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Service procedures 2026 firmware

Write or Read BMS Pyro Type

ModelSX/tasks/PROC_BMS_X_PYROFUSE-READWRITE-TYPE-YEAR-MONTH

What this task does

This routine will write or read the pyro data to/from the Battery Management System (BMS). Important: - A new battery-powered hybrid pyro or thermal/sand fuse should never be installed in the HV battery. See Article 6239500 for more details. - It is important to only update the type when a new self-powered hybrid pyro has been installed or when a sand fuse has been physically confirmed to be installed and the BMS needs to be updated.

Vehicle & firmware coverage

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

Model S / X (legacy) Legacy infotainment · Firmware 2026.14.6
Vehicle coverage
Pre-2021 Model S, Pre-2021 Model X
Supported connection
Local connection
Vehicle state
Stationary · Neutral; Stationary · Parked
Gateway diagnostic level
Factory, DiagLinkActive, Service, Park

Task inputs (2)

Write or Read Pyro Data

write_or_read · String

WRITE the new pyro type or READ the current pyro data from the BMS.

Firmware default: WRITE

Options: WRITE, READ

Pyro Type

PYRO_TYPE · String

Select SELFPOWERED_HYBRIDPYRO if the new hybrid pyro part number installed contains 1090924, 1111313, or 1111445. Select SAND_FUSE if you have physically confirmed one is currently installed within the HV battery.

Firmware default: SELFPOWERED_HYBRIDPYRO

Options: SELFPOWERED_HYBRIDPYRO, SAND_FUSE

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Service procedures

Attempt to Clear Blocked Pack Contactors

This routine will execute various Battery Management System (BMS) clear/reset routines in an attempt to clear blocked pack contactors. Keep in mind that even if all internal routines PASS, pack contactors may still be blocked from closing due to other extrinsic conditions.

PROC_BMS_X_CLEAR-BLOCKED-CONTACTORS

Model S / X (legacy)
Service procedures

BMS - Clear Isolation Counters

Clears the Battery Management System (BMS) isolation counters, which clears BMS_w/f027_SW_Drive_Iso_Repeated and BMS_w/f172_SW_Drive_Iso_Warning alerts. Execute this routine after repairing any isolation issue on the vehicle's High Voltage (HV) system. The BMS isolation counters latch the alerts BMS_w/f027 and BMS_w/f172 when reaching a specific count threshold.

PROC_BMS_X_CLEAR-ISOLATION-ALERT-COUNTERS

Model S / X (legacy)
Communication checks

BMS CAN Communication Test

This routine will test if the Battery Management System (BMS) is communicating over CAN to the Gateway.

PING-TP_BMS

Model S / X (legacy)
Service procedures

BMS ECU Backup

This routine creates a backup copy of data from the Battery Management System (BMS) ECU and saves it onto the car computer. The backup data is needed when performing a BMS ECU Restore.

PROC_BMS_X_ECU-REPLACEMENT-BACKUP

Model S / X (legacy)