I'm posting this as FYI for folks in case you have the same BMS w305 error (mine came with additional low voltage-service requested vehicle may not start, and air suspension disabled). 2018 Model S 100. 30k miles.
Problem: I was driving from Austin to Dallas, in this abnormally cold weather 10-22F. After supercharging at a stop, I received a brief BMS w305 error, service requested. It disappeared after a soft reset (two thumbs + brake). Once in Dallas, I supercharged in evening at 10F, 80% power, and then BMS w305 error appeared again, with low voltage may not start, plus air suspension disabled errors --- then while plugged into the supercharger MS bricked itself (touch screens worked, couldn't drive, nor unplug). I did another Soft Reset to reboot, allowing me to then unplug the supercharger. Then I did a hard reset (power down). Then I could drive it to the Tesla Service Center in Dallas. Where I parked it overnight until morning, uber back to my hotel. Shout out to Dallas Plano Service team! They squeezed me first thing to diagnose. Thank you!
Issue: BMS w305 means the battery warmer must be replaced. Tech said it was overworking at 10F to "precondition the battery" at the supercharger. It is a quick 30min install - if they have the part. Dallas doesn't have the part.
No Parts - How to Manage Issue - Tech's Suggestion: His advice was -- typically the component will last several weeks from the first error, before giving up and not starting (*knock on wood*). I can probably make it back home to Austin if I do the following:
1) Ideally, only plug into low voltage home outlets. No supercharging. So the battery warmer ("preconditioning") is not triggered. (Best case for me is the hotel destination charger)
2) If you must supercharge, drive 15-20min to ensure the battery is warmed up first. Try not to supercharge in this cold (below 32F) where the battery must warm up aggressively.
3) If it goes limp, try the hard reset (power shutdown), unplug supercharger, which will disable the use of the battery warmer, and allowing you to drive again.
Wish us luck as we drive back to Austin! Hope this will help others debug and triage. Happy Holidays.
Problem: I was driving from Austin to Dallas, in this abnormally cold weather 10-22F. After supercharging at a stop, I received a brief BMS w305 error, service requested. It disappeared after a soft reset (two thumbs + brake). Once in Dallas, I supercharged in evening at 10F, 80% power, and then BMS w305 error appeared again, with low voltage may not start, plus air suspension disabled errors --- then while plugged into the supercharger MS bricked itself (touch screens worked, couldn't drive, nor unplug). I did another Soft Reset to reboot, allowing me to then unplug the supercharger. Then I did a hard reset (power down). Then I could drive it to the Tesla Service Center in Dallas. Where I parked it overnight until morning, uber back to my hotel. Shout out to Dallas Plano Service team! They squeezed me first thing to diagnose. Thank you!
Issue: BMS w305 means the battery warmer must be replaced. Tech said it was overworking at 10F to "precondition the battery" at the supercharger. It is a quick 30min install - if they have the part. Dallas doesn't have the part.
No Parts - How to Manage Issue - Tech's Suggestion: His advice was -- typically the component will last several weeks from the first error, before giving up and not starting (*knock on wood*). I can probably make it back home to Austin if I do the following:
1) Ideally, only plug into low voltage home outlets. No supercharging. So the battery warmer ("preconditioning") is not triggered. (Best case for me is the hotel destination charger)
2) If you must supercharge, drive 15-20min to ensure the battery is warmed up first. Try not to supercharge in this cold (below 32F) where the battery must warm up aggressively.
3) If it goes limp, try the hard reset (power shutdown), unplug supercharger, which will disable the use of the battery warmer, and allowing you to drive again.
Wish us luck as we drive back to Austin! Hope this will help others debug and triage. Happy Holidays.
