How to turn a Model 3 LR 2021 off to install the OBD??

[cibermike]

Hi everyone,

I got my new M3 LR 2021 (MiC) a couple of weeks ago and I haven't been able to turn the car completely off (relay disconnected) so that I can install an OBD.
I've followed the steps described in many of the youtube videos but there is no way.

E.g:

These are the steps I do:
1. Keep the front and rear left doors (and windows) open.
2. Make sure that the sentry is disabled.
3. I disabled also the mobile access (and directly leaving my phone at home ).
4. Turn it off from Controls > Safety & Security
5. Wait for more than 4-5 minutes. I waited even for 15-20 minutes and nothing. The clunk relay sound does not happen nor the interior lights are turned off.

Although most of the times I've tested it in the garage where there is no connectivity (LTE & WiFi), I also tried it outside with the same result.

What am I doing wrong? I'm starting to think that the turn off sequence has been modified in the 2021 models compared to the previous ones.
Anyone with a M3 2021 has been able to do it? Any idea?

Thanks!

 

[GtiMart]

I believe I never heard the clunk when I tried to do this on my 2020 either. You could wait 30-60min for the car to fall asleep by itself, provided you left the doors closed (while staying inside) etc... I ended up plugging the cable anyway in the "off" state even though it wasn't technically off. I didn't get any errors.

 

[cibermike]

I believe I never heard the clunk when I tried to do this on my 2020 either. You could wait 30-60min for the car to fall asleep by itself, provided you left the doors closed (while staying inside) etc... I ended up plugging the cable anyway in the "off" state even though it wasn't technically off. I didn't get any errors.

Thanks a lot for your answer. I’am worried that I can damage something in the car if it is not turned off properly.

I will try it again in the next days. I’d like to confirm more experiences from people who never heard the clunk sound and, maybe, from 2021 owners.

 

[Timbo2]

Thanks a lot for your answer. I’am worried that I can damage something in the car if it is not turned off properly.

I will try it again in the next days. I’d like to confirm more experiences from people who never heard the clunk sound and, maybe, from 2021 owners.

I think you are correct. My car is a 2018 so I can't personally confirm. Looks like you need to pull the seat and disable the HV contactors.

BOOST 50, BOOST SR, BONUS & CUSTOM MODULE

 

[Taxvictim]

@Dolemite had a good post about how to disconnect all batteries.

"In the end, I basically "completely" turned the car off & on again. Stupid simple procedure - sounds scary, but isn't. Just be careful not to lock yourself out of the car, otherwise you'll have to open the frunk via the emergency leads behind the tow hitch as described in the manual.

1. Pop the frunk open
2. Open all windows to avoid any damage (since auto-up/down will be disabled)
3. Ensure the HVAC has been off for 30+ seconds
4. Power down the car thru the screen Controls > Safety & Security > Vehicle Power > Power Off

Then

1. Open the frunk, remove the under-hood apron
2. Disconnect the 12V battery negative terminal
3. Lift up the rear seat - there are two "sliding" latches on the leading edges under the cushion
4. On the right hand side, you'll notice a high-density foam block that covers the connector to the high-voltage battery (HVB)... lift it out of place to reveal the connector
5. Unlock the HVB connector by pivoting the little gray latch outwards - this will start pulling it out. At this point, the HVB connectors will immediately open and you'll hear a clunk - don't be alarmed.
6. Cover the connector port on the battery with a rag or something just to be safe (for the battery's sake)

The car is now effectively "dead." I left it like this for 30 - 45 mins, reconnected everything in the reverse order, and now it's fine.
I left the rear right door cracked so I wouldn't have to worry about a lockout condition."

 

[cibermike]

Hi guys,

I was finally able to turn it off and put the obdlink. I drove outside my garage (where I don’t have 3g signal nor wifi, dunno if it has something to do) and followed the following steps:
1. Open the 4 doors and windows.
2. Disable mobile access.
3. Disable sentry.
4. Turn off from the console.

After exactly 2 minutes I heard the “clonk” that I didn’t hear these last days. I waited some more minutes (around 10 minutes, just in case).

I removed the plastic cover, connect the cables and the obdlink and voila… data read in Scanmytesla.

Thanks everyone!

 

[thinger]

Sorru that I bump this thread but what kind of damage can happen if you disconnect that cable on fly?
I think there is only 12v lines?