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Service procedures 2026 firmware

Read or Write HV Battery Birthday

Gen3/tasks/PROC_HVC_X_READ-WRITE-PACK-BIRTHDAY

What this task does

This routine provides the ability to read or write the HV battery calibration birthday from/to the High Voltage Controller (HVC).

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 · Neutral; Stationary · Parked
Gateway diagnostic level
Park, Factory, DiagLinkActive, Service

Procedure notes

Entering an incorrect birthday will result in inaccurate displayed range values. Pack contactors will open and then close shortly after.

Task inputs (2)

Operation

OPERATION · String

Select wether to read or write the HV battery birthday.

Firmware default: READ

Options: READ, WRITE

Birthday (Epoch)

BIRTHDAY_EPOCH · Int

If write operation selected, enter the birthday as a 10 character integer epoch value.

Firmware default: Not specified

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

Procedure notes

Entering an incorrect birthday will result in inaccurate displayed range values. Pack contactors will open and then close shortly after.

Task inputs (2)

Operation

OPERATION · String

Select wether to read or write the HV battery birthday.

Firmware default: READ

Options: READ, WRITE

Birthday (Epoch)

BIRTHDAY_EPOCH · Int

If write operation selected, enter the birthday as a 10 character integer epoch value.

Firmware default: Not specified

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 · Neutral; Stationary · Parked
Gateway diagnostic level
Park, Factory, DiagLinkActive, Service

Procedure notes

Entering an incorrect birthday will result in inaccurate displayed range values. Pack contactors will open and then close shortly after.

Task inputs (2)

Operation

OPERATION · String

Select wether to read or write the HV battery birthday.

Firmware default: READ

Options: READ, WRITE

Birthday (Epoch)

BIRTHDAY_EPOCH · Int

If write operation selected, enter the birthday as a 10 character integer epoch value.

Firmware default: Not specified

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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+)