What is Doosan Excavator Fault Code E000654-21?

Fault Code E000654-21 indicates a communication error or data mismatch between the Engine Control Module (ECM) and the Machine Controller in Doosan excavators. This diagnostic trouble code (DTC) specifically points to a CAN bus communication failure or inconsistent signal transmission between these critical control systems.

This fault affects the Controller Area Network (CAN) system, which serves as the digital nervous system connecting the engine management system to the machine's main controller. When this communication breaks down, the excavator's integrated systems cannot properly coordinate engine performance with hydraulic demands, potentially leading to operational inefficiencies or complete machine shutdown. For used Doosan excavators, this code is particularly concerning as it can indicate deteriorating wiring harnesses, corroded connectors, or aging control modules that are common in machines with higher operating hours.

Common Symptoms

• Warning lamp illumination on the instrument cluster, often accompanied by a "Check Engine" or communication error message on the display
• Reduced engine power or derate mode where the ECM limits engine output due to inability to receive proper load demand signals
• Erratic engine RPM behavior or failure to respond correctly to throttle inputs
• Intermittent loss of monitoring data on the display panel, with gauges freezing or showing incorrect readings
• Hydraulic system performance issues, including sluggish response times or inconsistent attachment operation

Potential Causes

The most common technical causes for E000654-21 in used Doosan excavators include:

• Damaged or corroded CAN bus wiring harness, particularly at flex points near the engine mount or cab pivot areas where cable movement causes insulation wear
• Loose or oxidized connector pins at the ECM or machine controller connection points, especially in machines exposed to moisture or harsh environments
• Failed termination resistor on the CAN bus network (typically 120-ohm resistors at network endpoints)
• ECM or machine controller internal fault, often due to voltage spikes, water intrusion, or component age in higher-hour machines
• Incompatible or corrupted software versions between ECM and machine controller, sometimes occurring after partial system updates
• Grounding issues affecting the communication circuit, common in used machines with battery cable corrosion or frame grounding point deterioration

How to Troubleshoot and Fix Code E000654-21

Step 1: Visual Inspection and Connector Check Begin by thoroughly inspecting the CAN bus wiring harness from the ECM to the machine controller. On used excavators, pay special attention to harness routing near moving components, engine mounts, and areas where cables pass through bulkheads. Look for chafed insulation, pinched wires, or signs of previous repairs. Disconnect and inspect all related connectors, checking for bent pins, green corrosion, or moisture intrusion. Clean connector contacts with electrical contact cleaner and apply dielectric grease before reconnection.

Step 2: CAN Bus Network Testing Using a digital multimeter, measure the CAN-High and CAN-Low resistance between the two communication wires with the system powered off and all modules disconnected. You should read approximately 60 ohms (two 120-ohm termination resistors in parallel). If the reading is significantly different, check termination resistors and network integrity. With the system powered on, measure voltage between CAN-High and CAN-Low—you should see approximately 2.0-2.5V DC at rest, with fluctuations during communication attempts.

Step 3: Advanced Diagnostics with Manufacturer Software Connect Doosan diagnostic software (DMS or equivalent) to access detailed communication logs and real-time data streams. Monitor for specific communication timeout errors or data packet failures that pinpoint whether the ECM or machine controller is failing to respond. Check for available software updates for both modules, as communication protocol mismatches are common in used machines that have undergone partial system upgrades. If diagnostics confirm a module failure rather than wiring issues, consider sourcing a remanufactured or tested-used control module as a cost-effective solution for older equipment.

Step 4: Grounding and Power Supply Verification Verify all ground connections for both the ECM and machine controller, as poor grounding is frequently overlooked in used equipment. Check for battery voltage stability during cranking and operation—voltage drops below 10.5V during starting can cause communication initialization failures. Inspect the main power supply relay and fusing for the control modules.

Disclaimer: This guide provides general troubleshooting information for Doosan excavator fault code E000654-21. Always consult the manufacturer's service manual for your specific model and serial number. If you're uncomfortable performing electrical diagnostics, or if the fault persists after basic troubleshooting, consult a certified Doosan technician or qualified heavy equipment diesel mechanic to prevent further damage to electronic systems.