| Part Number | 366-8821-00 (Verify exact replacement) |
| Compatible Model | Caterpillar E320D Excavator (Check machine serial number for exact fit) |
| Function | Main control unit for engine, hydraulics, and machine operations |
| Voltage Range | Typically 12V or 24V (Confirm with CAT specs) |
| Communication Protocol | CAT Data Link (CDL), CAN Bus (J1939 likely) |
| Common Symptoms of Failure | - Engine stalling or power loss - Hydraulic malfunctions - Diagnostic trouble codes (DTCs) - Electrical issues |
| Diagnostic Tools Required | CAT ET (Electronic Technician) or compatible diagnostic scanner |
| Replacement Notes | - Disconnect battery before replacement - May require reprogramming |
| Availability | - CAT OEM dealers (expensive) - Aftermarket/refurbished suppliers (cheaper) - Used parts markets (riskier) |
| Repair Options | Some companies specialize in ECU repair (cheaper than full replacement) |