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Service procedures 2026 firmware

HVC ECU Backup

Gen3/tasks/PROC_HVC_X_ECU-REPLACEMENT-BACKUP

What this task does

This routine creates a backup copy of High Voltage Controller (HVC) data and saves it onto the car computer. The backup data is needed when performing an HVC ECU Restore.

Vehicle & firmware coverage

Open a version to see its description, requirements, and input definitions. Hardware configuration and live vehicle checks also determine availability.

Model 3 / Y AMD · Firmware 2026.32.3
Vehicle coverage
2024+ Model 3, 2025+ Model Y, Model Y, Pre-2024 Model 3
Supported connection
Local connection
Vehicle state
Stationary · Parked; Stationary · Neutral
Gateway diagnostic level
Park, Service, Factory, DiagLinkActive

Task inputs (0)

No user inputs are listed in this firmware.

Model 3 / Y Intel · Firmware 2026.32.7
Vehicle coverage
Model Y, Pre-2024 Model 3
Supported connection
Local connection
Vehicle state
Stationary · Parked; Stationary · Neutral
Gateway diagnostic level
Park, Service, Factory, DiagLinkActive

Task inputs (0)

No user inputs are listed in this firmware.

Model S / X (2021+) AMD · Firmware 2026.20.6.1
Vehicle coverage
2021+ Model S, 2021+ Model X
Supported connection
Local connection
Vehicle state
Stationary · Parked; Stationary · Neutral
Gateway diagnostic level
Park, Service, Factory, DiagLinkActive

Task inputs (0)

No user inputs are listed in this firmware.

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Service procedures

After HV Battery Replacement

Before running this routine, a Controller Area Network (CAN) Electronic Control Unit (ECU) redeploy needs to pass. After a High Voltage (HV) Battery replacement, this routine runs all required tasks.

PROC_HVC_X_PACK-REPLACEMENT

Model 3 / Y Model S / X (2021+)
Service procedures

Clear HVC Battery Coolant Flood Alert

Clears the HVC battery coolant flood alert, BMS_a124_Battery_Coolant_Flood, if set. This routine shall only be executed after repairing the HV battery isolation issue.

PROC_HVC_X_CLEAR-BATTERY-COOLANT-FLOOD-ALERT

Model 3 / Y Model S / X (2021+)
Service procedures

Clear HVC Internal Isolation Alert

Clears the HVC internal isolation alert, BMS_a123_SW_Internal_Isolation, if set. This routine shall only be executed after repairing the HV battery isolation issue.

PROC_HVC_X_CLEAR-INTERNAL-ISOLATION-ALERT

Model 3 / Y Model S / X (2021+)
Service procedures

Clear HVC Isolation Condition

Clears the High Voltage Controller (HVC) isolation counters and alerts BMS_a027_SW_Repeated_Isolation_Failure_In_Drive, BMS_a172_SW_Isolation_Failure_In_Drive_Warning, BMS_a123_SW_Internal_Isolation, and BMS_a124_Battery_Coolant_Flood, if set. This routine shall only be executed after repairing a HV system component for loss of isolation.

PROC_HVC_X_CLEAR-ISOLATION-CONDITION

Model 3 / Y Model S / X (2021+)