What is Doosan DX380-9C Fault Code E000027-07?

Fault Code E000027-07 on the Doosan DX380-9C indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically a communication timeout or data link failure between the main controller and the engine management system. This code is part of Doosan's proprietary diagnostic system and signals that the excavator's Electronic Control Unit (ECU) is not receiving proper signals from the Engine ECM through the CAN bus network.

This fault is critical for the DX380-9C because modern Doosan excavators rely on continuous communication between multiple control modules to optimize engine performance, hydraulic response, and emissions control. When communication breaks down, the machine may enter limp mode or experience reduced operational capabilities to prevent potential damage.

Common Symptoms

• Warning light illuminated on the instrument cluster, often accompanied by a check engine light or master warning indicator
• Noticeable power derate or restricted engine RPM, preventing the machine from reaching full operating capacity
• Erratic hydraulic performance, including sluggish boom, arm, or swing operations due to ECM coordination failure
• Intermittent engine shutdown or failure to start, particularly after the machine has been operating for extended periods
• Display screen errors showing communication fault messages or blank readings for engine parameters (temperature, pressure, RPM)

Potential Causes

The E000027-07 code typically stems from electrical or network communication issues common in used excavators:

• Damaged or corroded CAN bus wiring harness, especially at known rub points near the engine firewall or along the right-side chassis rail where the harness routes to the ECM
• Loose or oxidized connector pins at the ECM or main controller junction boxes, particularly the 24-pin main harness connector
• Failed Engine ECM due to moisture intrusion, vibration damage, or component aging in high-hour machines
• Low voltage supply to the ECM caused by weak batteries, corroded battery terminals, or failing alternator output
• Software version mismatch between the main controller and engine ECM after previous repair attempts or component replacements

How to Troubleshoot and Fix Code E000027-07

Step 1: Verify Power Supply and Ground Connections Using a digital multimeter, check that the ECM is receiving proper voltage (typically 24V DC) at the power supply pins. Inspect both the positive feed and ground connections for corrosion, particularly at the chassis ground points behind the cab. Clean all connections with electrical contact cleaner and apply dielectric grease.

Step 2: Inspect CAN Bus Communication Lines Locate the CAN-High and CAN-Low wires (usually twisted pair, orange/blue or yellow/green depending on harness year) running between the main controller and engine ECM. Check for continuity and proper termination resistance (should read approximately 60 ohms between CAN-H and CAN-L with both modules connected). On used excavators, pay special attention to harness routing near the hydraulic pump where vibration and heat can cause insulation breakdown.

Step 3: Perform ECM Communication Test Connect Doosan DMS (Diagnostic Master System) software or compatible diagnostic tool to the service port. Attempt to communicate with both the main controller and engine ECM separately. If one module responds while the other doesn't, isolate that specific module. For used machines, inspect the ECM connector for pushed-back pins, moisture, or corrosion—a common issue after years of exposure to hydraulic mist and engine bay heat.

Step 4: Check for Software and Component Compatibility Verify that the ECM firmware version matches the main controller specifications using diagnostic software. Mismatched software versions after replacement parts installation can trigger persistent communication faults. If replacing an ECM on a used excavator, ensure you're using a genuine Doosan part or properly programmed remanufactured unit.

Disclaimer: This guide provides general troubleshooting information for the Doosan DX380-9C fault code E000027-07. Excavator electrical systems are complex and potentially dangerous. Always consult your machine's service manual and consider professional diagnosis by a certified Doosan technician, especially when dealing with ECM replacement or CAN bus network repairs.