual Inspection and Connector Check Begin by inspecting all CAN bus connectors at both the engine ECM (located on the right side of the engine) and the monitor controller (behind the cab panel). Look for green corrosion, bent pins, or moisture intrusion. Clean connectors with electrical contact cleaner and apply dielectric grease. On used excavators, check the main wiring harness routing from engine to cab for signs of abrasion against frame components.

Step 2: CAN Bus Continuity and Resistance Testing Using a digital multimeter, measure resistance between CAN-H and CAN-L terminals at the ECM connector (with harness disconnected). You should read approximately 60 ohms with both controllers connected (two 120-ohm terminating resistors in parallel). If you read infinite resistance, there's an open circuit in the harness. Also verify voltage supply to both controllers: key-on should show 24V at power pins.

Step 3: Monitor Communication with Diagnostic Software Connect Komatsu KOMTRAX or compatible diagnostic software to the machine's diagnostic port. Monitor live CAN bus traffic while operating the machine. If communication drops intermittently, flex the harness while monitoring—this often reveals worn wire insulation at bend points. For used machines with previous repairs, verify that all ground points (especially G101 near the battery and G304 at the cab mount) are clean and tight, as poor grounding is a frequent cause of communication errors.

Step 4: Component Replacement Protocol If testing reveals a faulty controller, replace the monitor controller first (less expensive and more commonly failed). After replacement, perform a CAN bus reset procedure using diagnostic software. If the ECM requires replacement, ensure the new unit is programmed with the correct machine serial number and configuration before installation.

Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Komatsu service manual for your specific machine serial number. If you lack proper diagnostic tools or experience with high-voltage systems, consult a certified Komatsu technician to avoid injury or further damage to electronic components.