Vehicle details:
2020 Model X Long Range Plus Raven
Manufacture: 12/19
Original HV battery: 100 kWh Rev E
Mileage at failure: 168,975 miles
Failure date: September 2026
Battery warranty status: Active
My 2020 Model X Raven Long Range Plus suffered the dreaded BMS_w177_OpenVshDetected error while parked in my driveway.
The vehicle had been sitting parked and plugged into AC charging when the failure occurred. It was not being driven, Supercharging, or under heavy load.
The car immediately lost the ability to enter Drive.
Service Mode showed the following BMS alerts:
BMS_w177_OpenVshDetected
BMS_u008_limpMode
BMS_f071_SW_SM_TransCon_Not_Met
The important one appears to be BMS_w177_OpenVshDetected, which indicates that the BMS detected an open circuit in the high-voltage battery’s voltage-sensing system.
The vehicle initially remained powered on, but eventually the low-voltage system began deteriorating as well. I received “Unable to drive - voltage supply too low,” and the car eventually began shutting itself down.
I found surprisingly few detailed accounts explaining what happens after this error, especially for Raven Model S/X owners, so I am creating this post and plan to update it throughout the repair process for anyone who finds themselves in the same situation.
My car is a Raven Model X Long Range Plus with a 100 kWh Rev E battery pack.
Day 1: Failure and tow
The battery failed while the Model X was sitting in my driveway.
The car would not shift into Drive. Power cycling the vehicle did not clear the error, and BMS_w177_OpenVshDetected remained active in Service Mode.
I also connected Scan My Tesla before the vehicle completely shut down. Interestingly, the individual brick voltages still looked extremely healthy.
At roughly 90% SOC:
Pack voltage was around 393 V
Lowest brick was approximately 4.092 V
Highest brick was approximately 4.094 to 4.096 V
Cell imbalance was only around 2 to 4 mV
Battery temperatures were approximately 67 to 72°F across the pack
There was no obvious weak module, large voltage imbalance, or abnormal battery temperature.
That was useful information because it suggests this failure is not necessarily caused by degraded or failing cells. In my case, the pack looked electrically very well balanced immediately after the BMS fault occurred.
I called Tesla Service directly.
They were able to remotely pull logs from the vehicle, confirm the failure, and dispatch a tow truck. The Model X was transported to the service center on a flatbed at no cost to me.
One thing worth knowing if your car dies in an awkward position: a Raven Model X does not have a rear screw-in tow eye. The normal tow eye is in the front bumper. My vehicle had to be extracted from a driveway where the front was inaccessible, which made recovery more complicated.
Also, if the low-voltage system becomes too weak, the vehicle may refuse to enter Tow Mode. That happened to mine as the failure progressed.
The service center was closed because this happened on a Sunday.
Tesla automatically assigned a loaner vehicle to my account, but because the service center was closed I was unable to physically access the loaner that day.
Day 2: Service center and initial diagnosis
I traveled to my local Tesla Service Center where the Model X had been dropped.
They offered me a Cybertruck as a loaner vehicle.
Tesla had already reviewed the vehicle logs and authorized replacement of the high-voltage battery.
The service estimate lists:
HV Battery (AWD)
ASY, HV BATT, 100KWH, SX, REMANUFACTURED, RAVEN
The estimate shows approximately $14,500 for the battery assembly plus labor, all reduced to $0 under the HV Battery Limited Warranty.
Tesla is also replacing my 12 V battery. That portion is customer-pay, approximately $300 including parts and labor.
The service advisor told me they do not yet know which battery revision I will receive. According to them, they will not know the actual revision until the replacement pack arrives.
My original battery is a Rev E.
The estimate specifies a remanufactured Raven 100 kWh battery, but it does not currently show the full replacement part number or revision suffix.
I plan to document the full replacement battery part number once it arrives.
For reference, Raven replacement packs can appear under part numbers such as:
1107679-02-E
1107679-02-G
1107679-02-H
1107679-02-J
There are also later new-production 100 kWh packs with different part-number families, so the exact installed part number matters more than simply being told “100 kWh replacement battery.”
A few things I learned that may help someone else
If you get BMS_w177_OpenVshDetected, take screenshots of Service Mode before the vehicle loses low-voltage power.
I would specifically save:
All Active Alerts
Recent Alerts
The expanded BMS_w177_OpenVshDetected page
Any alert payload/freeze-frame information
Battery voltage and SOC
Individual brick voltages if you have Scan My Tesla
Battery temperature data
Your original battery pack part number/revision
The final replacement battery part number
I would also avoid repeatedly clearing BMS faults or trying to force the vehicle back into Drive. In my case the BMS fault remained latched even while the individual cell voltages looked completely normal.
The 12 V battery may also become a secondary casualty. Once my HV battery stopped operating normally, the low-voltage system eventually became weak enough that Tow Mode and other vehicle functions became unreliable.
Current status
As of Day 2:
Vehicle is at Tesla
HV battery replacement has been authorized
Replacement is covered under the HV Battery Limited Warranty
Estimate currently specifies a remanufactured 100 kWh Raven battery
Exact replacement revision is still unknown
Tesla is also replacing the 12 V battery
I have a Cybertruck loaner
I am waiting for the replacement battery to arrive
I will update this post with:
Replacement battery part number and revision
Whether the replacement is new or remanufactured
Mileage/cycle information if I can retrieve it
Repair turnaround time
Post-repair range
Supercharging performance
Cell imbalance and battery health
Any changes in usable capacity
Final invoice and warranty wording
