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Service procedures 2026 firmware

HVC ECU Restore

Gen3/tasks/PROC_HVC_X_ECU-REPLACEMENT-RESTORE

Model 3 / YModel S / X (2021+)

What this task does

This routine writes the most recently saved High Voltage Controller (HVC) ECU backup data on the car computer to the newly installed HVC. During the routine, two CAN ECU redeploys will occur which is expected. The entire procedure will take approximately 15-20 minutes to complete. See Toolbox Article 6523500 for more specific details. Requirements: - New compatible HVC is installed (See Toolbox Article 6569500) - LV battery is supported by a LV maintainer - First responder loop is connected - Every connection within the ancillary bay is made

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
Service, Factory, DiagLinkActive

Procedure notes

This routine should NOT be run if a new HV battery was just installed. During the routine, pack contactors will open and close.

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
Service, Factory, DiagLinkActive

Procedure notes

This routine should NOT be run if a new HV battery was just installed. During the routine, pack contactors will open and close.

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
Service, Factory, DiagLinkActive

Procedure notes

This routine should NOT be run if a new HV battery was just installed. During the routine, pack contactors will open and close.

Task inputs (0)

No user inputs are listed in this firmware.

Related service tasks

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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+)