| 301 | EEPROM display error | EEPROM memory of the PCB (display/main) corrupted or unreadable; check 5V/3.3V on the PCB and the display/BUS harness. If it persists after reset, replace/reprogram the PCB. |
| 302 | Electronic communication fault | Communication fault between the main PCB and display/interface; check the continuity of the BUS/connectors. If the wiring is OK, it is usually a PCB fault. |
| 303 | Main PCB fault | Self-diagnosis detects an internal fault in the main PCB; check voltages/regulators and moisture damage. If everything is correct and the error persists, replace the PCB. |
| 305 | Main PCB fault | Internal fault of the main PCB; check low voltage supply and connectors. If there are no external anomalies, replace the board. |
| 306 | Main PCB fault | Recurrent internal fault in the PCB; check 5V/12V, perform visual inspection and test with a known PCB. If confirmed, replace. |
| 307 | Main PCB fault | Internal fault of the main PCB; after checking wiring/power supply and ruling out external causes, proceed with replacing the board. |
| A 39 | MCU 1 fault | Microcontroller fault in the main PCB (lock/damage); check 5V and clock/crystal. If it does not start after reset and wiring is OK, replace the PCB. |
| A 40 | MCU 2 fault | Second level microcontroller fault on the PCB; same checks (power supply/oscillator). If it persists, replace the board. |
| E 37 | Problema de comunicación con la placa electrónica principal | The interface is not communicating with the main PCB; check the harness and connectors between the display and main. If the BUS is correct, the main PCB is damaged. |
