Sumitomo SH220LC-6 Fault Code 380: Complete Diagnostic Guide

What is Sumitomo SH220LC-6 Fault Code 380?

Fault Code 380 on the Sumitomo SH220LC-6 excavator indicates a malfunction in the Engine Control Module (ECM) communication circuit or a failure in the main controller's internal system diagnostics. This code specifically relates to a breakdown in the CAN bus communication between the engine controller and the machine's primary control systems.

This fault is critical for the SH220LC-6 because it disrupts the coordinated operation between the engine management system and the hydraulic control unit. When communication fails, the excavator cannot properly regulate engine speed, hydraulic flow, or implement safety protocols. The Sumitomo SH220LC-6 relies heavily on integrated electronic controls, making this communication pathway essential for optimal machine performance and fuel efficiency.

Common Symptoms

When Code 380 is active, operators typically experience:

• Warning light illumination on the instrument panel, often accompanied by a check engine light or master caution indicator
• Reduced engine power or sudden derating to idle speed, preventing normal operation
• Erratic hydraulic response including inconsistent swing speed or boom/arm movement delays
• Intermittent engine stalling or failure to start, particularly after the machine has warmed up
• Loss of monitor display functions, with the digital screen showing error messages or going blank

Potential Causes

The most common technical reasons for Code 380 on used SH220LC-6 excavators include:

• Corroded or damaged CAN bus wiring harness, especially at known rub points near the turntable or along the boom base where cables flex repeatedly
• Failed ECM relay or power supply interruption to the engine controller
• Loose or oxidized connector pins at the main controller junction box, often located under the operator's cab
• Water intrusion into the ECM housing or main harness connectors due to failed seals
• Internal ECM failure from voltage spikes or age-related component degradation common in machines with 8,000+ operating hours

How to Troubleshoot and Fix Code 380

Step 1: Visual Harness Inspection Begin by thoroughly inspecting the CAN bus wiring harness from the ECM to the main controller. On used excavators, focus on areas where the harness passes through the swing bearing and along the undercarriage where abrasion commonly occurs. Look for chafed insulation, broken wires, or signs of previous repairs with electrical tape.

Step 2: Connector and Ground Testing Disconnect the main ECM connector and inspect all pins for corrosion, bent contacts, or moisture. Use a multimeter to verify proper ground continuity (should read less than 1 ohm resistance) at the ECM ground points. Check battery voltage at the ECM power supply pin (should read 24V nominal on this model).

Step 3: CAN Bus Communication Test Using Sumitomo diagnostic software or a compatible CAN bus scanner, verify communication signals between controllers. Check for proper termination resistance (should measure 60 ohms across CAN High and CAN Low terminals). If readings are incorrect, trace the harness for breaks or short circuits.

Step 4: Component Replacement If all wiring tests pass, the ECM itself may require replacement. Before ordering new parts for used equipment, verify the ECM part number matches your machine's serial number range, as Sumitomo made running changes to the SH220LC-6 electronics throughout production.

Disclaimer: This guide provides general diagnostic procedures. Always consult the official Sumitomo service manual for your specific machine serial number and consider professional diagnosis for complex electrical issues to avoid costly misdiagnosis.