12V Battery Issues? Car not responsive? Try this!

[camalaio]

There's a lot of 12V battery issues occurring right now, so hopefully this helps someone.

Doing this is 100% safe and even documented in the Owner's Manual (section Roadside Assistance > Instructions for Transporters > Jump Starting the 12V Battery, page 228 at the time of writing for manual version 2020.20).

If you request a tow truck, do not let them drag the vehicle unless it is in Transport Mode, which requires the 12V system to be active. Some may be able to put the car on dollies without rotating the tires during loading or transport -- these are safe regardless of the 12V system state.

A few additional tips before the manual:

• You will need access to the frunk. Before you attempt the workaround in the manual, try...
  • On Android: Pop the frunk via the option on the persistent notification. This goes through Bluetooth unlike the rest of the app, and in some cases actually works when nothing else does.
  • On iOS: TBD
• The manual frunk unlock in the manual requires a 12V source. If you use a battery jumpstart pack, make sure it's ON when you attach it to the wires mentioned.
• Keycards may still work to get into the car. The screen may or may not work.
• One person had luck just by unplugging the Tesla charger from the car. Maybe you can also be this lucky!

Jumpstart Procedure (as of 2020.20 manual: pictures omitted here, present in manual):

1. Open the hood (see Opening Hood with No Power on page 20).
2. Remove the maintenance panel by pulling it upwards to release the trim clips that hold it in place.
3. Remove the cabin intake trim panel by pulling it upwards to release the trim clips that hold it in place.
4. Connect the 12V power supply's red positive (+) cable to the red positive (+) terminal on the 12V battery. CAUTION: To avoid damaging Model 3, do not allow the positive cable to contact other metal components, such as the battery tie-down bracket.
5. Connect the 12V power supply's black negative (-) cable to the black negative (-) terminal on the 12V battery.
6. Turn on the external power supply (refer to the manufacturer’s instructions). Touch the touchscreen to wake it up. NOTE: It may take several minutes to receive enough power to wake up the touchscreen.
7. When external 12V power is no longer required, disconnect both cables from the terminals on the 12V battery, beginning with the black negative (-) cable.
8. Replace the cabin intake trim panel by placing it back in its original location and pressing down until it is secure.
9. Replace the maintenance panel by placing it back in its original location and pressing down until it is secure.
10. Close the hood.

Credit to @Matsayz for the thread idea. Sticky not required but potentially appreciated due to surge in 12V issues?